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Liang S, Zhao Z, Liu L, Zhang Y, Liu X. Research Progress on the Mechanisms of Protocatechuic Acid in the Treatment of Cognitive Impairment. Molecules 2024; 29:4724. [PMID: 39407652 PMCID: PMC11478363 DOI: 10.3390/molecules29194724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2024] [Revised: 09/25/2024] [Accepted: 10/03/2024] [Indexed: 10/20/2024] Open
Abstract
Cognitive impairment (CI) is a type of mental health disorder that mainly affects cognitive abilities, such as learning, memory, perception, and problem-solving. Currently, in clinical practice, the treatment of cognitive impairment mainly focuses on the application of cholinesterase inhibitors and NMDA receptor antagonists; however, there is no specific and effective drug yet. Procatechuic acid (PCA) possesses various functions, including antibacterial, antiasthmatic, and expectorant effects. In recent years, it has received growing attention in the cognitive domain. Therefore, by summarizing the mechanisms of action of procatechuic acid in the treatment of cognitive impairment in this paper, it is found that procatechuic acid has multiple effects, such as regulating the expression of neuroprotective factors, inhibiting cell apoptosis, promoting the autophagy-lysosome pathway, suppressing oxidative stress damage, inhibiting inflammatory responses, improving synaptic plasticity dysfunction, inhibiting Aβ deposition, reducing APP hydrolysis, enhancing the cholinergic system, and inhibiting the excitotoxicity of neuronal cells. The involved signaling pathways include activating Pi3K-akt-mTor and inhibiting JNK, P38 MAPK, P38-ERK-JNK, SIRT1, and NF-κB/p53, etc. This paper aims to present the latest progress in research on procatechuic acid, including aspects such as its chemical properties, sources, pharmacokinetics, mechanisms for treating neurodegenerative diseases.
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Affiliation(s)
- Shuzhi Liang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China; (S.L.)
| | - Zhongmin Zhao
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China; (S.L.)
| | - Leilei Liu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China; (S.L.)
| | - Yan Zhang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China; (S.L.)
- The Youth Research and Innovation Team of TCM for the Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
| | - Xijian Liu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China; (S.L.)
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Tarbox HE, Branch A, Fried SD. Cognition-Associated Protein Structural Changes in a Rat Model of Aging are Related to Reduced Refolding Capacity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.20.614172. [PMID: 39386726 PMCID: PMC11463556 DOI: 10.1101/2024.09.20.614172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
Cognitive decline during aging represents a major societal burden, causing both personal and economic hardship in an increasingly aging population. There are a few well-known proteins that can misfold and aggregate in an age-dependent manner, such as amyloid β and α-synuclein. However, many studies have found that the proteostasis network, which functions to keep proteins properly folded, is impaired with age, suggesting that there may be many more proteins that incur structural alterations with age. Here, we used limited-proteolysis mass spectrometry (LiP-MS), a structural proteomic method, to globally interrogate protein conformational changes in a rat model of cognitive aging. Specifically, we compared soluble hippocampal proteins from aged rats with preserved cognition to those from aged rats with impaired cognition. We identified several hundred proteins as having undergone cognition-associated structural changes (CASCs). We report that CASC proteins are substantially more likely to be nonrefoldable than non-CASC proteins, meaning they typically cannot spontaneously refold to their native conformations after being chemically denatured. The potentially cofounding variable of post-translational modifications is systematically addressed, and we find that oxidation and phosphorylation cannot significantly explain the limited proteolysis signal. These findings suggest that noncovalent, conformational alterations may be general features in cognitive decline, and more broadly, that proteins need not form amyloids for their misfolded states to be relevant to age-related deterioration in cognitive abilities.
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Affiliation(s)
- Haley E. Tarbox
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Audrey Branch
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Stephen D. Fried
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
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Méndez P, de la Vega-Ruiz R, Montes-Mellado A. Estrogenic regulation of hippocampal inhibitory system across lifespan. J Neuroendocrinol 2024:e13441. [PMID: 39143852 DOI: 10.1111/jne.13441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/08/2024] [Accepted: 08/01/2024] [Indexed: 08/16/2024]
Abstract
Estrogens produced in peripheral tissues and locally in the brain are potent neuromodulators. The function of the hippocampus, a brain region essential for episodic memory and spatial navigation, relies on the activity of ensembles of excitatory neurons whose activity is temporally and spatially coordinated by a wide diversity of inhibitory neurons (INs) types. Over the last years, we have accumulated evidence that indicates that estrogens regulate the function of hippocampal INs through different mechanisms, including transcriptional regulation and rapid nongenomic signaling. Here, we argue that the well-documented influence of estrogens on episodic memory may be related to the actions of local and peripheral estrogens on the heterogenous populations of hippocampal INs. We discuss how physiological changes in peripheral sex hormone levels throughout lifespan may interact with local brain sources to regulate IN function at different stages of life, from early hippocampal development to the aging brain. We conclude that considering INs as mediators of sex hormone actions in the hippocampus across the healthy life span will benefit our understanding of sex-biased neurodevelopmental disorders and physiological aging.
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Junghans K, Wyeth M, Buckmaster PS. Rat strain differences in seizure frequency and hilar neuron loss after systemic treatment with pilocarpine. Epilepsy Res 2024; 204:107384. [PMID: 38879905 PMCID: PMC11253724 DOI: 10.1016/j.eplepsyres.2024.107384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/13/2024] [Accepted: 05/29/2024] [Indexed: 06/18/2024]
Abstract
At least 3 months after systemic treatment with pilocarpine to induce status epilepticus, Long-Evans and Sprague-Dawley rats were video-EEG monitored for seizures continuously for 1 month. Rats were then perfused, hippocampi were processed for Nissl staining, and hilar neurons were quantified. Seizure frequency in Long-Evans rats was 1/10th of that in Sprague-Dawley rats, and more variable. Hilar neuron loss was also less severe in Long-Evans rats. However, there was no correlation between hilar neuron loss and seizure frequency in either strain. The low and variable seizure frequency suggests limited usefulness of pilocarpine-treated Long-Evans rats for some epilepsy experiments.
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Affiliation(s)
- Kristina Junghans
- Departments of Comparative Medicine, Stanford University, 3172 Porter Drive, Palo Alto, CA 94304-5475, USA
| | - Megan Wyeth
- Departments of Comparative Medicine, Stanford University, 3172 Porter Drive, Palo Alto, CA 94304-5475, USA.
| | - Paul S Buckmaster
- Departments of Comparative Medicine, Stanford University, 3172 Porter Drive, Palo Alto, CA 94304-5475, USA; Departments of Neurology & Neurological Sciences, Stanford University, 3172 Porter Drive, Palo Alto, CA 94304-5475, USA
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de Ávila C, Gugula A, Trenk A, Intorcia AJ, Suazo C, Nolz J, Plamondon J, Khatri D, Tallant L, Caron A, Blasiak A, Serrano GE, Beach TG, Gundlach AL, Mastroeni DF. Unveiling a novel memory center in human brain: neurochemical identification of the nucleus incertus, a key pontine locus implicated in stress and neuropathology. Biol Res 2024; 57:46. [PMID: 39014514 PMCID: PMC11253401 DOI: 10.1186/s40659-024-00523-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 06/07/2024] [Indexed: 07/18/2024] Open
Abstract
BACKGROUND The nucleus incertus (NI) was originally described by Streeter in 1903, as a midline region in the floor of the fourth ventricle of the human brain with an 'unknown' function. More than a century later, the neuroanatomy of the NI has been described in lower vertebrates, but not in humans. Therefore, we examined the neurochemical anatomy of the human NI using markers, including the neuropeptide, relaxin-3 (RLN3), and began to explore the distribution of the NI-related RLN3 innervation of the hippocampus. METHODS Histochemical staining of serial, coronal sections of control human postmortem pons was conducted to reveal the presence of the NI by detection of immunoreactivity (IR) for the neuronal markers, microtubule-associated protein-2 (MAP2), glutamic acid dehydrogenase (GAD)-65/67 and corticotrophin-releasing hormone receptor 1 (CRHR1), and RLN3, which is highly expressed in NI neurons in diverse species. RLN3 and vesicular GABA transporter 1 (vGAT1) mRNA were detected by fluorescent in situ hybridization. Pons sections containing the NI from an AD case were immunostained for phosphorylated-tau, to explore potential relevance to neurodegenerative diseases. Lastly, sections of the human hippocampus were stained to detect RLN3-IR and somatostatin (SST)-IR. RESULTS In the dorsal, anterior-medial region of the human pons, neurons containing RLN3- and MAP2-IR, and RLN3/vGAT1 mRNA-positive neurons were observed in an anatomical pattern consistent with that of the NI in other species. GAD65/67- and CRHR1-immunopositive neurons were also detected within this area. Furthermore, RLN3- and AT8-IR were co-localized within NI neurons of an AD subject. Lastly, RLN3-IR was detected in neurons within the CA1, CA2, CA3 and DG areas of the hippocampus, in the absence of RLN3 mRNA. In the DG, RLN3- and SST-IR were co-localized in a small population of neurons. CONCLUSIONS Aspects of the anatomy of the human NI are shared across species, including a population of stress-responsive, RLN3-expressing neurons and a RLN3 innervation of the hippocampus. Accumulation of phosphorylated-tau in the NI suggests its possible involvement in AD pathology. Further characterization of the neurochemistry of the human NI will increase our understanding of its functional role in health and disease.
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Affiliation(s)
- Camila de Ávila
- Arizona State University-Banner Neurodegenerative Disease Research Center, Tempe, AZ, USA.
| | - Anna Gugula
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Aleksandra Trenk
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Anthony J Intorcia
- Arizona Alzheimer's Consortium, Phoenix, AZ, USA
- Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Crystal Suazo
- Arizona State University-Banner Neurodegenerative Disease Research Center, Tempe, AZ, USA
| | - Jennifer Nolz
- Arizona State University-Banner Neurodegenerative Disease Research Center, Tempe, AZ, USA
| | | | - Divyanshi Khatri
- Arizona State University-Banner Neurodegenerative Disease Research Center, Tempe, AZ, USA
| | - Lauren Tallant
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ, USA
| | - Alexandre Caron
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Geidy E Serrano
- Arizona Alzheimer's Consortium, Phoenix, AZ, USA
- Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Thomas G Beach
- Arizona Alzheimer's Consortium, Phoenix, AZ, USA
- Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Andrew L Gundlach
- Florey Department of Neuroscience and Mental Health and Department of Anatomy and Physiology and The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Diego F Mastroeni
- Arizona State University-Banner Neurodegenerative Disease Research Center, Tempe, AZ, USA
- Arizona Alzheimer's Consortium, Phoenix, AZ, USA
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Shigapova RR, Mukhamedshina YO. Electrophysiology Methods for Assessing of Neurodegenerative and Post-Traumatic Processes as Applied to Translational Research. Life (Basel) 2024; 14:737. [PMID: 38929721 PMCID: PMC11205106 DOI: 10.3390/life14060737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
Electrophysiological studies have long established themselves as reliable methods for assessing the functional state of the brain and spinal cord, the degree of neurodegeneration, and evaluating the effectiveness of therapy. In addition, they can be used to diagnose, predict functional outcomes, and test the effectiveness of therapeutic and rehabilitation programs not only in clinical settings, but also at the preclinical level. Considering the urgent need to develop potential stimulators of neuroregeneration, it seems relevant to obtain objective data when modeling neurological diseases in animals. Thus, in the context of the application of electrophysiological methods, not only the comparison of the basic characteristics of bioelectrical activity of the brain and spinal cord in humans and animals, but also their changes against the background of neurodegenerative and post-traumatic processes are of particular importance. In light of the above, this review will contribute to a better understanding of the results of electrophysiological assessment in neurodegenerative and post-traumatic processes as well as the possibility of translating these methods from model animals to humans.
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Affiliation(s)
- Rezeda Ramilovna Shigapova
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan 420008, Russia;
| | - Yana Olegovna Mukhamedshina
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan 420008, Russia;
- Department of Histology, Cytology and Embryology, Kazan State Medical University, Kazan 420012, Russia
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Sagheddu C, Stojanovic T, Kouhnavardi S, Savchenko A, Hussein AM, Pistis M, Monje FJ, Plasenzotti R, Aufy M, Studenik CR, Lubec J, Lubec G. Cognitive performance in aged rats is associated with differences in distinctive neuronal populations in the ventral tegmental area and altered synaptic plasticity in the hippocampus. Front Aging Neurosci 2024; 16:1357347. [PMID: 38469164 PMCID: PMC10926450 DOI: 10.3389/fnagi.2024.1357347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
Abstract
Introduction Deterioration of cognitive functions is commonly associated with aging, although there is wide variation in the onset and manifestation. Albeit heterogeneity in age-related cognitive decline has been studied at the cellular and molecular level, there is poor evidence for electrophysiological correlates. The aim of the current study was to address the electrophysiological basis of heterogeneity of cognitive functions in cognitively Inferior and Superior old (19-20 months) rats in the ventral tegmental area (VTA) and the hippocampus, having Young (12 weeks) rats as a control. The midbrain VTA operates as a hub amidst affective and cognitive facets, processing sensory inputs related to motivated behaviours and hippocampal memory. Increasing evidence shows direct dopaminergic and non-dopaminergic input from the VTA to the hippocampus. Methods Aged Superior and Inferior male rats were selected from a cohort of 88 animals based on their performance in a spatial learning and memory task. Using in vivo single-cell recording in the VTA, we examined the electrical activity of different neuronal populations (putative dopaminergic, glutamatergic and GABAergic neurons). In the same animals, basal synaptic transmission and synaptic plasticity were examined in hippocampal slices. Results Electrophysiological recordings from the VTA and hippocampus showed alterations associated with aging per se, together with differences specifically linked to the cognitive status of aged animals. In particular, the bursting activity of dopamine neurons was lower, while the firing frequency of glutamatergic neurons was higher in VTA of Inferior old rats. The response to high-frequency stimulation in hippocampal slices also discriminated between Superior and Inferior aged animals. Discussion This study provides new insight into electrophysiological information underlying compromised cerebral ageing. Further understanding of brain senescence, possibly related to neurocognitive decline, will help develop new strategies towards the preservation of a high quality of life.
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Affiliation(s)
- Claudia Sagheddu
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Tamara Stojanovic
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Shima Kouhnavardi
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Artem Savchenko
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
- Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia
| | - Ahmed M. Hussein
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Department of Zoology, Faculty of Science, Al-Azhar University, Asyut, Egypt
| | - Marco Pistis
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
- Section of Cagliari, Neuroscience Institute National Research Council of Italy (CNR), Cagliari, Italy
- Unit of Clinical Pharmacology, University Hospital, Cagliari, Italy
| | - Francisco J. Monje
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Roberto Plasenzotti
- Division of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Mohammed Aufy
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Christian R. Studenik
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Jana Lubec
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Gert Lubec
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
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Nagarajan R, Lyu J, Kambali M, Wang M, Courtney CD, Christian-Hinman CA, Rudolph U. Genetic Ablation of Dentate Hilar Somatostatin-Positive GABAergic Interneurons is Sufficient to Induce Cognitive Impairment. Mol Neurobiol 2024; 61:567-580. [PMID: 37642935 PMCID: PMC11285310 DOI: 10.1007/s12035-023-03586-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023]
Abstract
Aging is often associated with a decline in cognitive function. A reduction in the number of somatostatin-positive (SOM+) interneurons in the dentate gyrus (DG) has been described in cognitively impaired but not in unimpaired aged rodents. However, it remains unclear whether the reduction in SOM + interneurons in the DG hilus is causal for age-related cognitive dysfunction. We hypothesized that hilar SOM+ interneurons play an essential role in maintaining cognitive function and that a reduction in the number of hilar SOM + interneurons might be sufficient to induce cognitive dysfunction. Hilar SOM+ interneurons were ablated by expressing a diphtheria toxin transgene specifically in these interneurons, which resulted in a reduction in the number of SOM+ /GAD-67+ neurons and dendritic spine density in the DG. C-fos and Iba-1 immunostainings were increased in DG and CA3, but not CA1, and BDNF protein expression in the hippocampus was decreased. Behavioral testing showed a reduced recognition index in the novel object recognition test, decreased alternations in the Y maze test, and longer latencies and path lengths in the learning and reversal learning phases of the Morris water maze. Our results show that partial genetic ablation of SOM+ hilar interneurons is sufficient to increase activity in DG and CA3, as has been described to occur with aging and to induce an impairment of learning and memory functions. Thus, partial ablation of hilar SOM + interneurons may be a significant contributing factor to age-related cognitive dysfunction. These mice may also be useful as a cellularly defined model of hippocampal aging.
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Affiliation(s)
- Rajasekar Nagarajan
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jinrui Lyu
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Maltesh Kambali
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Muxiao Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Connor D Courtney
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Catherine A Christian-Hinman
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Uwe Rudolph
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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Bañuelos C, Kittleson JR, LaNasa KH, Galiano CS, Roth SM, Perez EJ, Long JM, Roberts MT, Fong S, Rapp PR. Cognitive Aging and the Primate Basal Forebrain Revisited: Disproportionate GABAergic Vulnerability Revealed. J Neurosci 2023; 43:8425-8441. [PMID: 37798131 PMCID: PMC10711728 DOI: 10.1523/jneurosci.0456-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 09/22/2023] [Accepted: 09/23/2023] [Indexed: 10/07/2023] Open
Abstract
Basal forebrain (BF) projections to the hippocampus and cortex are anatomically positioned to influence a broad range of cognitive capacities that are known to decline in normal aging, including executive function and memory. Although a long history of research on neurocognitive aging has focused on the role of the cholinergic basal forebrain system, intermingled GABAergic cells are numerically as prominent and well positioned to regulate the activity of their cortical projection targets, including the hippocampus and prefrontal cortex. The effects of aging on noncholinergic BF neurons in primates, however, are largely unknown. In this study, we conducted quantitative morphometric analyses in brains from young adult (6 females, 2 males) and aged (11 females, 5 males) rhesus monkeys (Macaca mulatta) that displayed significant impairment on standard tests that require the prefrontal cortex and hippocampus. Cholinergic (ChAT+) and GABAergic (GAD67+) neurons were quantified through the full rostrocaudal extent of the BF. Total BF immunopositive neuron number (ChAT+ plus GAD67+) was significantly lower in aged monkeys compared with young, largely because of fewer GAD67+ cells. Additionally, GAD67+ neuron volume was greater selectively in aged monkeys without cognitive impairment compared with young monkeys. These findings indicate that the GABAergic component of the primate BF is disproportionally vulnerable to aging, implying a loss of inhibitory drive to cortical circuitry. Moreover, adaptive reorganization of the GABAergic circuitry may contribute to successful neurocognitive outcomes.SIGNIFICANCE STATEMENT A long history of research has confirmed the role of the basal forebrain in cognitive aging. The majority of that work has focused on BF cholinergic neurons that innervate the cortical mantle. Codistributed BF GABAergic populations are also well positioned to influence cognitive function, yet little is known about this prominent neuronal population in the aged brain. In this unprecedented quantitative comparison of both cholinergic and GABAergic BF neurons in young and aged rhesus macaques, we found that neuron number is significantly reduced in the aged BF compared with young, and that this reduction is disproportionately because of a loss of GABAergic neurons. Together, our findings encourage a new perspective on the functional organization of the primate BF in neurocognitive aging.
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Affiliation(s)
- Cristina Bañuelos
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Joshua R Kittleson
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Katherine H LaNasa
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Christina S Galiano
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Stephanie M Roth
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Evelyn J Perez
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Jeffrey M Long
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
| | - Mary T Roberts
- California National Primate Research Center, University of California, Davis, Davis, California 95616
| | - Sania Fong
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
- California National Primate Research Center, University of California, Davis, Davis, California 95616
| | - Peter R Rapp
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224
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10
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Weiler M, Stieger KC, Shroff K, Klein JP, Wood WH, Zhang Y, Chandrasekaran P, Lehrmann E, Camandola S, Long JM, Mattson MP, Becker KG, Rapp PR. Transcriptional changes in the rat brain induced by repetitive transcranial magnetic stimulation. Front Hum Neurosci 2023; 17:1215291. [PMID: 38021223 PMCID: PMC10679736 DOI: 10.3389/fnhum.2023.1215291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 10/03/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Transcranial Magnetic Stimulation (TMS) is a noninvasive technique that uses pulsed magnetic fields to affect the physiology of the brain and central nervous system. Repetitive TMS (rTMS) has been used to study and treat several neurological conditions, but its complex molecular basis is largely unexplored. Methods Utilizing three experimental rat models (in vitro, ex vivo, and in vivo) and employing genome-wide microarray analysis, our study reveals the extensive impact of rTMS treatment on gene expression patterns. Results These effects are observed across various stimulation protocols, in diverse tissues, and are influenced by time and age. Notably, rTMS-induced alterations in gene expression span a wide range of biological pathways, such as glutamatergic, GABAergic, and anti-inflammatory pathways, ion channels, myelination, mitochondrial energetics, multiple neuron-and synapse-specific genes. Discussion This comprehensive transcriptional analysis induced by rTMS stimulation serves as a foundational characterization for subsequent experimental investigations and the exploration of potential clinical applications.
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Affiliation(s)
- Marina Weiler
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kevin C. Stieger
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kavisha Shroff
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Jessie P. Klein
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - William H. Wood
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Yongqing Zhang
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Prabha Chandrasekaran
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Elin Lehrmann
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Simonetta Camandola
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Jeffrey M. Long
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Mark P. Mattson
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kevin G. Becker
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Peter R. Rapp
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
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11
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Klinger K, del Ángel M, Çalışkan G, Stork O. Increasing NPYergic transmission in the hippocampus rescues aging-related deficits of long-term potentiation in the mouse dentate gyrus. Front Aging Neurosci 2023; 15:1283581. [PMID: 38020778 PMCID: PMC10673643 DOI: 10.3389/fnagi.2023.1283581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023] Open
Abstract
Loss of neuropeptide Y (NPY)-expressing interneurons in the hippocampus and decaying cholinergic neuromodulation are thought to contribute to impaired cognitive function during aging. However, the interaction of these two neuromodulatory systems in maintaining hippocampal synaptic plasticity during healthy aging has not been explored so far. Here we report profound sex differences in the Neuropeptide-Y (NPY) levels in the dorsal dentate gyrus (DG) with higher NPY concentrations in the male mice compared to their female counterparts and a reduction of NPY levels during aging specifically in males. This change in aged males is accompanied by a deficit in theta burst-induced long-term potentiation (LTP) in the medial perforant path-to-dorsal DG (MPP-DG) synapse, which can be rescued by enhancing cholinergic activation with the acetylcholine esterase blocker, physostigmine. Importantly, NPYergic transmission is required for this rescue of LTP. Moreover, exogenous NPY application alone is sufficient to recover LTP induction in aged male mice, even in the absence of the cholinergic stimulator. Together, our results suggest that in male mice NPYergic neurotransmission is a critical factor for maintaining dorsal DG LTP during aging.
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Affiliation(s)
- Katharina Klinger
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Research Group “Synapto-Oscillopathies”, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Miguel del Ángel
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
| | - Gürsel Çalışkan
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Research Group “Synapto-Oscillopathies”, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Oliver Stork
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
- Center for Intervention and Research on Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Magdeburg, Germany
- German Center for Mental Health (DZPG), Magdeburg, Germany
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12
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Gray DT, Zempare M, Carey N, Khattab S, Sinakevitch I, De Biase LM, Barnes CA. Extracellular matrix proteoglycans support aged hippocampus networks: a potential cellular-level mechanism of brain reserve. Neurobiol Aging 2023; 131:52-58. [PMID: 37572527 PMCID: PMC10529564 DOI: 10.1016/j.neurobiolaging.2023.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 07/12/2023] [Accepted: 07/14/2023] [Indexed: 08/14/2023]
Abstract
One hallmark of normative brain aging is vast heterogeneity in whether older people succumb to or resist cognitive decline. Resilience describes a brain's capacity to maintain cognition in the face of aging and disease. One factor influencing resilience is brain reserve-the status of neurobiological resources available to support neuronal circuits as dysfunction accumulates. This study uses a cohort of behaviorally characterized adult, middle-aged, and aged rats to test whether neurobiological factors that protect inhibitory neurotransmission and synapse function represent key components of brain reserve. Histochemical analysis of extracellular matrix proteoglycans, which play critical roles in stabilizing synapses and modulating inhibitory neuron excitability, was conducted alongside analyses of lipofuscin-associated autofluorescence. The findings indicate that aging results in lower proteoglycan density and more lipofuscin in CA3. Aged rats with higher proteoglycan density exhibited better performance on the Morris watermaze, whereas lipofuscin abundance was not related to spatial memory. These data suggest that the local environment around neurons may protect against synapse dysfunction or hyperexcitability and could contribute to brain reserve mechanisms.
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Affiliation(s)
- Daniel T Gray
- Department of Physiology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Marc Zempare
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Natalie Carey
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Salma Khattab
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Irina Sinakevitch
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Lindsay M De Biase
- Department of Physiology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Carol A Barnes
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA; Departments of Psychology, Neurology and Neuroscience, University of Arizona, Tucson, AZ, USA.
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13
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DuBois DW, Murchison DA, Mahnke AH, Bang E, Winzer-Serhan U, Griffith WH, Souza KA. Maintenance of optogenetic channel rhodopsin (ChR2) function in aging mice: Implications for pharmacological studies of inhibitory synaptic transmission, quantal content, and calcium homeostasis. Neuropharmacology 2023:109651. [PMID: 37414332 DOI: 10.1016/j.neuropharm.2023.109651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/23/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Disruption of synaptic function is believed to represent a common pathway contributing to cognitive decline during aging. Optogenetics is a prodigious tool for studying relationships between function and synaptic circuitry but models utilizing viral vectors present limitations. Careful characterization of the functionality of channel rhodopsin in transgenic models is crucial for determining whether they can be used across aging. This includes verifying the light sensitivity of the protein and confirming its ability to generate action potentials in response to light stimulation. We combined in vitro optogenetic methodology and a reduced synaptic preparation of acutely isolated neurons to determine if the ChR2(H134R)-eYFP vGAT mouse model is well-suited for aging studies. We used neurons from young (2-6 mo), middle-aged (10-14 mo) and aged (17-25 mo) bacterial artificial chromosome (BAC) transgenic mouse line with stable expression of the channelrhodopsin-2 (ChR2) variant H134R in GABAergic cell populations. Cellular physiology and calcium dynamics were assessed in basal forebrain (BF) neurons using patch-clamp recording and fura-2 microfluorimetry, alongside 470 nm light stimulation of the transgenic ChR2 channel to characterize a wide array of physiological functions known to decline with age. We found ChR2 expression is functionally maintained across aging, while spontaneous and optically evoked inhibitory postsynaptic currents, and quantal content were decreased. Aged mice also showed an increase in intracellular calcium buffering. These results, which are on par with previous observations, demonstrate that the optogenetic vGAT BAC mouse model is well-suited for investigating age-related changes in calcium signaling and synaptic transmission.
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Affiliation(s)
- Dustin W DuBois
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - David A Murchison
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - Amanda H Mahnke
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - Eunyoung Bang
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - Ursula Winzer-Serhan
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - William H Griffith
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA
| | - Karienn A Souza
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, USA.
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14
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Lyu J, Nagarajan R, Kambali M, Wang M, Rudolph U. Selective inhibition of somatostatin-positive dentate hilar interneurons induces age-related cellular changes and cognitive dysfunction. PNAS NEXUS 2023; 2:pgad134. [PMID: 37168673 PMCID: PMC10165806 DOI: 10.1093/pnasnexus/pgad134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/19/2023] [Accepted: 04/04/2023] [Indexed: 05/13/2023]
Abstract
The cellular basis of age-related impairments of hippocampal function is not fully understood. In order to evaluate the role of somatostatin-positive (Sst+) interneurons in the dentate gyrus (DG) hilus in this process, we chemogenetically inhibited Sst+ interneurons in the DG hilus. Chronic chemogenetic inhibition (CCI) of these neurons resulted in increased c-Fos staining in the DG hilus, a decrease in the percentage of GAD67- and of Sst-expressing interneurons in the DG, and increased microglial activation in DG, CA3, and CA1. Total dendritic length and spine density were reduced in DG and CA1, suggesting reduced dendritic complexity. Behaviorally, the recognition index in an object recognition task and the percentage of spontaneous alternations in the Y-maze were decreased, while in both initial and reversal learning in the Morris water maze, the latencies to find the hidden platform were increased, suggesting cognitive dysfunction. Our findings establish a causal role for a reduced function of Sst+ interneurons in the DG hilus for cognitive decline and suggest that this reduced function may contribute to age-related impairments of learning and memory. Furthermore, our CCI mice may represent a cellularly defined model of hippocampal aging.
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Affiliation(s)
- Jinrui Lyu
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
- Neuroscience Program, College of Liberal Arts and Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
| | - Rajasekar Nagarajan
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
| | - Maltesh Kambali
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
| | - Muxiao Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
- Neuroscience Program, College of Liberal Arts and Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802-6178, USA
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Gray DT, Khattab S, Meltzer J, McDermott K, Schwyhart R, Sinakevitch I, Härtig W, Barnes CA. Retrosplenial cortex microglia and perineuronal net densities are associated with memory impairment in aged rhesus macaques. Cereb Cortex 2023; 33:4626-4644. [PMID: 36169578 PMCID: PMC10110451 DOI: 10.1093/cercor/bhac366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Synapse loss and altered plasticity are significant contributors to memory loss in aged individuals. Microglia, the innate immune cells of the brain, play critical roles in maintaining synapse function, including through a recently identified role in regulating the brain extracellular matrix. This study sought to determine the relationship between age, microglia, and extracellular matrix structure densities in the macaque retrosplenial cortex. Twenty-nine macaques ranging in age from young adult to aged were behaviorally characterized on 3 distinct memory tasks. Microglia, parvalbumin (PV)-expressing interneurons and extracellular matrix structures, known as perineuronal nets (PNNs), were immuno- and histochemically labeled. Our results indicate that microglia densities increase in the retrosplenial cortex of aged monkeys, while the proportion of PV neurons surrounded by PNNs decreases. Aged monkeys with more microglia had fewer PNN-associated PV neurons and displayed slower learning and poorer performance on an object recognition task. Stepwise regression models using age and the total density of aggrecan, a chondroitin sulfate proteoglycan of PNNs, better predicted memory performance than did age alone. Together, these findings indicate that elevated microglial activity in aged brains negatively impacts cognition in part through mechanisms that alter PNN assembly in memory-associated brain regions.
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Affiliation(s)
- Daniel T Gray
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Salma Khattab
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Jeri Meltzer
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Kelsey McDermott
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Rachel Schwyhart
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig 04103, Germany
| | - Irina Sinakevitch
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig 04103, Germany
| | - Carol A Barnes
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States
- Departments of Psychology, Neurology and Neuroscience, University of Arizona, Tucson, AZ 85721, United States
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16
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Adams JN, Márquez F, Larson MS, Janecek JT, Miranda BA, Noche JA, Taylor L, Hollearn MK, McMillan L, Keator DB, Head E, Rissman RA, Yassa MA. Differential involvement of hippocampal subfields in the relationship between Alzheimer's pathology and memory interference in older adults. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2023; 15:e12419. [PMID: 37035460 PMCID: PMC10075195 DOI: 10.1002/dad2.12419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/15/2023] [Accepted: 02/28/2023] [Indexed: 04/11/2023]
Abstract
Introduction We tested whether Alzheimer's disease (AD) pathology predicts memory deficits in non-demented older adults through its effects on medial temporal lobe (MTL) subregional volume. Methods Thirty-two, non-demented older adults with cerebrospinal fluid (CSF) (amyloid-beta [Aβ]42/Aβ40, phosphorylated tau [p-tau]181, total tau [t-tau]), positron emission tomography (PET; 18F-florbetapir), high-resolution structural magnetic resonance imaging (MRI), and neuropsychological assessment were analyzed. We examined relationships between biomarkers and a highly granular measure of memory consolidation, retroactive interference (RI). Results Biomarkers of AD pathology were related to RI. Dentate gyrus (DG) and CA3 volume were uniquely associated with RI, whereas CA1 and BA35 volume were related to both RI and overall memory recall. AD pathology was associated with reduced BA35, CA1, and subiculum volume. DG volume and Aβ were independently associated with RI, whereas CA1 volume mediated the relationship between AD pathology and RI. Discussion Integrity of distinct hippocampal subfields demonstrate differential relationships with pathology and memory function, indicating specificity in vulnerability and contribution to different memory processes.
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Affiliation(s)
- Jenna N. Adams
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Freddie Márquez
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Myra S. Larson
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - John T. Janecek
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Blake A. Miranda
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Jessica A. Noche
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Lisa Taylor
- Department of Psychiatry and Human BehaviorUniversity of CaliforniaIrvineCaliforniaUSA
| | - Martina K. Hollearn
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - Liv McMillan
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
| | - David B. Keator
- Department of Psychiatry and Human BehaviorUniversity of CaliforniaIrvineCaliforniaUSA
| | - Elizabeth Head
- Department of Pathology and Laboratory MedicineUniversity of CaliforniaIrvineCaliforniaUSA
- Department of NeurologyUniversity of CaliforniaIrvineCaliforniaUSA
- Department of NeurologyUniversity of KentuckyLexingtonKentuckyUSA
| | - Robert A. Rissman
- Department of NeurosciencesUniversity of CaliforniaSan DiegoCaliforniaUSA
- Veterans Affairs San Diego Healthcare SystemSan DiegoCaliforniaUSA
| | - Michael A. Yassa
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and MemoryUniversity of CaliforniaIrvineCaliforniaUSA
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17
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DiCola NM, Lacy AL, Bishr OJ, Kimsey KM, Whitney JL, Lovett SD, Burke SN, Maurer AP. Advanced age has dissociable effects on hippocampal CA1 ripples and CA3 high frequency events in male rats. Neurobiol Aging 2022; 117:44-58. [PMID: 35665647 PMCID: PMC9392897 DOI: 10.1016/j.neurobiolaging.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 02/01/2023]
Abstract
Sharp wave/ripples/high frequency events (HFEs) are transient bursts of depolarization in hippocampal subregions CA3 and CA1 that occur during rest and pauses in behavior. Previous studies have reported that CA1 ripples in aged rats have lower frequency than those detected in young animals. While CA1 ripples are thought to be driven by CA3, HFEs in CA3 have not been examined in aged animals. The current study obtained simultaneous recordings from CA1 and CA3 in young and aged rats to examine sharp wave/ripples/HFEs in relation to age. While CA1 ripple frequency was reduced with age, there were no age differences in the frequency of CA3 HFEs, although power and length were lower in old animals. While there was a proportion of CA1 ripples that co-occurred with a CA3 HFE, none of the age-related differences in CA1 ripples could be explained by alterations in CA3 HFE characteristics. These findings suggest that age differences in CA1 are not due to altered CA3 activity, but instead reflect distinct mechanisms of ripple generation with age.
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Affiliation(s)
- Nicholas M. DiCola
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Alexa L. Lacy
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Omar J. Bishr
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Kathryn M. Kimsey
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Jenna L. Whitney
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Sarah D. Lovett
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Sara N. Burke
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA,Corresponding author at: University of Florida, Neuroscience, McKnight Brain Institute, P.O. Box 100244, 1149 Newell Dr, RM L1-100G, Gainesville, FL 32610, USA. (S.N. Burke)
| | - Andrew P. Maurer
- Evelyn F. McKnight McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL, USA,Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA,Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL, USA,Corresponding author at: McKnight Brain Institute, 1149 Newell Dr, RM L1-100E, University of Florida, Gainesville, FL 32610, USA. (A.P. Maurer)
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18
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Cooper TL, Thompson JJ, Turner SM, Watson C, Lubke KN, Logan CN, Maurer AP, Burke SN. Unilateral Perforant Path Transection Does Not Alter Lateral Entorhinal Cortical or Hippocampal CA3 Arc Expression. Front Syst Neurosci 2022; 16:920713. [PMID: 35844245 PMCID: PMC9279555 DOI: 10.3389/fnsys.2022.920713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
It is well established that degradation of perforant path fibers is associated with age-related cognitive dysfunction and CA3 hyperactivity. Whether this fiber loss triggers a cascade of other functional changes within the hippocampus circuit has not been causatively established, however. Thus, the current study evaluated the effect of perforant path fiber loss on neuronal activity in CA3 and layer II of the lateral entorhinal cortex (LEC) in relation to mnemonic similarity task performance. Expression of the immediate early gene Arc was quantified in rats that received a unilateral right hemisphere transection of the perforant path or sham surgery that cut the cortex but left the fibers intact. Behavior-related expression of Arc mRNA was measured to test the hypothesis that fiber loss leads to elevated activation of CA3 and LEC neurons, as previously observed in aged rats that were impaired on the mnemonic similarity task. Transection of perforant path fibers, which has previously been shown to lead to a decline in mnemonic similarity task performance, did not alter Arc expression. Arc expression in CA3, however, was correlated with task performance on the more difficult discrimination trials across both surgical groups. These observations further support a link between CA3 activity and mnemonic similarity task performance but suggest the reduced input from the entorhinal cortex to the hippocampus, as observed in old age, does not causatively elevate CA3 activity.
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Affiliation(s)
- Tara L. Cooper
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Graduate Program in Biomedical Sciences, Neuroscience Concentration, University of Florida, Gainesville, FL, United States
| | - John J. Thompson
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Sean M. Turner
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Cory Watson
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Katelyn N. Lubke
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Carly N. Logan
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Andrew P. Maurer
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Sara N. Burke
- Department of Neuroscience, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
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19
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Lee H, Wang Z, Tillekeratne A, Lukish N, Puliyadi V, Zeger S, Gallagher M, Knierim JJ. Loss of functional heterogeneity along the CA3 transverse axis in aging. Curr Biol 2022; 32:2681-2693.e4. [PMID: 35597233 PMCID: PMC9233142 DOI: 10.1016/j.cub.2022.04.077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 04/18/2022] [Accepted: 04/26/2022] [Indexed: 01/05/2023]
Abstract
Age-related deficits in pattern separation have been postulated to bias the output of hippocampal memory processing toward pattern completion, which can cause deficits in accurate memory retrieval. Although the CA3 region of the hippocampus is often conceptualized as a homogeneous network involved in pattern completion, growing evidence demonstrates a functional gradient in CA3 along the transverse axis, as pattern-separated outputs (dominant in the more proximal CA3) transition to pattern-completed outputs (dominant in the more distal CA3). We examined the neural representations along the CA3 transverse axis in young (Y), aged memory-unimpaired (AU), and aged memory-impaired (AI) rats when different changes were made to the environment. Functional heterogeneity in CA3 was observed in Y and AU rats when the environmental similarity was high (altered cues or altered environment shapes in the same room), with more orthogonalized representations in proximal CA3 than in distal CA3. In contrast, AI rats showed reduced orthogonalization in proximal CA3 but showed normal (i.e., generalized) representations in distal CA3, with little evidence of a functional gradient. Under experimental conditions when the environmental similarity was low (different rooms), representations in proximal and distal CA3 remapped in all rats, showing that CA3 of AI rats is able to encode distinctive representations for inputs with greater dissimilarity. These experiments support the hypotheses that the age-related bias toward hippocampal pattern completion is due to the loss in AI rats of the normal transition from pattern separation to pattern completion along the CA3 transverse axis.
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Affiliation(s)
- Heekyung Lee
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, 21218,Correspondence: ;
| | - Zitong Wang
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21205
| | - Arjuna Tillekeratne
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, 21218
| | - Nick Lukish
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, 21218
| | - Vyash Puliyadi
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, 21218,Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD
| | - Scott Zeger
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21205
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD,Kavli Neuroscience Discovery Institute, Johns Hopkins University
| | - James J. Knierim
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, 21218,Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD,Kavli Neuroscience Discovery Institute, Johns Hopkins University,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205,Lead Contact,Correspondence: ;
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20
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Hernandez CM, McQuail JA, Ten Eyck TW, Wheeler AR, Labiste CC, Setlow B, Bizon J. GABA B receptors in prelimbic cortex and basolateral amygdala differentially influence intertemporal decision making and decline with age. Neuropharmacology 2022; 209:109001. [PMID: 35189132 DOI: 10.1016/j.neuropharm.2022.109001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/07/2022] [Accepted: 02/15/2022] [Indexed: 11/25/2022]
Abstract
The ability to decide adaptively between immediate vs. delayed gratification (intertemporal choice) is critical for well-being and is associated with a range of factors that influence quality of life. In contrast to young adults, many older adults show enhanced preference for delayed gratification; however, the neural mechanisms underlying this age difference in intertemporal choice are largely un-studied. Changes in signaling through GABAB receptors (GABABRs) mediate several age-associated differences in cognitive processes linked to intertemporal choice. The current study used a rat model to determine how GABABRs in two brain regions known to regulate intertemporal choice (prelimbic cortex; PrL and basolateral amygdala; BLA) contribute to age differences in this form of decision making in male rats. As in humans, aged rats showed enhanced preference for large, delayed over small, immediate rewards during performance in an intertemporal choice task in operant test chambers. Activation of PrL GABABRs via microinfusion of the agonist baclofen increased choice of large, delayed rewards in young adult rats but did not influence choice in aged rats. Conversely, infusion of baclofen into the BLA strongly reduced choice of large, delayed rewards in both young adult and aged rats. Aged rats further showed a significant reduction in expression of GABABR1 subunit isoforms in the prefrontal cortex, a discovery that is consonant with the null effect of intra-PrL baclofen on intertemporal choice in aged rats. In contrast, expression of GABABR subunits was generally conserved with age in the BLA. Jointly, these findings elucidate a role for GABABRs in intertemporal choice and identify fundamental features of brain maturation and aging that mediate an improved ability to delay gratification.
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Affiliation(s)
- Caesar M Hernandez
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA; Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Joseph A McQuail
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA; Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine - Columbia, Columbia, SC, 29208, USA
| | - Tyler W Ten Eyck
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA
| | - Alexa-Rae Wheeler
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA
| | - Chase C Labiste
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA.
| | - Barry Setlow
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA; Department of Psychiatry, University of Florida, Gainesville, FL, 32610, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Jennifer Bizon
- Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
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21
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Jones EAA, Rao A, Zilberter M, Djukic B, Bant JS, Gillespie AK, Koutsodendris N, Nelson M, Yoon SY, Huang K, Yuan H, Gill TM, Huang Y, Frank LM. Dentate gyrus and CA3 GABAergic interneurons bidirectionally modulate signatures of internal and external drive to CA1. Cell Rep 2021; 37:110159. [PMID: 34965435 PMCID: PMC9069800 DOI: 10.1016/j.celrep.2021.110159] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 10/04/2021] [Accepted: 12/01/2021] [Indexed: 01/19/2023] Open
Abstract
Specific classes of GABAergic neurons play specific roles in regulating information processing in the brain. In the hippocampus, two major classes, parvalbumin-expressing (PV+) and somatostatin-expressing (SST+), differentially regulate endogenous firing patterns and target subcellular compartments of principal cells. How these classes regulate the flow of information throughout the hippocampus is poorly understood. We hypothesize that PV+ and SST+ interneurons in the dentate gyrus (DG) and CA3 differentially modulate CA3 patterns of output, thereby altering the influence of CA3 on CA1. We find that while suppressing either interneuron class increases DG and CA3 output, the effects on CA1 were very different. Suppressing PV+ interneurons increases local field potential signatures of coupling from CA3 to CA1 and decreases signatures of coupling from entorhinal cortex to CA1; suppressing SST+ interneurons has the opposite effect. Thus, DG and CA3 PV+ and SST+ interneurons bidirectionally modulate the flow of information through the hippocampal circuit.
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Affiliation(s)
- Emily A. Aery Jones
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Antara Rao
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Misha Zilberter
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Jason S. Bant
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Anna K. Gillespie
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA
| | - Nicole Koutsodendris
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Maxine Nelson
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Seo Yeon Yoon
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Ky Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Heidi Yuan
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Theodore M. Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA,Departments of Neurology and Pathology, University of California, San Francisco, CA 94143, USA,Gladstone Center for Translational Advancement, San Francisco, CA 94158, USA,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
| | - Loren M. Frank
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA,Lead contact,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
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22
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Ionescu-Tucker A, Butler CW, Berchtold NC, Matheos DP, Wood MA, Cotman CW. Exercise Reduces H3K9me3 and Regulates Brain Derived Neurotrophic Factor and GABRA2 in an Age Dependent Manner. Front Aging Neurosci 2021; 13:798297. [PMID: 34970138 PMCID: PMC8712855 DOI: 10.3389/fnagi.2021.798297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/16/2021] [Indexed: 11/29/2022] Open
Abstract
Exercise improves cognition in the aging brain and is a key regulator of neuronal plasticity genes such as BDNF. However, the mechanism by which exercise modifies gene expression continues to be explored. The repressive histone modification H3K9me3 has been shown to impair cognition, reduce synaptic density and decrease BDNF in aged but not young mice. Treatment with ETP69, a selective inhibitor of H3K9me3's catalyzing enzyme (SUV39H1), restores synapses, BDNF and cognitive performance. GABA receptor expression, which modulates BDNF secretion, is also modulated by exercise and H3K9me3. In this study, we examined if exercise and ETP69 regulated neuronal plasticity genes by reducing H3K9me3 at their promoter regions. We further determined the effect of age on H3K9me3 promoter binding and neuronal plasticity gene expression. Exercise and ETP69 decreased H3K9me3 at BDNF promoter VI in aged mice, corresponding with an increase in BDNF VI expression with ETP69. Exercise increased GABRA2 in aged mice while increasing BDNF 1 in young mice, and both exercise and ETP69 reduced GABRA2 in young mice. Overall, H3K9me3 repression at BDNF and GABA receptor promoters decreased with age. Our findings suggest that exercise and SUV39H1 inhibition differentially modulate BDNF and GABRA2 expression in an age dependent manner.
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Affiliation(s)
- Andra Ionescu-Tucker
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Christopher W. Butler
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
| | - Nicole C. Berchtold
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
| | - Dina P. Matheos
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Marcelo A. Wood
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Carl W. Cotman
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
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23
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Differential Retinoic Acid Signaling in the Hippocampus of Aged Rats with and without Memory Impairment. eNeuro 2021; 8:ENEURO.0120-21.2021. [PMID: 34417282 PMCID: PMC8442538 DOI: 10.1523/eneuro.0120-21.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 12/21/2022] Open
Abstract
Retinoic acid (RA), a metabolite of vitamin A, has many physiological functions, and mounting evidence points to important roles in cognition. In vitro experiments indicate that RA is involved in homeostatic synaptic scaling in the hippocampus, which supports overall network stability during learning. It has been previously determined that disrupted RA signaling in the hippocampus causes deterioration of memory, that RA signaling declines with age in brain, and that application of RA reverses this decline. Here, we explore whether RA signaling is altered in an animal model of neurocognitive aging. We used a Morris water maze protocol to study cognitive decline in aged rats, which assesses hippocampus-dependent spatial memory and reveals substantial interindividual differences in aged animals. Aged unimpaired (AU) rats perform on par with young (Y), while aged impaired (AI) animals exhibit spatial memory deficits. We show that the major substrate for RA, retinol binding protein 4 (RBP4), is decreased in AU rats, and retinol cell surface receptor declines with chronological age. Other affected components of RA signaling include selective increases in AI animals in hippocampal synthesis (RALDH1) and catabolism of RA (CYP26B1), RA receptor α, the RA regulated ionotropic glutamate receptor (GluR1), as well as fragile X mental retardation protein (FMRP). The results support the conclusion that, surprisingly, increased RA signaling in the aged hippocampus is associated with poor cognitive outcome.
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24
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Weiler M, Moreno-Castilla P, Starnes HM, Melendez ELR, Stieger KC, Long JM, Rapp PR. Effects of repetitive Transcranial Magnetic Stimulation in aged rats depend on pre-treatment cognitive status: Toward individualized intervention for successful cognitive aging. Brain Stimul 2021; 14:1219-1225. [PMID: 34400378 DOI: 10.1016/j.brs.2021.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 08/02/2021] [Accepted: 08/09/2021] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Repetitive Transcranial Magnetic Stimulation (rTMS) has shown initial promise in combating age-related cognitive decline and dementia. The nature and severity of cognitive aging, however, varies markedly between individuals. OBJECTIVE/HYPOTHESIS We hypothesized that the distinct constellation of brain changes responsible for individual differences in cognitive aging might influence the response to rTMS. METHODS Cognitive effects of rTMS were evaluated using a rat model of cognitive aging in which aged rats are classified as Aged-Impaired (AI) or -Unimpaired (AU) relative to young (Y) according to their performance in the Morris water maze. Several weeks later, following presentation of a sample odor in an olfactory recognition task, rats received either sham (Y, n = 9; AU, n = 8; AI, n = 9) or intermittent Theta Burst Stimulation (Y, n = 8; AU, n = 8; AI, n = 9). Memory was tested 24 h later. RESULTS Recognition memory in the sham and stimulated conditions depended on pre-treatment cognitive status in the aged rats. Y and AU sham rats displayed robust odor recognition, whereas sham-treated AI rats exhibited no retention. In contrast, rTMS treated AI rats showed robust retention, comparable in magnitude to Y, whereas the AU stimulated scored at chance. CONCLUSION Our results are consistent with a perspective that the unique neurobiology associated with variability in cognitive aging modulates the response to rTMS. Protocols with documented efficacy in young adults may have unexpected outcomes in aging or neurodegenerative conditions, requiring individualized approaches.
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Affiliation(s)
- Marina Weiler
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Perla Moreno-Castilla
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Hannah M Starnes
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Edward L R Melendez
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Kevin C Stieger
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Jeffrey M Long
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA
| | - Peter R Rapp
- Neurocognitive Aging Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, Intramural Research Program, USA.
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25
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Memel M, Staffaroni AM, Cobigo Y, Casaletto KB, Fonseca C, Bettcher BM, Yassa MA, Elahi FM, Wolf A, Rosen HJ, Kramer JH. APOE moderates the effect of hippocampal blood flow on memory pattern separation in clinically normal older adults. Hippocampus 2021; 31:845-857. [PMID: 33835624 PMCID: PMC8295213 DOI: 10.1002/hipo.23327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/25/2021] [Accepted: 03/07/2021] [Indexed: 11/10/2022]
Abstract
Pattern separation, the ability to differentiate new information from previously experienced similar information, is highly sensitive to hippocampal structure and function and declines with age. Functional MRI studies have demonstrated hippocampal hyperactivation in older adults compared to young, with greater task-related activation associated with worse pattern separation performance. The current study was designed to determine whether pattern separation was sensitive to differences in task-free hippocampal cerebral blood flow (CBF) in 130 functionally intact older adults. Given prior evidence that apolipoprotein E e4 (APOE e4) status moderates the relationship between CBF and episodic memory, we predicted a stronger negative relationship between hippocampal CBF and pattern separation in APOE e4 carriers. An interaction between APOE group and right hippocampal CBF was present, such that greater right hippocampal CBF was related to better lure discrimination in noncarriers, whereas the effect reversed directionality in e4 carriers. These findings suggest that neurovascular changes in the medial temporal lobe may underlie memory deficits in cognitively normal older adults who are APOE e4 carriers.
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Affiliation(s)
- Molly Memel
- San Francisco VA Medical Center, San Francisco, California
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Adam M. Staffaroni
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Yann Cobigo
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Kaitlin B. Casaletto
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Corrina Fonseca
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Brianne M. Bettcher
- Department of Neurology, University of Colorado Anschutz Medical Campus, CU Alzheimer’s and Cognition Center, Aurora, Colorado
| | - Michael A. Yassa
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and Memory, University of California, Irvine, California
| | - Fanny M. Elahi
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Amy Wolf
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Howard J. Rosen
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Joel H. Kramer
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
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26
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Porges EC, Jensen G, Foster B, Edden RAE, Puts NAJ. The trajectory of cortical GABA across the lifespan, an individual participant data meta-analysis of edited MRS studies. eLife 2021; 10:e62575. [PMID: 34061022 PMCID: PMC8225386 DOI: 10.7554/elife.62575] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 05/30/2021] [Indexed: 01/18/2023] Open
Abstract
γ-Aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the human brain and can be measured with magnetic resonance spectroscopy (MRS). Conflicting accounts report decreases and increases in cortical GABA levels across the lifespan. This incompatibility may be an artifact of the size and age range of the samples utilized in these studies. No single study to date has included the entire lifespan. In this study, eight suitable datasets were integrated to generate a model of the trajectory of frontal GABA estimates (as reported through edited MRS; both expressed as ratios and in institutional units) across the lifespan. Data were fit using both a log-normal curve and a nonparametric spline as regression models using a multi-level Bayesian model utilizing the Stan language. Integrated data show that an asymmetric lifespan trajectory of frontal GABA measures involves an early period of increase, followed by a period of stability during early adulthood, with a gradual decrease during adulthood and aging that is described well by both spline and log-normal models. The information gained will provide a general framework to inform expectations of future studies based on the age of the population being studied.
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Affiliation(s)
- Eric C Porges
- Center for Cognitive Aging and Memory, University of FloridaGainesvilleUnited States
- McKnight Brain Research Foundation, University of FloridaUnited StatesUnited States
- Department of Clinical and Health Psychology, University of FloridaGainesvilleUnited States
| | - Greg Jensen
- Department of Neuroscience, Columbia University Medical CenterNew YorkUnited States
- Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Brent Foster
- Center for Cognitive Aging and Memory, University of FloridaGainesvilleUnited States
- McKnight Brain Research Foundation, University of FloridaUnited StatesUnited States
- Department of Clinical and Health Psychology, University of FloridaGainesvilleUnited States
| | - Richard AE Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of MedicineBaltimoreUnited States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger InstituteBaltimoreUnited States
| | - Nicolaas AJ Puts
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of MedicineBaltimoreUnited States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger InstituteBaltimoreUnited States
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, King’s College LondonLondonUnited Kingdom
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27
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Reid HMO, Chen-Mack N, Snowden T, Christie BR. Understanding Changes in Hippocampal Interneurons Subtypes in the Pathogenesis of Alzheimer's Disease: A Systematic Review. Brain Connect 2021; 11:159-179. [PMID: 33559520 DOI: 10.1089/brain.2020.0879] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background: It is becoming increasingly recognized that there is significant interneuron degeneration in Alzheimer's disease. As the hippocampus is integral for learning and memory, we performed a systematic review of primary literature focused on the relationship between Alzheimer's and hippocampal interneurons. In this study, we summarize the experimental work performed to date and identify opportunities for future experiments. Objectives: This PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-style systematic review seeks to summarize the findings of all accessible research focused on cholecystokinin (CCK), neuropeptide Y (NPY), parvalbumin (PV), and somatostatin (SOM) interneurons in the hippocampal formation. Results: One thousand five hundred ninety-three articles were pulled from PubMed, PsycInfo, and Web of Science, based on three blocks of search terms. There were 45 articles that met all the predetermined inclusion/exclusion criteria. There is strong evidence that PV interneurons are affected early in the disease by toxic amyloid beta (Aβ) fragments; SOM interneurons are affected indirectly while the SOM neuropeptide may act to slowly worsen toxic Aβ fragment accumulation, whereas NPY- and CCK-positive interneurons are affected later in the progression of the disease. Conclusions: Fewer studies have been performed on NPY and CCK interneurons, and there is room for further investigations regarding the role of PV interneurons in Alzheimer's to help resolve contradictory findings. This review found that PV interneurons are affected early in the disease, but only in Alzheimer's precursor protein but not tau models. NPY and CCK interneurons were found to be affected later in the disease, and SOM interneurons vary greatly. Future studies may consider reporting immunohistochemical studies inclusive of either cell location or morphology-as well as marker to give a more robust picture of the disease.
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Affiliation(s)
- Hannah M O Reid
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Nathan Chen-Mack
- Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Victoria, British Columbia, Canada
| | - Taylor Snowden
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Brian R Christie
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Victoria, British Columbia, Canada
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28
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Rao G, Lee H, Gallagher M, Knierim JJ. Decreased investigatory head scanning during exploration in learning-impaired, aged rats. Neurobiol Aging 2021; 98:1-9. [PMID: 33221571 PMCID: PMC8639103 DOI: 10.1016/j.neurobiolaging.2020.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/23/2020] [Accepted: 10/08/2020] [Indexed: 01/04/2023]
Abstract
"Head scanning" is an investigatory behavior that has been linked to spatial exploration and the one-trial formation or strengthening of place cells in the hippocampus. Previous studies have demonstrated that a subset of aged rats with normal spatial learning performance show head scanning rates during a novel, local-global cue-mismatch manipulation that are similar to those of young rats. However, these aged rats demonstrated different patterns of expression of neural activity markers in brain regions associated with spatial learning, perhaps suggesting neural mechanisms that compensate for age-related brain changes. These prior studies did not investigate the head scanning properties of aged rats that had spatial learning impairments. The present study analyzed head scanning behavior in young, aged-unimpaired, and aged-impaired Long Evans rats. Aged-impaired rats performed the head scan behavior at a lower rate than the young rats. These results suggest that decreased attention to spatial landmarks may be a contributing factor to the spatial learning deficits shown by the aged-impaired rats.
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Affiliation(s)
- Geeta Rao
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA.
| | - Heekyung Lee
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - James J Knierim
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA; Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
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29
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Heterogeneity of Age-Related Neural Hyperactivity along the CA3 Transverse Axis. J Neurosci 2021; 41:663-673. [PMID: 33257325 DOI: 10.1523/jneurosci.2405-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/12/2020] [Accepted: 11/19/2020] [Indexed: 02/08/2023] Open
Abstract
Age-related memory deficits are correlated with neural hyperactivity in the CA3 region of the hippocampus. Abnormal CA3 hyperactivity in aged rats has been proposed to contribute to an imbalance between pattern separation and pattern completion, resulting in overly rigid representations. Recent evidence of functional heterogeneity along the CA3 transverse axis suggests that proximal CA3 supports pattern separation while distal CA3 supports pattern completion. It is not known whether age-related CA3 hyperactivity is uniformly represented along the CA3 transverse axis. We examined the firing rates of CA3 neurons from young and aged, male, Long-Evans rats along the CA3 transverse axis. Consistent with prior studies, young CA3 cells showed an increasing gradient in mean firing rate from proximal to distal CA3. However, aged CA3 cells showed an opposite, decreasing trend, in that CA3 cells in aged rats were hyperactive in proximal CA3, but possibly hypoactive in distal CA3, compared with young (Y) rats. We suggest that, in combination with altered inputs from the entorhinal cortex and dentate gyrus (DG), the proximal CA3 region of aged rats may switch from its normal function that reflects the pattern separation output of the DG and instead performs a computation that reflects an abnormal bias toward pattern completion. In parallel, distal CA3 of aged rats may create weaker attractor basins that promote abnormal, bistable representations under certain conditions.SIGNIFICANCE STATEMENT Prior work suggested that age-related CA3 hyperactivity enhances pattern completion, resulting in rigid representations. Implicit in prior studies is the notion that hyperactivity is present throughout a functionally homogeneous CA3 network. However, more recent work has demonstrated functional heterogeneity along the CA3 transverse axis, in that proximal CA3 is involved in pattern separation and distal CA3 is involved in pattern completion. Here, we show that age-related hyperactivity is present only in proximal CA3, with potential hypoactivity in distal CA3. This result provides new insight in the role of CA3 in age-related memory impairments, suggesting that the rigid representations in aging result primarily from dysfunction of computational circuits involving the dentate gyrus (DG) and proximal CA3.
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30
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Popescu IR, Le KQ, Ducote AL, Li JE, Leland AE, Mostany R. Increased intrinsic excitability and decreased synaptic inhibition in aged somatosensory cortex pyramidal neurons. Neurobiol Aging 2020; 98:88-98. [PMID: 33249377 DOI: 10.1016/j.neurobiolaging.2020.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/02/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
Abstract
Sensorimotor performance declines during advanced age, partially due to deficits in somatosensory acuity. Cortical receptive field expansion contributes to somatosensory deficits, suggesting increased excitability or decreased inhibition in primary somatosensory cortex (S1) pyramidal neurons. To ascertain changes in excitability and inhibition, we measured both properties in neurons from vibrissal S1 in brain slices from young and aged mice. Because adapting and non-adapting neurons-the principal pyramidal types in layer 5 (L5)-differ in intrinsic properties and inhibitory inputs, we determined age-dependent changes according to neuron type. We found an age-dependent increase in intrinsic excitability in adapting neurons, caused by a decrease in action potential threshold. Surprisingly, in non-adapting neurons we found both an increase in excitability caused by increased input resistance, and a decrease in synaptic inhibition. Spike frequency adaptation, already small in non-adapting neurons, was further reduced by aging, whereas sag, a manifestation of Ih, was increased. Therefore, aging caused both decreased inhibition and increased intrinsic excitability, but these effects were specific to pyramidal neuron type.
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Affiliation(s)
- Ion R Popescu
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA.
| | - Kathy Q Le
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Alexis L Ducote
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Jennifer E Li
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | | | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
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Dickey B, Madhu LN, Shetty AK. Gulf War Illness: Mechanisms Underlying Brain Dysfunction and Promising Therapeutic Strategies. Pharmacol Ther 2020; 220:107716. [PMID: 33164782 DOI: 10.1016/j.pharmthera.2020.107716] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022]
Abstract
Gulf War Illness (GWI), a chronic multisymptom health problem, afflicts ~30% of veterans served in the first GW. Impaired brain function is among the most significant symptoms of GWI, which is typified by persistent cognitive and mood impairments, concentration problems, headaches, chronic fatigue, and musculoskeletal pain. This review aims to discuss findings from animal prototypes and veterans with GWI on mechanisms underlying its pathophysiology and emerging therapeutic strategies for alleviating brain dysfunction in GWI. Animal model studies have linked brain impairments to incessantly elevated oxidative stress, chronic inflammation, inhibitory interneuron loss, altered lipid metabolism and peroxisomes, mitochondrial dysfunction, modified expression of genes relevant to cognitive function, and waned hippocampal neurogenesis. Furthermore, the involvement of systemic alterations such as the increased intensity of reactive oxygen species and proinflammatory cytokines in the blood, transformed gut microbiome, and activation of the adaptive immune response have received consideration. Investigations in veterans have suggested that brain dysfunction in GWI is linked to chronic activation of the executive control network, impaired functional connectivity, altered blood flow, persistent inflammation, and changes in miRNA levels. Lack of protective alleles from Class II HLA genes, the altered concentration of phospholipid species and proinflammatory factors in the circulating blood have also been suggested as other aiding factors. While some drugs or combination therapies have shown promise for alleviating symptoms in clinical trials, larger double-blind, placebo-controlled trials are needed to validate such findings. Based on improvements seen in animal models of GWI, several antioxidants and anti-inflammatory compounds are currently being tested in clinical trials. However, reliable blood biomarkers that facilitate an appropriate screening of veterans for brain pathology need to be discovered. A liquid biopsy approach involving analysis of brain-derived extracellular vesicles in the blood appears efficient for discerning the extent of neuropathology both before and during clinical trials.
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Affiliation(s)
- Brandon Dickey
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA; Texas A&M University Health Science Center College of Medicine, Temple, TX, USA
| | - Leelavathi N Madhu
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA.
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Bi D, Wen L, Wu Z, Shen Y. GABAergic dysfunction in excitatory and inhibitory (E/I) imbalance drives the pathogenesis of Alzheimer's disease. Alzheimers Dement 2020; 16:1312-1329. [PMID: 32543726 DOI: 10.1002/alz.12088] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/28/2020] [Accepted: 02/10/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To propose a new hypothesis that GABAergic dysfunction in excitatory and inhibitory (E/I) imbalance drives the pathogenesis of Alzheimer's disease (AD). BACKGROUND Synaptic dysfunction and E/I imbalance emerge decades before the appearance of cognitive decline in AD patients, which contribute to neurodegeneration. Initially, E/I imbalance was thought to occur first, due to dysfunction of the glutamatergic and cholinergic systems. However, new evidence has demonstrated that the GABAergic system, the counterpart of E/I balance and the major inhibitory neurotransmitter system in the central nervous system, is altered enormously and that this contributes to E/I imbalance and further AD pathogenesis. NEW HYPOTHESIS Alterations to the GABAergic system, induced by multiple AD pathogenic or risk factors, contribute to E/I imbalance and AD pathogenesis. MAJOR CHALLENGES FOR THE HYPOTHESIS This GABAergic hypothesis accounts for many critical questions and common challenges confronting a new hypothesis of AD pathogenesis. More specifically, it explains why amyloid beta (Aβ), β-secretase (BACE1), apolipoprotein E4 gene (APOE ε4), hyperactive glia cells, contributes to AD pathogenesis and why age and sex are the risk factors of AD. GABAergic dysfunction promotes the spread of Aβ pathology throughout the AD brain and associated cognitive impairments, and the induction of dysfunction induced by these varied risk factors shares this common neurobiology leading to E/I imbalance. In turn, some of these factors exacerbate GABAergic dysfunction and E/I imbalance. Moreover, the GABAergic system modulates various brain functions and thus, the GABAergic hypothesis accounts for nonamnestic manifestations. Furthermore, corrections of E/I balance through manipulation of GABAergic functions have shown positive outcomes in preclinical and clinical studies, suggesting the potential of the GABAergic system as a therapeutic target in AD. LINKAGE TO OTHER MAJOR THEORIES Dysfunction of the GABAergic system is induced by multiple critical signaling pathways, which include the existing major theories of AD pathogenesis, such as the Aβ and neuroinflammation hypotheses. In a new perspective, this GABAergic hypothesis accounts for the E/I imbalance and related excitotoxicity, which contribute to cognitive decline and AD pathogenesis. Therefore, the GABAergic system could be a key target to restore, at least partially, the E/I balance and cognitive function in AD patients.
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Affiliation(s)
- Danlei Bi
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Institute on Aging and Brain Disorders, University of Sciences and Technology of China, Hefei, China.,Neurodegenerative Disease Research Center, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Lang Wen
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Institute on Aging and Brain Disorders, University of Sciences and Technology of China, Hefei, China.,Neurodegenerative Disease Research Center, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Zujun Wu
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Institute on Aging and Brain Disorders, University of Sciences and Technology of China, Hefei, China.,Neurodegenerative Disease Research Center, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yong Shen
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Institute on Aging and Brain Disorders, University of Sciences and Technology of China, Hefei, China.,Neurodegenerative Disease Research Center, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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Chakraborty A, Banerjee S, Mukherjee B, Poddar MK. Calorie restriction improves aging-induced impairment of cognitive function in relation to deregulation of corticosterone status and brain regional GABA system. Mech Ageing Dev 2020; 189:111248. [PMID: 32339520 DOI: 10.1016/j.mad.2020.111248] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/16/2020] [Accepted: 04/05/2020] [Indexed: 12/21/2022]
Abstract
Aging is known to affect adversely the corticosterone status and the brain function including cognition. Calorie restricted (CR) diet has been found to improve brain aging. The objective of the present investigation is to study the effect of short-term CR diet without any food deprivation on aging-induced impairment of cognitive function in relation to the corticosterone status and the brain regional GABA system. The result showed that aging-induced deregulation of the brain regional GABA system, increase in plasma and adrenal corticosterone levels and cognitive impairment were attenuated with short-term CR diet supplementation for consecutive 1 and 2 months to the aged (18 and 24 months) rats. But in young rats (4 months) consumption of the same CR diet under similar conditions reversibly affected those above-mentioned parameters. These results, thus suggest that (a) aging down-regulates brain regional GABA system with an up-regulation of corticosterone status and impairment of cognitive function, (b) CR diet consumption improves this aging-induced deregulation of brain regional GABA system, corticosterone status, and cognitive function, (c) these attenuating effects of CR diet are greater with a longer period of consumption but (d) CR diet consumption is harmful to young rats as observed in those parameters.
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Affiliation(s)
- Apala Chakraborty
- Department of Pharmaceutical Technology, Jadavpur University, 188, Raja S.C. Mallick Road, Kolkata, 700032, India
| | - Soumyabrata Banerjee
- Department of Pharmaceutical Technology, Jadavpur University, 188, Raja S.C. Mallick Road, Kolkata, 700032, India
| | - Biswajit Mukherjee
- Department of Pharmaceutical Technology, Jadavpur University, 188, Raja S.C. Mallick Road, Kolkata, 700032, India
| | - Mrinal Kanti Poddar
- Department of Pharmaceutical Technology, Jadavpur University, 188, Raja S.C. Mallick Road, Kolkata, 700032, India.
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Koh MT, Branch A, Haberman R, Gallagher M. Significance of inhibitory recruitment in aging with preserved cognition: limiting gamma-aminobutyric acid type A α5 function produces memory impairment. Neurobiol Aging 2020; 91:1-4. [PMID: 32240868 DOI: 10.1016/j.neurobiolaging.2020.02.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/30/2019] [Accepted: 02/22/2020] [Indexed: 01/27/2023]
Abstract
Numerous aging studies have identified a shift in the excitatory/inhibitory (E/I) balance with heightened hippocampal neural activity associated with age-related memory impairment across species, including rats, monkeys, and humans. Neurobiological investigations directed at the hippocampal formation have demonstrated that unimpaired aged rats performing on par with young adult rats in a spatial memory task exhibit gene expression profiles, mechanisms for plasticity, and altered circuit/network function, which are distinct from younger rats. Particularly striking is a convergence of observational evidence that aged unimpaired rats augment recruitment of mechanisms associated with neural inhibition, a finding that may represent an adaptive homeostatic adjustment necessary to maintain neural plasticity and memory function in aging. In this study, we test the effect of limiting inhibition via administration of TB21007, a negative allosteric modulator of the alpha 5 subtype of gamma-aminobutyric acid type A α5 receptor, on a radial arm maze assessment of memory function. Impaired memory performance produced by this intervention in otherwise high-performing aged rats supports an adaptive role for gamma-aminobutyric acid in the functional maintenance of intact cognition in aging.
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Affiliation(s)
- Ming Teng Koh
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Audrey Branch
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Rebecca Haberman
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
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Pipová Kokošová N, Kisková T, Vilhanová K, Štafuriková A, Jendželovský R, Račeková E, Šmajda B. Melatonin mitigates hippocampal and cognitive impairments caused by prenatal irradiation. Eur J Neurosci 2020; 52:3575-3594. [PMID: 31985866 DOI: 10.1111/ejn.14687] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 01/10/2020] [Accepted: 01/17/2020] [Indexed: 12/11/2022]
Abstract
Formation of new neurons and glial cells in the brain is taking place in mammals not only during prenatal embryogenesis but also during adult life. As an enhancer of oxidative stress, ionizing radiation represents a potent inhibitor of neurogenesis and gliogenesis in the brain. It is known that the pineal hormone melatonin is a potent free radical scavenger and counteracts inflammation and apoptosis in brain injuries. The aim of our study was to establish the effects of melatonin on cells in the hippocampus and selected forms of behaviour in prenatally irradiated rats. The male progeny of irradiated (1 Gy of gamma rays; n = 38) and sham-irradiated mothers (n = 19), aged 3 weeks or 2 months, were used in the experiment. Melatonin was administered daily in drinking water (4 mg/kg b. w.) to a subset of animals from each age group. Prenatal irradiation markedly suppressed proliferative activity in the dentate gyrus in both age groups. Melatonin significantly increased the number of proliferative BrdU-positive cells in hilus of young irradiated animals, and the number of mature NeuN-positive neurons in hilus and granular cell layer of the dentate gyrus in these rats and in CA1 region of adult irradiated rats. Moreover, melatonin significantly improved the spatial memory impaired by irradiation, assessed in Morris water maze. A significant correlation between the number of proliferative cells and cognitive performances was found, too. Our study indicates that melatonin may decrease the loss of hippocampal neurons in the CA1 region and improve cognitive abilities after irradiation.
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Affiliation(s)
- Natália Pipová Kokošová
- Department of Animal Physiology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
| | - Terézia Kisková
- Department of Animal Physiology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
| | - Katarína Vilhanová
- Department of Animal Physiology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
| | - Andrea Štafuriková
- Department of Animal Physiology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
| | - Rastislav Jendželovský
- Department of Cell Biology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
| | - Enikő Račeková
- Institute of Neurobiology, Biomedical Research Center, Slovak Academy of Sciences, Košice, Slovak Republic
| | - Beňadik Šmajda
- Department of Animal Physiology, Faculty of Science, Institute of Biology and Ecology, P. J. Šafárik University in Košice, Košice, Slovak Republic
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Gray DT, Barnes CA. Experiments in macaque monkeys provide critical insights into age-associated changes in cognitive and sensory function. Proc Natl Acad Sci U S A 2019; 116:26247-26254. [PMID: 31871147 PMCID: PMC6936691 DOI: 10.1073/pnas.1902279116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The use of animal models in brain aging research has led to numerous fundamental insights into the neurobiological processes that underlie changes in brain function associated with normative aging. Macaque monkeys have become the predominant nonhuman primate model system in brain aging research due to their striking similarities to humans in their behavioral capacities, sensory processing abilities, and brain architecture. Recent public concern about nonhuman primate research has made it imperative to attempt to clearly articulate the potential benefits to human health that this model enables. The present review will highlight how nonhuman primates provide a critical bridge between experiments conducted in rodents and development of therapeutics for humans. Several studies discussed here exemplify how nonhuman primate research has enriched our understanding of cognitive and sensory decline in the aging brain, as well as how this work has been important for translating mechanistic implications derived from experiments conducted in rodents to human brain aging research.
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Affiliation(s)
- Daniel T. Gray
- Division of Neural System, Memory & Aging, The University of Arizona, Tucson, AZ 85724
- Evelyn F. McKnight Brain Institute, The University of Arizona, Tucson, AZ 85724
| | - Carol A. Barnes
- Division of Neural System, Memory & Aging, The University of Arizona, Tucson, AZ 85724
- Evelyn F. McKnight Brain Institute, The University of Arizona, Tucson, AZ 85724
- Department of Psychology, The University of Arizona, Tucson, AZ 85724
- Department of Neurology, The University of Arizona, Tucson, AZ 85724
- Department of Neuroscience, The University of Arizona, Tucson, AZ 85724
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Reduced cognitive performance in aged rats correlates with increased excitation/inhibition ratio in the dentate gyrus in response to lateral entorhinal input. Neurobiol Aging 2019; 82:120-127. [DOI: 10.1016/j.neurobiolaging.2019.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 11/18/2022]
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Duda P, Wójcicka O, Wiśniewski JR, Rakus D. Global quantitative TPA-based proteomics of mouse brain structures reveals significant alterations in expression of proteins involved in neuronal plasticity during aging. Aging (Albany NY) 2019; 10:1682-1697. [PMID: 30026405 PMCID: PMC6075443 DOI: 10.18632/aging.101501] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 07/15/2018] [Indexed: 01/17/2023]
Abstract
Aging is believed to be the result of alterations of protein expression and accumulation of changes in biomolecules. Although there are numerous reports demonstrating changes in protein expression in brain during aging, only few of them describe global changes at the protein level. Here, we present the deepest quantitative proteomic analysis of three brain regions, hippocampus, cortex and cerebellum, in mice aged 1 or 12 months, using the total protein approach technique. In all the brain regions, both in young and middle-aged animals, we quantitatively measured over 5,200 proteins. We found that although the total protein expression in middle-aged brain structures is practically unaffected by aging, there are significant differences between young and middle-aged mice in the expression of some receptors and signaling cascade proteins proven to be significant for learning and memory formation. Our analysis demonstrates that the hippocampus is the most variable structure during natural aging and that the first symptoms of weakening of neuronal plasticity may be observed on protein level in middle-aged animals.
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Affiliation(s)
- Przemysław Duda
- Department of Molecular Physiology and Neurobiology, University of Wroclaw, Wroclaw 50-137, Poland
| | - Olga Wójcicka
- Department of Molecular Physiology and Neurobiology, University of Wroclaw, Wroclaw 50-137, Poland
| | - Jacek R Wiśniewski
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried 82152, Germany
| | - Dariusz Rakus
- Department of Molecular Physiology and Neurobiology, University of Wroclaw, Wroclaw 50-137, Poland
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Hernandez AR, Hernandez CM, Truckenbrod LM, Campos KT, McQuail JA, Bizon JL, Burke SN. Age and Ketogenic Diet Have Dissociable Effects on Synapse-Related Gene Expression Between Hippocampal Subregions. Front Aging Neurosci 2019; 11:239. [PMID: 31607897 PMCID: PMC6755342 DOI: 10.3389/fnagi.2019.00239] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/19/2019] [Indexed: 01/01/2023] Open
Abstract
As the number of individuals living beyond the age of 65 is rapidly increasing, so is the need to develop strategies to combat the age-related cognitive decline that may threaten independent living. Although the link between altered neuronal signaling and age-related cognitive impairments is not completely understood, it is evident that declining cognitive abilities are at least partially due to synaptic dysfunction. Aging is accompanied by well-documented changes in both excitatory and inhibitory synaptic signaling across species. Age-related synaptic alterations are not uniform across the brain, however, with different regions showing unique patterns of vulnerability in advanced age. In the hippocampus, increased activity within the CA3 subregion has been observed across species, and this can be reversed with anti-epileptic medication. In contrast to CA3, the dentate gyrus shows reduced activity with age and declining metabolic activity. Ketogenic diets have been shown to decrease seizure incidence and severity in epilepsy, improve metabolic function in diabetes type II, and improve cognitive function in aged rats. This link between neuronal activity and metabolism suggests that metabolic interventions may be able to ameliorate synaptic signaling deficits accompanying advanced age. We therefore investigated the ability of a dietary regimen capable of inducing nutritional ketosis and improving cognition to alter synapse-related gene expression across the dentate gyrus, CA3 and CA1 subregions of the hippocampus. Following 12 weeks of a ketogenic or calorie-matched standard diet, RTq-PCR was used to quantify expression levels of excitatory and inhibitory synaptic signaling genes within CA1, CA3 and dentate gyrus. While there were no age or diet-related changes in CA1 gene expression, expression levels were significantly altered within CA3 by age and within the dentate gyrus by diet for several genes involved in presynaptic glutamate regulation and postsynaptic excitation and plasticity. These data demonstrate subregion-specific alterations in synaptic signaling with age and the potential for a ketogenic diet to alter these processes in dissociable ways across different brain structures that are uniquely vulnerable in older animals.
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Affiliation(s)
- Abbi R. Hernandez
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
| | - Caesar M. Hernandez
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
| | - Leah M. Truckenbrod
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
| | - Keila T. Campos
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
| | - Joseph A. McQuail
- Department of Physiology, Pharmacology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, United States
| | - Jennifer L. Bizon
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
| | - Sara N. Burke
- Department of Neurosciences, University of Florida, Gainesville, FL, United States
- Institute on Aging, University of Florida, Gainesville, FL, United States
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Gao T, Liu Y, Zhao Z, Luo Y, Wang L, Wang Y, Yin Y. L-655,708 Does not Prevent Isoflurane-induced Memory Deficits in Old Mice. Transl Neurosci 2019; 10:180-186. [PMID: 31410301 PMCID: PMC6689210 DOI: 10.1515/tnsci-2019-0032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/21/2019] [Indexed: 01/07/2023] Open
Abstract
Background General anesthesia and increasing age are two main risk factors for postoperative cognitive dysfunction (POCD). Effective agents for the prevention or treatment of POCD are urgently needed. L-655,708, an inverse agonist of α5 subunit-containing γ-aminobutyric acid subtype A (α5GABAA) receptors, can prevent anesthesia-induced memory deficits in young animals. However, there is a lack of evidence of its efficacy in old animals. Methodology Young (3- to 5-month-old) and old (18- to 20-month-old) mice were given an inhalation of 1.33% isoflurane for 1 hour and their associative memory was evaluated 24 hours after anesthesia using fear-conditioning tests (FCTs). To evaluate the effect of L-655,708, mice received intraperitoneal injections of L-655,708 (0.7 mg/kg) or vehicle 30 minutes before anesthesia. Results Old mice exhibited impaired memory and lower hippocampal α5GABAA levels than young mice under physiological conditions. Pre-injections of L-655,708 significantly alleviated isoflurane-induced memory decline in young mice, but not in old mice. Conclusions L-655,708 is not as effective for the prevention of POCD in old mice as it is in young mice. The use of inverse agonists of α5GABAA in preventing POCD in old patients should be carefully considered.
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Affiliation(s)
- Teng Gao
- Department of Anesthesiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China
| | - Yue Liu
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Zifang Zhao
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Yuan Luo
- State Key Laboratory of Toxicology and Medical Countermeasures, Academy of Military Medical Sciences, Beijing, 100850, China
| | - Lifang Wang
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Yongan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Academy of Military Medical Sciences, Beijing, 100850, China
| | - Yiqing Yin
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, 100029, China
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Myrum C, Rossi SL, Perez EJ, Rapp PR. Cortical network dynamics are coupled with cognitive aging in rats. Hippocampus 2019; 29:1165-1177. [PMID: 31334577 DOI: 10.1002/hipo.23130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/23/2019] [Accepted: 06/05/2019] [Indexed: 12/27/2022]
Abstract
Changes in neuronal network activity and increased interindividual variability in memory are among the most consistent features of growing older. Here, we examined the relationship between these hallmarks of aging. Young and aged rats were trained on a water maze task where aged individuals reliably display an increased range of spatial memory capacities relative to young. Two weeks later, neuronal activity was induced pharmacologically with a low dose of pilocarpine and control animals received vehicle. Activity levels were proxied by quantifying the immediate early gene products Arc and c-Fos. While no relationship was observed between basal, resting activity, and individual differences in spatial memory in any brain region, pilocarpine-induced marker expression was tightly coupled with memory in all areas of the prefrontal cortex (PFC) and hippocampus examined. The nature of this association, however, differed across regions and in relation to age-related cognitive outcome. Specifically, in the medial PFC, induced activity was greatest in aged rats with cognitive impairment and correlated with water maze performance across all subjects. In the hippocampus, the range of induced marker expression was comparable between groups and similarly coupled with memory in both impaired and unimpaired aged rats. Together the findings highlight that the dynamic range of neural network activity across multiple brain regions is a critical component of neurocognitive aging.
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Affiliation(s)
- Craig Myrum
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, Maryland
| | - Sharyn L Rossi
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, Maryland
| | - Evelyn J Perez
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, Maryland
| | - Peter R Rapp
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, Maryland
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Haberman RP, Monasterio A, Branch A, Gallagher M. Aged rats with intact memory show distinctive recruitment in cortical regions relative to young adults in a cue mismatch task. Behav Neurosci 2019; 133:537-544. [PMID: 31246080 DOI: 10.1037/bne0000332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Similar to elderly humans, aged Long-Evans rats exhibit individual differences in performance on tasks that critically depend on the medial temporal lobe memory system. Although reduced memory performance is common, close to half of aged rats in this outbred rodent population perform within the range of young subjects, exhibiting a stable behavioral phenotype that may signal a resilience to memory decline. Increasing evidence from research on aging in the Long-Evans study population supports the existence of adaptive neural change rather than avoidance of detrimental effects of aging on the brain, indicating a malleability of brain function over the life span that may preserve optimal function. Augmenting prior work that centered on hippocampal function, the current study extends investigation to cortical regions functionally interconnected with the hippocampal formation, including medial temporal lobe cortices and posterior components of the default mode network. In response to an environmental manipulation that creates a mismatch in the expected cue orientation, aged rats with preserved memory show greater activation across an extended network of cortical regions as measured by immediate early gene expression. In contrast, young subjects, behaviorally similar to the aged rats in this study, show a more limited cortical response. This distinctive cortical recruitment in aged unimpaired rats, set against a background of comparable activation across hippocampal subregions, may represent adaptive cortical recruitment consistent with evidence in human studies of neurocognitive aging. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Ryan L, Hay M, Huentelman MJ, Duarte A, Rundek T, Levin B, Soldan A, Pettigrew C, Mehl MR, Barnes CA. Precision Aging: Applying Precision Medicine to the Field of Cognitive Aging. Front Aging Neurosci 2019; 11:128. [PMID: 31231204 PMCID: PMC6568195 DOI: 10.3389/fnagi.2019.00128] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/16/2019] [Indexed: 12/13/2022] Open
Abstract
The current "one size fits all" approach to our cognitive aging population is not adequate to close the gap between cognitive health span and lifespan. In this review article, we present a novel model for understanding, preventing, and treating age-related cognitive impairment (ARCI) based on concepts borrowed from precision medicine. We will discuss how multiple risk factors can be classified into risk categories because of their interrelatedness in real life, the genetic variants that increase sensitivity to, or ameliorate, risk for ARCI, and the brain drivers or common mechanisms mediating brain aging. Rather than providing a definitive model of risk for ARCI and cognitive decline, the Precision Aging model is meant as a starting point to guide future research. To that end, after briefly discussing key risk categories, genetic risks, and brain drivers, we conclude with a discussion of steps that must be taken to move the field forward.
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Affiliation(s)
- Lee Ryan
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Meredith Hay
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Matt J. Huentelman
- Neurobehavioral Research Unit, Division of Neurological Disorders, Translational Genomics Research Institute (TGen), Phoenix, AZ, United States
| | - Audrey Duarte
- Center for Advanced Brain Imaging, School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| | - Tatjana Rundek
- Clinical and Translational Research Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Bonnie Levin
- Neuropsychology Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Anja Soldan
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Corinne Pettigrew
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Matthias R. Mehl
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Carol A. Barnes
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
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Márquez F, Yassa MA. Neuroimaging Biomarkers for Alzheimer's Disease. Mol Neurodegener 2019; 14:21. [PMID: 31174557 PMCID: PMC6555939 DOI: 10.1186/s13024-019-0325-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 05/28/2019] [Indexed: 12/11/2022] Open
Abstract
Currently, over five million Americans suffer with Alzheimer's disease (AD). In the absence of a cure, this number could increase to 13.8 million by 2050. A critical goal of biomedical research is to establish indicators of AD during the preclinical stage (i.e. biomarkers) allowing for early diagnosis and intervention. Numerous advances have been made in developing biomarkers for AD using neuroimaging approaches. These approaches offer tremendous versatility in terms of targeting distinct age-related and pathophysiological mechanisms such as structural decline (e.g. volumetry, cortical thinning), functional decline (e.g. fMRI activity, network correlations), connectivity decline (e.g. diffusion anisotropy), and pathological aggregates (e.g. amyloid and tau PET). In this review, we survey the state of the literature on neuroimaging approaches to developing novel biomarkers for the amnestic form of AD, with an emphasis on combining approaches into multimodal biomarkers. We also discuss emerging methods including imaging epigenetics, neuroinflammation, and synaptic integrity using PET tracers. Finally, we review the complementary information that neuroimaging biomarkers provide, which highlights the potential utility of composite biomarkers as suitable outcome measures for proof-of-concept clinical trials with experimental therapeutics.
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Affiliation(s)
- Freddie Márquez
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, CA, 92697, USA.
| | - Michael A Yassa
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, CA, 92697, USA.
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HDAC3-Mediated Repression of the Nr4a Family Contributes to Age-Related Impairments in Long-Term Memory. J Neurosci 2019; 39:4999-5009. [PMID: 31000586 DOI: 10.1523/jneurosci.2799-18.2019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/27/2019] [Accepted: 04/14/2019] [Indexed: 02/06/2023] Open
Abstract
Aging is accompanied by cognitive deficits, including impairments in long-term memory formation. Understanding the molecular mechanisms that support preserved cognitive function in aged animals is a critical step toward identifying novel therapeutic targets that could improve memory in aging individuals. One potential mechanism is the Nr4a family of genes, a group of CREB-dependent nuclear orphan receptors that have previously been shown to be important for hippocampal memory formation. Here, using a cross-species approach, we tested the role of Nr4a1 and Nr4a2 in age-related memory impairments. Using a rat model designed to identify individual differences in age-related memory impairments, we first identified Nr4a2 as a key gene that fails to be induced by learning in cognitively impaired male aged rats. Next, using a mouse model that allows for genetic manipulations, we determined that histone deacetylase 3 (HDAC3) negatively regulates Nr4a2 in the aged male and female hippocampus. Finally, we show that overexpression of Nr4a1, Nr4a2, or both transcripts in the male mouse dorsal hippocampus can ameliorate age-related impairments in object location memory. Together, our results suggest that Nr4a2 may be a key mechanism that promotes preserved cognitive function in old age, with HDAC3-mediated repression of Nr4a2 contributing to age-related cognitive decline. More broadly, these results indicate that therapeutic strategies to promote Nr4a gene expression or function may be an effective strategy to improve cognitive function in old age.SIGNIFICANCE STATEMENT Aging is accompanied by memory impairments, although there is a great deal of variability in the severity of these impairments. Identifying molecular mechanisms that promote preserved memory or participate in cognitive reserve in old age is important to develop strategies that promote healthy cognitive aging. Here, we show that learning-induced expression of the CREB-regulated nuclear receptor gene Nr4a2 is selectively impaired in aged rats with memory impairments. Further, we show that Nr4a2 is regulated by histone deacetylase HDAC3 in the aged mouse hippocampus. Finally, we demonstrate that hippocampal overexpression of either Nr4a2 or its family member, Nr4a1, can ameliorate age-related memory impairments. This suggests that promoting Nr4a expression may be a novel strategy to improve memory in aging individuals.
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Johnson SA, Turner SM, Lubke KN, Cooper TL, Fertal KE, Bizon JL, Maurer AP, Burke SN. Experience-Dependent Effects of Muscimol-Induced Hippocampal Excitation on Mnemonic Discrimination. Front Syst Neurosci 2019; 12:72. [PMID: 30687032 PMCID: PMC6335355 DOI: 10.3389/fnsys.2018.00072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022] Open
Abstract
Memory requires similar episodes with overlapping features to be represented distinctly, a process that is disrupted in many clinical conditions as well as normal aging. Data from humans have linked this ability to activity in hippocampal CA3 and dentate gyrus (DG). While animal models have shown the perirhinal cortex is critical for disambiguating similar stimuli, hippocampal activity has not been causally linked to discrimination abilities. The goal of the current study was to determine how disrupting CA3/DG activity would impact performance on a rodent mnemonic discrimination task. Rats were surgically implanted with bilateral guide cannulae targeting dorsal CA3/DG. In Experiment 1, the effect of intra-hippocampal muscimol on target-lure discrimination was assessed within subjects in randomized blocks. Muscimol initially impaired discrimination across all levels of target-lure similarity, but performance improved on subsequent test blocks irrespective of stimulus similarity and infusion condition. To clarify these results, Experiment 2 examined whether prior experience with objects influenced the effect of muscimol on target-lure discrimination. Rats that received vehicle infusions in a first test block, followed by muscimol in a second block, did not show discrimination impairments for target-lure pairs of any similarity. In contrast, rats that received muscimol infusions in the first test block were impaired across all levels of target-lure similarity. Following discrimination tests, rats from Experiment 2 were trained on a spatial alternation task. Muscimol infusions increased the number of spatial errors made, relative to vehicle infusions, confirming that muscimol remained effective in disrupting behavioral performance. At the conclusion of behavioral experiments, fluorescence in situ hybridization for the immediate-early genes Arc and Homer1a was used to determine the proportion of neurons active following muscimol infusion. Contrary to expectations, muscimol increased neural activity in DG. An additional experiment was carried out to quantify neural activity in naïve rats that received an intra-hippocampal infusion of vehicle or muscimol. Results confirmed that muscimol led to DG excitation, likely through its actions on interneuron populations in hilar and molecular layers of DG and consequent disinhibition of principal cells. Taken together, our results suggest disruption of coordinated neural activity across the hippocampus impairs mnemonic discrimination when lure stimuli are novel.
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Affiliation(s)
- Sarah A Johnson
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Sean M Turner
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States
| | - Katelyn N Lubke
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Tara L Cooper
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Kaeli E Fertal
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Jennifer L Bizon
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Andrew P Maurer
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sara N Burke
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Institute on Aging, University of Florida, Gainesville, FL, United States
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Branch A, Monasterio A, Blair G, Knierim JJ, Gallagher M, Haberman RP. Aged rats with preserved memory dynamically recruit hippocampal inhibition in a local/global cue mismatch environment. Neurobiol Aging 2019; 76:151-161. [PMID: 30716540 DOI: 10.1016/j.neurobiolaging.2018.12.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/14/2018] [Accepted: 12/27/2018] [Indexed: 10/27/2022]
Abstract
Similar to elderly humans, aged outbred Long-Evans rats exhibit individual differences in memory abilities, including a subset of aged rats that maintain memory function on par with young adults. Such individuals provide a basis for investigating mechanisms of resilience to age-related decline. The present study examined hippocampal gene expression in young adults and aged rats with preserved memory function under behavioral task conditions well established for assessing information processing central to the formation of episodic memory. Although behavioral measures and hippocampal gene induction associated with neural activity and synaptic plasticity were similar across age groups, a marker for inhibitory interneuron function in the hippocampal formation was distinctively increased only in aged rats but not in young adults. Because heightened hippocampal neural activity is associated with age-related memory impairment across species, including rats, monkeys, and humans, this finding may represent an adaptive homeostatic adjustment necessary to maintain neural plasticity and memory function in aging.
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Affiliation(s)
- Audrey Branch
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Amy Monasterio
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Grace Blair
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - James J Knierim
- Department of Neuroscience and Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Rebecca P Haberman
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
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Role of gamma-amino-butyric acid in the dorsal anterior cingulate in age-associated changes in cognition. Neuropsychopharmacology 2018; 43:2285-2291. [PMID: 30050047 PMCID: PMC6135795 DOI: 10.1038/s41386-018-0134-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/13/2018] [Accepted: 06/18/2018] [Indexed: 11/08/2022]
Abstract
GABAergic mechanisms have been shown to contribute to cognitive aging in animal models, but there is currently limited in vivo evidence to support this relationship in humans. It is also unclear whether aging is associated with changes in GABA levels measured with proton magnetic resonance spectroscopy (MRS). Spectral-editing MRS at 3 T was used to measure GABA in the dorsal anterior cingulate cortex (dACC) for a large sample of healthy volunteers (N = 229) aged 18-55. In a subset of 171 participants, age effects on several cognitive tasks were studied. We formally tested whether the MRS measures mediated the relationship between age and cognition. Robust associations of age with performance were found for the Wisconsin Card Sorting Test ([WCST], p < 0.0001). Age was also significantly associated with declining levels of GABA in the dACC (p < 0.001), and GABA levels significantly predicted WCST performance (p < 0.0004). Mediation analysis revealed that GABA in the dACC mediated the effect of age on WCST performance (p < 0.01). Other metabolites were similarly associated with age, but only GABA and creatine levels were significantly associated with WCST performance. No association with age or cognitive performance was found in a frontal white matter control region in a subset of participants. The association of GABA with WCST performance was not related to the amount of brain atrophy associated with aging as measured by the proportion of CSF, gray, and white matter in the MRS voxel. These results implicate GABAergic and possibly energetic metabolism in the dACC as mechanisms of age effects in executive function.
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A separable two-dimensional random field model of binary response data from multi-day behavioral experiments. J Neurosci Methods 2018; 307:175-187. [PMID: 29679704 DOI: 10.1016/j.jneumeth.2018.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 03/13/2018] [Accepted: 04/12/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND The study of learning in populations of subjects can provide insights into the changes that occur in the brain with aging, drug intervention, and psychiatric disease. NEW METHOD We introduce a separable two-dimensional (2D) random field (RF) model for analyzing binary response data acquired during the learning of object-reward associations across multiple days. The method can quantify the variability of performance within a day and across days, and can capture abrupt changes in learning. RESULTS We apply the method to data from young and aged macaque monkeys performing a reversal-learning task. The method provides an estimate of performance within a day for each age group, and a learning rate across days for each monkey. We find that, as a group, the older monkeys require more trials to learn the object discriminations than do the young monkeys, and that the cognitive flexibility of the younger group is higher. We also use the model estimates of performance as features for clustering the monkeys into two groups. The clustering results in two groups that, for the most part, coincide with those formed by the age groups. Simulation studies suggest that clustering captures inter-individual differences in performance levels. COMPARISON WITH EXISTING METHOD(S) In comparison with generalized linear models, this method is better able to capture the inherent two-dimensional nature of the data and find between group differences. CONCLUSIONS Applied to binary response data from groups of individuals performing multi-day behavioral experiments, the model discriminates between-group differences and identifies subgroups.
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Prévôt TD, Viollet C, Epelbaum J, Dominguez G, Béracochéa D, Guillou JL. sst 2-receptor gene deletion exacerbates chronic stress-induced deficits: Consequences for emotional and cognitive ageing. Prog Neuropsychopharmacol Biol Psychiatry 2018; 86:390-400. [PMID: 29409919 DOI: 10.1016/j.pnpbp.2018.01.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/17/2018] [Accepted: 01/30/2018] [Indexed: 02/07/2023]
Abstract
This study investigated whether sst2 gene deletion interacts with age and chronic stress exposure to produce exacerbated emotional and cognitive ageing. Middle-aged (10-12 month) sst2 knockout (sst2KO) and wild-type (WT) mice underwent an unpredictable chronic mild stress (UCMS) procedure for 6 weeks or no stress for control groups. This was followed by a battery of tests to assess emotional and cognitive functions and neuroendocrine status (CORT level). A re-evaluation was performed 6 months later (i.e. with 18-month-old mice). UCMS reproduced neuroendocrine and behavioral features of stress-related disorders such as elevated circulating CORT levels, physical deteriorations, increased anxiety- and depressive-like behaviors and working memory impairments. sst2KO mice displayed behavioral alterations which were similar to stressed WT and exhibited exacerbated changes following UCMS exposure. The evaluations performed in the older mice showed significant long-term effects of UCMS exposure. Old sst2KO mice previously exposed to UCMS exhibited spatial learning and memory accuracy impairments and high levels of anxiety-like behaviors which drastically added to the effects of normal ageing. Spatial abilities and emotionality scores (mean z-scores) measured both at the UCMS outcome and 6 months later were correlated with the initially measured CORT levels in middle-age. The present findings indicate that the deletion of the sst2 receptor gene produces chronic hypercorticosteronemia and exacerbates sensitivity to stressors which over time, have consequences on ageing brain function processes.
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Affiliation(s)
- Thomas Damien Prévôt
- Université de Bordeaux, Pessac, France; Centre National de la Recherche Scientifique, UMR 5287, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Pessac, France
| | - Cécile Viollet
- Inserm, UMR 894, Center for Psychiatry & Neuroscience, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jacques Epelbaum
- Inserm, UMR 894, Center for Psychiatry & Neuroscience, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; UMR 7179 CNRS MNHN - MECADEV, 91800 Brunoy, France
| | - Gaëlle Dominguez
- Centre National de la Recherche Scientifique, UMR 5287, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Pessac, France
| | - Daniel Béracochéa
- Université de Bordeaux, Pessac, France; Centre National de la Recherche Scientifique, UMR 5287, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Pessac, France
| | - Jean-Louis Guillou
- Université de Bordeaux, Pessac, France; Centre National de la Recherche Scientifique, UMR 5287, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Pessac, France.
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