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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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2
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Shin P, Pian Q, Ishikawa H, Hamanaka G, Mandeville ET, Guo S, Fu B, Alfadhel M, Allu SR, Şencan-Eğilmez I, Li B, Ran C, Vinogradov SA, Ayata C, Lo E, Arai K, Devor A, Sakadžić S. Aerobic exercise reverses aging-induced depth-dependent decline in cerebral microcirculation. eLife 2023; 12:e86329. [PMID: 37402178 PMCID: PMC10319437 DOI: 10.7554/elife.86329] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/16/2023] [Indexed: 07/06/2023] Open
Abstract
Aging is a major risk factor for cognitive impairment. Aerobic exercise benefits brain function and may promote cognitive health in older adults. However, underlying biological mechanisms across cerebral gray and white matter are poorly understood. Selective vulnerability of the white matter to small vessel disease and a link between white matter health and cognitive function suggests a potential role for responses in deep cerebral microcirculation. Here, we tested whether aerobic exercise modulates cerebral microcirculatory changes induced by aging. To this end, we carried out a comprehensive quantitative examination of changes in cerebral microvascular physiology in cortical gray and subcortical white matter in mice (3-6 vs. 19-21 months old), and asked whether and how exercise may rescue age-induced deficits. In the sedentary group, aging caused a more severe decline in cerebral microvascular perfusion and oxygenation in deep (infragranular) cortical layers and subcortical white matter compared with superficial (supragranular) cortical layers. Five months of voluntary aerobic exercise partly renormalized microvascular perfusion and oxygenation in aged mice in a depth-dependent manner, and brought these spatial distributions closer to those of young adult sedentary mice. These microcirculatory effects were accompanied by an improvement in cognitive function. Our work demonstrates the selective vulnerability of the deep cortex and subcortical white matter to aging-induced decline in microcirculation, as well as the responsiveness of these regions to aerobic exercise.
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Affiliation(s)
- Paul Shin
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Qi Pian
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Gen Hamanaka
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Emiri T Mandeville
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Shuzhen Guo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Buyin Fu
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Mohammed Alfadhel
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Bioengineering, Northeastern University, Boston, United States
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Ikbal Şencan-Eğilmez
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Biophotonics Research Center, Mallinckrodt Institute of Radiology, Department of Radiology, Washington University School of Medicine, St. Louis, United States
| | - Baoqiang Li
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Chongzhao Ran
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Eng Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Anna Devor
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Biomedical Engineering, Boston University, Boston, United States
| | - Sava Sakadžić
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
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3
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Cerasuolo M, Papa M, Colangelo AM, Rizzo MR. Alzheimer’s Disease from the Amyloidogenic Theory to the Puzzling Crossroads between Vascular, Metabolic and Energetic Maladaptive Plasticity. Biomedicines 2023; 11:biomedicines11030861. [PMID: 36979840 PMCID: PMC10045635 DOI: 10.3390/biomedicines11030861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/06/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Alzheimer’s disease (AD) is a progressive and degenerative disease producing the most common type of dementia worldwide. The main pathogenetic hypothesis in recent decades has been the well-known amyloidogenic hypothesis based on the involvement of two proteins in AD pathogenesis: amyloid β (Aβ) and tau. Amyloid deposition reported in all AD patients is nowadays considered an independent risk factor for cognitive decline. Vascular damage and blood–brain barrier (BBB) failure in AD is considered a pivotal mechanism for brain injury, with increased deposition of both immunoglobulins and fibrin. Furthermore, BBB dysfunction could be an early sign of cognitive decline and the early stages of clinical AD. Vascular damage generates hypoperfusion and relative hypoxia in areas with high energy demand. Long-term hypoxia and the accumulation within the brain parenchyma of neurotoxic molecules could be seeds of a self-sustaining pathological progression. Cellular dysfunction comprises all the elements of the neurovascular unit (NVU) and neuronal loss, which could be the result of energy failure and mitochondrial impairment. Brain glucose metabolism is compromised, showing a specific region distribution. This energy deficit worsens throughout aging. Mild cognitive impairment has been reported to be associated with a glucose deficit in the entorhinal cortex and in the parietal lobes. The current aim is to understand the complex interactions between amyloid β (Aβ) and tau and elements of the BBB and NVU in the brain. This new approach aimed at the study of metabolic mechanisms and energy insufficiency due to mitochondrial impairment would allow us to define therapies aimed at predicting and slowing down the progression of AD.
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Affiliation(s)
- Michele Cerasuolo
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
| | - Michele Papa
- Laboratory of Neuronal Networks Morphology and System Biology, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
- SYSBIO Centre of Systems Biology ISBE-IT, 20126 Milan, Italy
- Correspondence:
| | - Anna Maria Colangelo
- SYSBIO Centre of Systems Biology ISBE-IT, 20126 Milan, Italy
- Laboratory of Neuroscience “R. Levi-Montalcini”, Department of Biotechnology and Biosciences, NeuroMI Milan Center for Neuroscience, University of Milano-Bicocca, 20126 Milano, Italy
| | - Maria Rosaria Rizzo
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
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Bickel MA, Csik B, Gulej R, Ungvari A, Nyul-Toth A, Conley SM. Cell non-autonomous regulation of cerebrovascular aging processes by the somatotropic axis. Front Endocrinol (Lausanne) 2023; 14:1087053. [PMID: 36755922 PMCID: PMC9900125 DOI: 10.3389/fendo.2023.1087053] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/04/2023] [Indexed: 01/24/2023] Open
Abstract
Age-related cerebrovascular pathologies, ranging from cerebromicrovascular functional and structural alterations to large vessel atherosclerosis, promote the genesis of vascular cognitive impairment and dementia (VCID) and exacerbate Alzheimer's disease. Recent advances in geroscience, including results from studies on heterochronic parabiosis models, reinforce the hypothesis that cell non-autonomous mechanisms play a key role in regulating cerebrovascular aging processes. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) exert multifaceted vasoprotective effects and production of both hormones is significantly reduced in aging. This brief overview focuses on the role of age-related GH/IGF-1 deficiency in the development of cerebrovascular pathologies and VCID. It explores the mechanistic links among alterations in the somatotropic axis, specific macrovascular and microvascular pathologies (including capillary rarefaction, microhemorrhages, impaired endothelial regulation of cerebral blood flow, disruption of the blood brain barrier, decreased neurovascular coupling, and atherogenesis) and cognitive impairment. Improved understanding of cell non-autonomous mechanisms of vascular aging is crucial to identify targets for intervention to promote cerebrovascular and brain health in older adults.
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Affiliation(s)
- Marisa A. Bickel
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Boglarka Csik
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Rafal Gulej
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Anna Ungvari
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Adam Nyul-Toth
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Department of Public Health, Semmelweis University, Budapest, Hungary
- Institute of Biophysics, Biological Research Centre, Eötvös Lorand Research Network (ELKH), Szeged, Hungary
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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5
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Ueno H, Takahashi Y, Murakami S, Wani K, Miyazaki T, Matsumoto Y, Okamoto M, Ishihara T. Component-Specific Reduction in Perineuronal Nets in Senescence-Accelerated Mouse Strains. IBRO Neurosci Rep 2023. [DOI: 10.1016/j.ibneur.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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6
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Su Z, Yan J, Ji H, Liu M, Zhang X, Li X, Yuan Y. Time-frequency cross-coupling between cortical low-frequency neuronal calcium oscillations and blood oxygen metabolism evoked by ultrasound stimulation. Cereb Cortex 2022; 33:4665-4676. [PMID: 36137570 DOI: 10.1093/cercor/bhac370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/14/2022] Open
Abstract
Low-intensity transcranial ultrasound stimulation (TUS) can modulate the coupling of high-frequency (160-200 Hz) neural oscillations and cerebral blood oxygen metabolism (BOM); however, the correlation of low-frequency (0-2 Hz) neural oscillations with BOM in temporal and frequency domains under TUS remains unclear. To address this, we monitored the TUS-evoked neuronal calcium oscillations and BOM simultaneously in the mouse visual cortex by using multimodal optical imaging with a high spatiotemporal resolution. We demonstrated that TUS can significantly increase the intensity of the neuronal calcium oscillations and BOM; the peak value, peak time, and duration of calcium oscillations are functionally related to stimulation duration; TUS does not significantly increase the neurovascular coupling strength between calcium oscillations and BOM in the temporal domain; the time differences of the energy peaks between TUS-induced calcium oscillations and BOM depend on their spectral ranges; the frequency differences of the energy peaks between TUS-induced calcium oscillations and BOM depend on their time ranges; and TUS can significantly change the phase of calcium oscillations and BOM from uniform distribution to a more concentrated region. In conclusion, ultrasound stimulation can evoke the time-frequency cross-coupling between the cortical low-frequency neuronal calcium oscillations and BOM in mouse.
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Affiliation(s)
- Zhaocheng Su
- School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China.,Key Laboratory of Intelligent Rehabilitation and Neuromodulation of Hebei Province, Yanshan University, Qinhuangdao 066004, China
| | - Jiaqing Yan
- College of Electrical and Control Engineering, North China University of Technology, Beijing 100041, China
| | - Hui Ji
- Department of Neurology, Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna 1090, Austria
| | - Xiangjian Zhang
- Department of Neurology, Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Xiaoli Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
| | - Yi Yuan
- School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China.,Key Laboratory of Intelligent Rehabilitation and Neuromodulation of Hebei Province, Yanshan University, Qinhuangdao 066004, China
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7
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Lin RL, Frazier HN, Anderson KL, Case SL, Ghoweri AO, Thibault O. Sensitivity of the S1 neuronal calcium network to insulin and Bay-K 8644 in vivo: Relationship to gait, motivation, and aging processes. Aging Cell 2022; 21:e13661. [PMID: 35717599 PMCID: PMC9282843 DOI: 10.1111/acel.13661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/10/2022] [Accepted: 06/05/2022] [Indexed: 01/25/2023] Open
Abstract
Neuronal hippocampal Ca2+ dysregulation is a critical component of cognitive decline in brain aging and Alzheimer's disease and is suggested to impact communication and excitability through the activation of a larger after hyperpolarization. However, few studies have tested for the presence of Ca2+ dysregulation in vivo, how it manifests, and whether it impacts network function across hundreds of neurons. Here, we tested for neuronal Ca2+ network dysregulation in vivo in the primary somatosensory cortex (S1) of anesthetized young and aged male Fisher 344 rats using single‐cell resolution techniques. Because S1 is involved in sensory discrimination and proprioception, we tested for alterations in ambulatory performance in the aged animal and investigated two potential pathways underlying these central aging‐ and Ca2+‐dependent changes. Compared to young, aged animals displayed increased overall activity and connectivity of the network as well as decreased ambulatory speed. In aged animals, intranasal insulin (INI) increased network synchronicity and ambulatory speed. Importantly, in young animals, delivery of the L‐type voltage‐gated Ca2+ channel modifier Bay‐K 8644 altered network properties, replicating some of the changes seen in the older animal. These results suggest that hippocampal Ca2+ dysregulation may be generalizable to other areas, such as S1, and might engage modalities that are associated with locomotor stability and motivation to ambulate. Further, given the safety profile of INI in the clinic and the evidence presented here showing that this central dysregulation is sensitive to insulin, we suggest that these processes can be targeted to potentially increase motivation and coordination while also reducing fall frequency with age.
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Affiliation(s)
- Ruei-Lung Lin
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Hilaree N Frazier
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Katie L Anderson
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Sami L Case
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Adam O Ghoweri
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Olivier Thibault
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
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8
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Turner MP, Zhao Y, Abdelkarim D, Liu P, Spence JS, Hutchison JL, Sivakolundu DK, Thomas BP, Hubbard NA, Xu C, Taneja K, Lu H, Rypma B. Altered linear coupling between stimulus-evoked blood flow and oxygen metabolism in the aging human brain. Cereb Cortex 2022; 33:135-151. [PMID: 35388407 PMCID: PMC9758587 DOI: 10.1093/cercor/bhac057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 11/14/2022] Open
Abstract
Neural-vascular coupling (NVC) is the process by which oxygen and nutrients are delivered to metabolically active neurons by blood vessels. Murine models of NVC disruption have revealed its critical role in healthy neural function. We hypothesized that, in humans, aging exerts detrimental effects upon the integrity of the neural-glial-vascular system that underlies NVC. To test this hypothesis, calibrated functional magnetic resonance imaging (cfMRI) was used to characterize age-related changes in cerebral blood flow (CBF) and oxygen metabolism during visual cortex stimulation. Thirty-three younger and 27 older participants underwent cfMRI scanning during both an attention-controlled visual stimulation task and a hypercapnia paradigm used to calibrate the blood-oxygen-level-dependent signal. Measurement of stimulus-evoked blood flow and oxygen metabolism permitted calculation of the NVC ratio to assess the integrity of neural-vascular communication. Consistent with our hypothesis, we observed monotonic NVC ratio increases with increasing visual stimulation frequency in younger adults but not in older adults. Age-related changes in stimulus-evoked cerebrovascular and neurometabolic signal could not fully explain this disruption; increases in stimulus-evoked neurometabolic activity elicited corresponding increases in stimulus-evoked CBF in younger but not in older adults. These results implicate age-related, demand-dependent failures of the neural-glial-vascular structures that comprise the NVC system.
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Affiliation(s)
- Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Center for BrainHealth, University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Yuguang Zhao
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Center for BrainHealth, University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Dema Abdelkarim
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Center for BrainHealth, University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Peiying Liu
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Jeffrey S Spence
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Center for BrainHealth, University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Joanna L Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Center for BrainHealth, University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Dinesh K Sivakolundu
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA,Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Binu P Thomas
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Nicholas A Hubbard
- Department of Psychology, Center for Brain, Biology, and Behavior, University of Nebraska, Lincoln, NE 68588, USA
| | - Cuimei Xu
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Kamil Taneja
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Hanzhang Lu
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Bart Rypma
- Corresponding author: School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA.
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9
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Brain Metabolic Alterations in Alzheimer's Disease. Int J Mol Sci 2022; 23:ijms23073785. [PMID: 35409145 PMCID: PMC8998942 DOI: 10.3390/ijms23073785] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 01/27/2023] Open
Abstract
The brain is one of the most energy-consuming organs in the body. Satisfying such energy demand requires compartmentalized, cell-specific metabolic processes, known to be complementary and intimately coupled. Thus, the brain relies on thoroughly orchestrated energy-obtaining agents, processes and molecular features, such as the neurovascular unit, the astrocyte-neuron metabolic coupling, and the cellular distribution of energy substrate transporters. Importantly, early features of the aging process are determined by the progressive perturbation of certain processes responsible for adequate brain energy supply, resulting in brain hypometabolism. These age-related brain energy alterations are further worsened during the prodromal stages of neurodegenerative diseases, namely Alzheimer's disease (AD), preceding the onset of clinical symptoms, and are anatomically and functionally associated with the loss of cognitive abilities. Here, we focus on concrete neuroenergetic features such as the brain's fueling by glucose and lactate, the transporters and vascular system guaranteeing its supply, and the metabolic interactions between astrocytes and neurons, and on its neurodegenerative-related disruption. We sought to review the principles underlying the metabolic dimension of healthy and AD brains, and suggest that the integration of these concepts in the preventive, diagnostic and treatment strategies for AD is key to improving the precision of these interventions.
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10
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Miller LR, Tarantini S, Nyúl-Tóth Á, Johnston MP, Martin T, Bullen EC, Bickel MA, Sonntag WE, Yabluchanskiy A, Csiszar A, Ungvari ZI, Elliott MH, Conley SM. Increased Susceptibility to Cerebral Microhemorrhages Is Associated With Imaging Signs of Microvascular Degeneration in the Retina in an Insulin-Like Growth Factor 1 Deficient Mouse Model of Accelerated Aging. Front Aging Neurosci 2022; 14:788296. [PMID: 35356301 PMCID: PMC8959924 DOI: 10.3389/fnagi.2022.788296] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 01/31/2022] [Indexed: 01/21/2023] Open
Abstract
Age-related cerebrovascular defects contribute to vascular cognitive impairment and dementia (VCID) as well as other forms of dementia. There has been great interest in developing biomarkers and other tools for studying cerebrovascular disease using more easily accessible tissues outside the brain such as the retina. Decreased circulating insulin-like growth factor 1 (IGF-1) levels in aging are thought to contribute to the development of cerebrovascular impairment, a hypothesis that has been supported by the use of IGF-1 deficient animal models. Here we evaluate vascular and other retinal phenotypes in animals with circulating IGF-1 deficiency and ask whether the retina mimics common age-related vascular changes in the brain such as the development of microhemorrhages. Using a hypertension-induced model, we confirm that IGF-1 deficient mice exhibited worsened microhemorrhages than controls. The retinas of IGF-1 deficient animals do not exhibit microhemorrhages but do exhibit signs of vascular damage and retinal stress such as patterns of vascular constriction and Müller cell activation. These signs of retinal stress are not accompanied by retinal degeneration or impaired neuronal function. These data suggest that the role of IGF-1 in the retina is complex, and while IGF-1 deficiency leads to vascular defects in both the brain and the retina, not all brain pathologies are evident in the retina.
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Affiliation(s)
- Lauren R. Miller
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Stephenson Cancer Center, University of Oklahoma, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Morgan P. Johnston
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Teryn Martin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Elizabeth C. Bullen
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Marisa A. Bickel
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - William E. Sonntag
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Zoltan I. Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Michael H. Elliott
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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11
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Effects of aging on protein expression in mice brain microvessels: ROS scavengers, mRNA/protein stability, glycolytic enzymes, mitochondrial complexes, and basement membrane components. GeroScience 2021; 44:371-388. [PMID: 34708300 PMCID: PMC8811117 DOI: 10.1007/s11357-021-00468-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/23/2021] [Indexed: 12/25/2022] Open
Abstract
Differentially expressed (DE) proteins in the cortical microvessels (MVs) of young, middle-aged, and old male and female mice were evaluated using discovery-based proteomics analysis (> 4,200 quantified proteins/group). Most DE proteins (> 90%) showed no significant differences between the sexes; however, some significant DE proteins showing sexual differences in MVs decreased from young (8.3%), to middle-aged (3.7%), to old (0.5%) mice. Therefore, we combined male and female data for age-dependent comparisons but noted sex differences for examination. Key proteins involved in the oxidative stress response, mRNA or protein stability, basement membrane (BM) composition, aerobic glycolysis, and mitochondrial function were significantly altered with aging. Relative abundance of superoxide dismutase-1/-2, catalase and thioredoxin were reduced with aging. Proteins participating in either mRNA degradation or pre-mRNA splicing were significantly increased in old mice MVs, whereas protein stabilizing proteins decreased. Glycolytic proteins were not affected in middle age, but the relative abundance of these proteins decreased in MVs of old mice. Although most of the 41 examined proteins composing mitochondrial complexes I–V were reduced in old mice, six of these proteins showed a significant reduction in middle-aged mice, but the relative abundance increased in fourteen proteins. Nidogen, collagen, and laminin family members as well as perlecan showed differing patterns during aging, indicating BM reorganization starting in middle age. We suggest that increased oxidative stress during aging leads to adverse protein profile changes of brain cortical MVs that affect mRNA/protein stability, BM integrity, and ATP synthesis capacity.
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12
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István L, Czakó C, Élő Á, Mihály Z, Sótonyi P, Varga A, Ungvári Z, Csiszár A, Yabluchanskiy A, Conley S, Csipő T, Lipecz Á, Kovács I, Nagy ZZ. Imaging retinal microvascular manifestations of carotid artery disease in older adults: from diagnosis of ocular complications to understanding microvascular contributions to cognitive impairment. GeroScience 2021; 43:1703-1723. [PMID: 34100219 PMCID: PMC8492863 DOI: 10.1007/s11357-021-00392-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023] Open
Abstract
Carotid artery stenosis (CAS) is a consequence of systemic atherosclerotic disease affecting the aging populations of the Western world. CAS is frequently associated with cognitive impairment. However, the mechanisms contributing to the development of vascular cognitive impairment (VCI) associated with CAS are multifaceted and not fully understood. In addition to embolization and decreased blood flow due to the atherosclerotic lesion in the carotid artery, microcirculatory dysfunction in the cerebral circulation also plays a critical role in CAS-related VCI. To better understand the microvascular contributions to cognitive decline associated with CAS and evaluate microvascular protective effects of therapeutic interventions, it is essential to examine the structural and functional changes of the microvessels in the central nervous system (CNS). However, there are some limitations of in vivo brain vascular imaging modalities. The retinal microvasculature provides a unique opportunity to study pathogenesis of cerebral small vessel disease and VCI, because the cerebral circulation and the retinal circulation share similar anatomy, physiology and embryology. Similar microvascular pathologies may manifest in the brain and the retina, thus ocular examination can be used as a noninvasive screening tool to investigate pathological changes in the CNS associated with CAS. In this review, ocular signs of CAS and the retinal manifestations of CAS-associated microvascular dysfunction are discussed. The advantages and limitation of methods that are capable of imaging the ocular circulation (including funduscopy, fluorescein angiography, Doppler sonography, optical coherence tomography [OCT] and optical coherence tomography angiography [OCTA]) are discussed. The potential use of dynamic retinal vessel analysis (DVA), which allows for direct visualization of neurovascular coupling responses in the CNS, for understanding microvascular contributions to cognitive decline in CAS patients is also considered.
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Affiliation(s)
- Lilla István
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary
| | - Cecilia Czakó
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary
| | - Ágnes Élő
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary
| | - Zsuzsanna Mihály
- Department of Vascular & Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Péter Sótonyi
- Department of Vascular & Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Andrea Varga
- Department of Vascular & Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Zoltán Ungvári
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Anna Csiszár
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Andriy Yabluchanskiy
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shannon Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tamás Csipő
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Ágnes Lipecz
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Ophthalmology, Josa Andras Hospital, Nyiregyhaza, Hungary
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary.
- Department of Ophthalmology, Weill Cornell Medical College, New York City, NY, USA.
- Department of Clinical Ophtalmology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary.
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, 39 Mária Street, 1085, Budapest, Hungary
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13
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Zhao Y, Liu P, Turner MP, Abdelkarim D, Lu H, Rypma B. The neural-vascular basis of age-related processing speed decline. Psychophysiology 2021; 58:e13845. [PMID: 34115388 DOI: 10.1111/psyp.13845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022]
Abstract
Most studies examining neurocognitive aging are based on the blood-oxygen level-dependent signal obtained during functional magnetic resonance imaging (fMRI). The physiological basis of this signal is neural-vascular coupling, the process by which neurons signal cerebrovasculature to dilate in response to an increase in active neural metabolism due to stimulation. These fMRI studies of aging rely on the hemodynamic equivalence assumption that this process is not disrupted by physiologic deterioration associated with aging. Studies of neural-vascular coupling challenge this assumption and show that neural-vascular coupling is closely related to cognition. In this review, we put forward a theory of processing speed decline in aging and how it is related to age-related neural-vascular coupling changes based on the results of studies elucidating the relationships between cognition, cerebrovascular dynamics, and aging.
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Affiliation(s)
- Yuguang Zhao
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Peiying Liu
- School of Medicine, Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Monroe P Turner
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Dema Abdelkarim
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Hanzhang Lu
- School of Medicine, Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
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14
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Mächler P, Broggini T, Mateo C, Thunemann M, Fomin-Thunemann N, Doran PR, Sencan I, Kilic K, Desjardins M, Uhlirova H, Yaseen MA, Boas DA, Linninger AA, Vergassola M, Yu X, Lewis LD, Polimeni JR, Rosen BR, Sakadžić S, Buxton RB, Lauritzen M, Kleinfeld D, Devor A. A Suite of Neurophotonic Tools to Underpin the Contribution of Internal Brain States in fMRI. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021; 18:100273. [PMID: 33959688 PMCID: PMC8095678 DOI: 10.1016/j.cobme.2021.100273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Recent developments in optical microscopy, applicable for large-scale and longitudinal imaging of cortical activity in behaving animals, open unprecedented opportunities to gain a deeper understanding of neurovascular and neurometabolic coupling during different brain states. Future studies will leverage these tools to deliver foundational knowledge about brain state-dependent regulation of cerebral blood flow and metabolism as well as regulation as a function of brain maturation and aging. This knowledge is of critical importance to interpret hemodynamic signals observed with functional magnetic resonance imaging (fMRI).
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Affiliation(s)
- Philipp Mächler
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Thomas Broggini
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Celine Mateo
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Martin Thunemann
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | | | - Patrick R. Doran
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Ikbal Sencan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Kivilcim Kilic
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Michèle Desjardins
- Département de Physique, de Génie Physique et d’Optique, Université Laval, Québec, QC G1V 0A6, Canada
| | - Hana Uhlirova
- Institute of Scientific Instruments of the Czech Academy of Science, Brno, Czech Republic
| | - Mohammad A. Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Department of Bioengineering, Northeastern University, Boston, MA 02115, USA
| | - David A. Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Andreas A. Linninger
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Massimo Vergassola
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
- Département de Physique de l’Ecole Normale Supérieure, 75005 Paris, France
| | - Xin Yu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Laura D. Lewis
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Jonathan R. Polimeni
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Bruce R. Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Richard B. Buxton
- Department of Radiology, University of California San Diego, La Jolla, CA 92037, USA
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N 2200, Denmark
- Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup 2600, Denmark
| | - David Kleinfeld
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
- Section on Neurobiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Anna Devor
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
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15
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The aging mouse brain: cognition, connectivity and calcium. Cell Calcium 2021; 94:102358. [PMID: 33517250 DOI: 10.1016/j.ceca.2021.102358] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 02/08/2023]
Abstract
Aging is a complex process that differentially impacts multiple cognitive, sensory, neuronal and molecular processes. Technological innovations now allow for parallel investigation of neuronal circuit function, structure and molecular composition in the brain of awake behaving adult mice. Thus, mice have become a critical tool to better understand how aging impacts the brain. However, a more granular systems-based approach, which considers the impact of age on key features relating to neural processing, is required. Here, we review evidence probing the impact of age on the mouse brain. We focus on a range of processes relating to neuronal function, including cognitive abilities, sensory systems, synaptic plasticity and calcium regulation. Across many systems, we find evidence for prominent age-related dysregulation even before 12 months of age, suggesting that emerging age-related alterations can manifest by late adulthood. However, we also find reports suggesting that some processes are remarkably resilient to aging. The evidence suggests that aging does not drive a parallel, linear dysregulation of all systems, but instead impacts some processes earlier, and more severely, than others. We propose that capturing the more fine-scale emerging features of age-related vulnerability and resilience may provide better opportunities for the rejuvenation of the aged brain.
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16
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Gotti GC, Kikhia M, Wuntke V, Hasam-Henderson LA, Wu B, Geiger JRP, Kovacs R. In situ labeling of non-accommodating interneurons based on metabolic rates. Redox Biol 2020; 38:101798. [PMID: 33285412 PMCID: PMC7724199 DOI: 10.1016/j.redox.2020.101798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 11/25/2022] Open
Abstract
Maintaining high frequency firing of narrow action potentials puts a large metabolic load on fast spiking (FS), perisomatic-inhibitory interneurons compared to their slow-spiking, dendrite targeting counterparts. Although the relationship of action potential (AP) firing and metabolism is firmly established, there is no single method to differentiate interneurons in situ based on their firing properties. In this study, we explore a novel strategy to easily identify the metabolically active FS cells among different classes of interneurons. We found that the oxidation of the fluorescent free radical marker 2,7-dichlorodihydrofluorescein (H2DCF) preferentially occurs in interneurons both in slice cultures and acute brain slices. Despite their morphological heterogeneity, almost all DCF-positive (DCF+) neurons belonged to the cluster of non-accommodating FS interneurons. Furthermore, all FS interneurons expressing parvalbumin (PV) both in slice cultures and in acute slices from tdTomato-PVCre transgenic mice were also DCF+. However, only half of the recorded DCF + cells were also PV+, indicating that H2DCF-oxidation occurs in different interneuron classes characterized by non-accomodating AP-firing. Comprehensively enhancing spontaneous neuronal activity led to mitochondrial oxidation of DCF in pyramidal cells as well as interneurons, suggesting that the apparent selectivity towards interneurons represents differences in the underlying metabolic load. While radical-scavenging, inhibition of APs or NO-synthesis, and iron chelation had no effect on the staining pattern, exposure to the complex-I inhibitor, rotenone, prevented interneuronal DCF accumulation. We conclude that H2DCF oxidation is independent of free radicals but correlates with the intensive oxidative energy metabolism and high mitochondrial mass in interneurons sharing the non-accommodating FS phenotype. Fast spiking non-adapting interneurons preferentially oxidize and accumulate H2DCF. Labeling of interneurons correlates with mitochondrial mass and energy metabolism. Free radical formation does not contribute to DCF-labeling of interneurons.
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Affiliation(s)
- G C Gotti
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany
| | - M Kikhia
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany
| | - V Wuntke
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany
| | - L A Hasam-Henderson
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany
| | - B Wu
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany; Institute of Neuroinformatics, University of Zurich - Irchel, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - J R P Geiger
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany
| | - R Kovacs
- Institut für Neurophysiologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Charité Platz 1, 10117, Berlin, Germany.
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17
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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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18
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Verkhratsky A, Augusto-Oliveira M, Pivoriūnas A, Popov A, Brazhe A, Semyanov A. Astroglial asthenia and loss of function, rather than reactivity, contribute to the ageing of the brain. Pflugers Arch 2020; 473:753-774. [PMID: 32979108 DOI: 10.1007/s00424-020-02465-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/05/2020] [Accepted: 09/09/2020] [Indexed: 12/13/2022]
Abstract
Astroglia represent a class of heterogeneous, in form and function, cells known as astrocytes, which provide for homoeostasis and defence of the central nervous system (CNS). Ageing is associated with morphological and functional remodelling of astrocytes with a prevalence of morphological atrophy and loss of function. In particular, ageing is associated with (i) decrease in astroglial synaptic coverage, (ii) deficits in glutamate and potassium clearance, (iii) reduced astroglial synthesis of synaptogenic factors such as cholesterol, (iv) decrease in aquaporin 4 channels in astroglial endfeet with subsequent decline in the glymphatic clearance, (v) decrease in astroglial metabolic support through the lactate shuttle, (vi) dwindling adult neurogenesis resulting from diminished proliferative capacity of radial stem astrocytes, (vii) decline in the astroglial-vascular coupling and deficient blood-brain barrier and (viii) decrease in astroglial ability to mount reactive astrogliosis. Decrease in reactive capabilities of astroglia are associated with rise of age-dependent neurodegenerative diseases. Astroglial morphology and function can be influenced and improved by lifestyle interventions such as intellectual engagement, social interactions, physical exercise, caloric restriction and healthy diet. These modifications of lifestyle are paramount for cognitive longevity.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain. .,Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, 66075-110, Brazil
| | - Augustas Pivoriūnas
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania
| | - Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997. .,Sechenov First Moscow State Medical University, Moscow, Russia.
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19
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Cunnane SC, Trushina E, Morland C, Prigione A, Casadesus G, Andrews ZB, Beal MF, Bergersen LH, Brinton RD, de la Monte S, Eckert A, Harvey J, Jeggo R, Jhamandas JH, Kann O, la Cour CM, Martin WF, Mithieux G, Moreira PI, Murphy MP, Nave KA, Nuriel T, Oliet SHR, Saudou F, Mattson MP, Swerdlow RH, Millan MJ. Brain energy rescue: an emerging therapeutic concept for neurodegenerative disorders of ageing. Nat Rev Drug Discov 2020; 19:609-633. [PMID: 32709961 PMCID: PMC7948516 DOI: 10.1038/s41573-020-0072-x] [Citation(s) in RCA: 443] [Impact Index Per Article: 110.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2020] [Indexed: 12/11/2022]
Abstract
The brain requires a continuous supply of energy in the form of ATP, most of which is produced from glucose by oxidative phosphorylation in mitochondria, complemented by aerobic glycolysis in the cytoplasm. When glucose levels are limited, ketone bodies generated in the liver and lactate derived from exercising skeletal muscle can also become important energy substrates for the brain. In neurodegenerative disorders of ageing, brain glucose metabolism deteriorates in a progressive, region-specific and disease-specific manner - a problem that is best characterized in Alzheimer disease, where it begins presymptomatically. This Review discusses the status and prospects of therapeutic strategies for countering neurodegenerative disorders of ageing by improving, preserving or rescuing brain energetics. The approaches described include restoring oxidative phosphorylation and glycolysis, increasing insulin sensitivity, correcting mitochondrial dysfunction, ketone-based interventions, acting via hormones that modulate cerebral energetics, RNA therapeutics and complementary multimodal lifestyle changes.
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Affiliation(s)
- Stephen C Cunnane
- Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada.
- Research Center on Aging, Sherbrooke, QC, Canada.
| | | | - Cecilie Morland
- Department of Pharmaceutical Biosciences, Institute of Pharmacy, University of Oslo, Oslo, Norway
| | - Alessandro Prigione
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, University of Dusseldorf, Dusseldorf, Germany
| | - Gemma Casadesus
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Zane B Andrews
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
- Department of Physiology, Monash University, Clayton, VIC, Australia
| | - M Flint Beal
- Department of Neurology, Weill Cornell Medicine, New York, NY, USA
| | - Linda H Bergersen
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | | | | | | | - Jenni Harvey
- Ninewells Hospital, University of Dundee, Dundee, UK
- Medical School, University of Dundee, Dundee, UK
| | - Ross Jeggo
- Centre for Therapeutic Innovation in Neuropsychiatry, Institut de Recherche Servier, Croissy sur Seine, France
| | - Jack H Jhamandas
- Department of Medicine, University of Albeta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Albeta, Edmonton, AB, Canada
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Clothide Mannoury la Cour
- Centre for Therapeutic Innovation in Neuropsychiatry, Institut de Recherche Servier, Croissy sur Seine, France
| | - William F Martin
- Institute of Molecular Evolution, University of Dusseldorf, Dusseldorf, Germany
| | | | - Paula I Moreira
- CNC Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Klaus-Armin Nave
- Department of Biosciences, University of Heidelberg, Heidelberg, Germany
| | - Tal Nuriel
- Columbia University Medical Center, New York, NY, USA
| | - Stéphane H R Oliet
- Neurocentre Magendie, INSERM U1215, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Frédéric Saudou
- University of Grenoble Alpes, Grenoble, France
- INSERM U1216, CHU Grenoble Alpes, Grenoble Institute Neurosciences, Grenoble, France
| | - Mark P Mattson
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Mark J Millan
- Centre for Therapeutic Innovation in Neuropsychiatry, Institut de Recherche Servier, Croissy sur Seine, France.
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20
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Aging Alters Olfactory Bulb Network Oscillations and Connectivity: Relevance for Aging-Related Neurodegeneration Studies. Neural Plast 2020; 2020:1703969. [PMID: 32774353 PMCID: PMC7396091 DOI: 10.1155/2020/1703969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/27/2020] [Accepted: 02/12/2020] [Indexed: 11/18/2022] Open
Abstract
The aging process eventually cause a breakdown in critical synaptic plasticity and connectivity leading to deficits in memory function. The olfactory bulb (OB) and the hippocampus, both regions of the brain considered critical for the processing of odors and spatial memory, are commonly affected by aging. Using an aged wild-type C57B/6 mouse model, we sought to define the effects of aging on hippocampal plasticity and the integrity of cortical circuits. Specifically, we measured the long-term potentiation of high-frequency stimulation (HFS-LTP) at the Shaffer-Collateral CA1 pyramidal synapses. Next, local field potential (LFP) spectra, phase-amplitude theta-gamma coupling (PAC), and connectivity through coherence were assessed in the olfactory bulb, frontal and entorhinal cortices, CA1, and amygdala circuits. The OB of aged mice showed a significant increase in the number of histone H2AX-positive neurons, a marker of DNA damage. While the input-output relationship measure of basal synaptic activity was found not to differ between young and aged mice, a pronounced decline in the slope of field excitatory postsynaptic potential (fEPSP) and the population spike amplitude (PSA) were found in aged mice. Furthermore, aging was accompanied by deficits in gamma network oscillations, a shift to slow oscillations, reduced coherence and theta-gamma PAC in the OB circuit. Thus, while the basal synaptic activity was unaltered in older mice, impairment in hippocampal synaptic transmission was observed only in response to HFS. However, age-dependent alterations in neural network appeared spontaneously in the OB circuit, suggesting the neurophysiological basis of synaptic deficits underlying olfactory processing. Taken together, the results highlight the sensitivity and therefore potential use of LFP quantitative network oscillations and connectivity at the OB level as objective electrophysiological markers that will help reveal specific dysfunctional circuits in aging-related neurodegeneration studies.
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21
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Hahn A, Pensold D, Bayer C, Tittelmeier J, González-Bermúdez L, Marx-Blümel L, Linde J, Groß J, Salinas-Riester G, Lingner T, von Maltzahn J, Spehr M, Pieler T, Urbach A, Zimmer-Bensch G. DNA Methyltransferase 1 (DNMT1) Function Is Implicated in the Age-Related Loss of Cortical Interneurons. Front Cell Dev Biol 2020; 8:639. [PMID: 32793592 PMCID: PMC7387673 DOI: 10.3389/fcell.2020.00639] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/25/2020] [Indexed: 01/19/2023] Open
Abstract
Increased life expectancy in modern society comes at the cost of age-associated disabilities and diseases. Aged brains not only show reduced excitability and plasticity, but also a decline in inhibition. Age-associated defects in inhibitory circuits likely contribute to cognitive decline and age-related disorders. Molecular mechanisms that exert epigenetic control of gene expression contribute to age-associated neuronal impairments. Both DNA methylation, mediated by DNA methyltransferases (DNMTs), and histone modifications maintain neuronal function throughout lifespan. Here we provide evidence that DNMT1 function is implicated in the age-related loss of cortical inhibitory interneurons. Dnmt1 deletion in parvalbumin-positive interneurons attenuates their age-related decline in the cerebral cortex. Moreover, conditional Dnmt1-deficient mice show improved somatomotor performance and reduced aging-associated transcriptional changes. A decline in the proteostasis network, responsible for the proper degradation and removal of defective proteins, is implicated in age- and disease-related neurodegeneration. Our data suggest that DNMT1 acts indirectly on interneuron survival in aged mice by modulating the proteostasis network during life-time.
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Affiliation(s)
- Anne Hahn
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Daniel Pensold
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany.,Department of Functional Epigenetics in the Animal Model, Institute of Biology II, RWTH Aachen University, Aachen, Germany
| | - Cathrin Bayer
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany.,Department of Functional Epigenetics in the Animal Model, Institute of Biology II, RWTH Aachen University, Aachen, Germany
| | - Jessica Tittelmeier
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Lourdes González-Bermúdez
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Lisa Marx-Blümel
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Jenice Linde
- Department of Functional Epigenetics in the Animal Model, Institute of Biology II, RWTH Aachen University, Aachen, Germany.,Research Training Group 2416 MultiSenses - MultiScales, RWTH Aachen University, Aachen, Germany
| | - Jonas Groß
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Gabriela Salinas-Riester
- Transcriptome and Genome Analysis Laboratory (TAL), Department of Developmental Biochemistry, University of Göttingen, Göttingen, Germany
| | - Thomas Lingner
- Transcriptome and Genome Analysis Laboratory (TAL), Department of Developmental Biochemistry, University of Göttingen, Göttingen, Germany
| | - Julia von Maltzahn
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Marc Spehr
- Research Training Group 2416 MultiSenses - MultiScales, RWTH Aachen University, Aachen, Germany.,Department of Chemosensation, Institute of Biology II, RWTH Aachen University, Aachen, Germany
| | - Tomas Pieler
- Centre for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Department of Developmental Biochemistry, University of Göttingen, Göttingen, Germany
| | - Anja Urbach
- Institute of Neurology, University Hospital Jena, Jena, Germany
| | - Geraldine Zimmer-Bensch
- Department of Functional Epigenetics, Institute of Human Genetics, University Hospital Jena, Jena, Germany.,Department of Functional Epigenetics in the Animal Model, Institute of Biology II, RWTH Aachen University, Aachen, Germany.,Research Training Group 2416 MultiSenses - MultiScales, RWTH Aachen University, Aachen, Germany
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22
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Richard N, Nikolic M, Mortensen EL, Osler M, Lauritzen M, Benedek K. Steady-state visual evoked potential temporal dynamics reveal correlates of cognitive decline. Clin Neurophysiol 2020; 131:836-846. [PMID: 32066102 DOI: 10.1016/j.clinph.2020.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 11/14/2019] [Accepted: 01/07/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVE A central concern in aging is the preservation of cognitive skills. Tools to detect cognitive decline are sparse. The aim of this study was to ascertain whether cognitive decline is accompanied by alterations in the temporal dynamics of steady-state visual evoked potentials (SSVEPs). METHODS We included 162 men from the Danish Metropolit birth cohort. Their cognitive trajectory was based on their intelligence test score at youth (age ~18), middle age (age ~56), and late middle age (age ~62). Subjects underwent cognitive tests and steady-state visual stimulation. Temporal dynamics of SSVEPs were assessed in terms of amplitude and phase coherence. RESULTS The latency and magnitude of the amplitude modulation of the 36-Hz response correlated negatively with subjects' cognition indices. Furthermore, negative cognition index was associated with loss of SSVEPs at 36 Hz, and both 8 Hz and 36 Hz in severe cases. CONCLUSION Latency and magnitude of gamma frequency SSVEPs increase with cognitive decline. This suggests that the facilitation of SSVEPs first becomes problematic at gamma frequencies, then at alpha frequencies. SIGNIFICANCE Our data suggests that the temporal dynamics of SSVEPs can be used as an indicator of cognitive impairment. Furthermore, evoked gamma oscillations are especially vulnerable in cognitive decline.
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Affiliation(s)
- Nelly Richard
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Miki Nikolic
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Erik Lykke Mortensen
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen, Denmark
| | - Merete Osler
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen, Denmark; Research Center for Prevention and Health, Rigshospitalet Glostrup, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Martin Lauritzen
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Nordre Ringvej 57, 2600 Glostrup, Denmark; Center for Healthy Aging and Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
| | - Krisztina Benedek
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Nordre Ringvej 57, 2600 Glostrup, Denmark
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23
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Murmu RP, Fordsmann JC, Cai C, Brazhe A, Thomsen KJ, Lauritzen M. Sensory Stimulation-Induced Astrocytic Calcium Signaling in Electrically Silent Ischemic Penumbra. Front Aging Neurosci 2019; 11:223. [PMID: 31496947 PMCID: PMC6712371 DOI: 10.3389/fnagi.2019.00223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/07/2019] [Indexed: 11/14/2022] Open
Abstract
Middle cerebral artery occlusion (MCAO) induces ischemia characterized by a densely ischemic focus, and a less densely ischemic penumbral zone in which neurons and astrocytes display age-dependent dynamic variations in spontaneous Ca2+ activities. However, it is unknown whether penumbral nerve cells respond to sensory stimulation early after stroke onset, which is critical for understanding stimulation-induced stroke therapy. In this study, we investigated the ischemic penumbra’s capacity to respond to somatosensory input. We examined adult (3- to 4-month-old) and old (18- to 24-month-old) male mice at 2–4 h after MCAO, using two-photon microscopy to record somatosensory stimulation-induced neuronal and astrocytic Ca2+ signals in the ischemic penumbra. In both adult and old mice, MCAO abolished spontaneous and stimulation-induced electrical activity in the penumbra, and strongly reduced stimulation-induced Ca2+ responses in neuronal somas (35–82%) and neuropil (92–100%) in the penumbra. In comparison, after stroke, stimulation-induced astrocytic Ca2+ responses in the penumbra were only moderately reduced (by 54–62%) in adult mice, and were even better preserved (reduced by 31–38%) in old mice. Our results suggest that somatosensory stimulation evokes astrocytic Ca2+ activity in the ischemic penumbra. We hypothesize that the relatively preserved excitability of astrocytes, most prominent in aged mice, may modulate protection from ischemic infarcts during early somatosensory activation of an ischemic cortical area. Future neuroprotective efforts in stroke may target spontaneous or stimulation-induced activity of astrocytes in the ischemic penumbra.
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Affiliation(s)
- Reena P Murmu
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Jonas C Fordsmann
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Changsi Cai
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow, Russia
| | - Kirsten J Thomsen
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| | - Martin Lauritzen
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
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24
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Horwitz A, Klemp M, Horwitz H, Thomsen MD, Rostrup E, Mortensen EL, Osler M, Lauritzen M, Benedek K. Brain Responses to Passive Sensory Stimulation Correlate With Intelligence. Front Aging Neurosci 2019; 11:201. [PMID: 31474849 PMCID: PMC6702683 DOI: 10.3389/fnagi.2019.00201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 07/17/2019] [Indexed: 11/13/2022] Open
Abstract
This study investigates the association between intelligence and brain power responses to a passive audiovisual stimulation. We measure the power of gamma-range steady-state responses (SSRs) as well as intelligence and other aspects of neurocognitive function in 40 healthy males born in 1953. The participants are a part of a Danish birth cohort study and the data therefore include additional information measured earlier in life. Our main power measure is the difference in power between a visual stimulation and a combined audiovisual stimulation. We hypothesize and establish empirically that the power measure is associated with intelligence. In particular, we find a highly significant correlation between the power measure and present intelligence scores. The association is robust to controlling for size-at-birth measures, length of education, speed of processing as well as a range of other potentially confounding factors. Interestingly, we find that intelligence scores measured earlier in life (childhood, youth, late midlife), are also correlated with the present-day power measure, suggesting a deep connection between intelligence and the power measure. Finally, we find that the power measure has a high sensitivity for detection of an intelligence score below the average.
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Affiliation(s)
- Anna Horwitz
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Marc Klemp
- Department of Economics, University of Copenhagen, Copenhagen, Denmark
- Department of Economics, Population Studies and Training Center, Brown University, Providence, RI, United States
| | - Henrik Horwitz
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Mia Dyhr Thomsen
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Egill Rostrup
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Erik Lykke Mortensen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Merete Osler
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
- Research Center for Prevention and Health, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Krisztina Benedek
- Department of Clinical Neurophysiology, Rigshospitalet Glostrup, Glostrup, Denmark
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25
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Schneider J, Berndt N, Papageorgiou IE, Maurer J, Bulik S, Both M, Draguhn A, Holzhütter HG, Kann O. Local oxygen homeostasis during various neuronal network activity states in the mouse hippocampus. J Cereb Blood Flow Metab 2019; 39:859-873. [PMID: 29099662 PMCID: PMC6501513 DOI: 10.1177/0271678x17740091] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/02/2017] [Indexed: 12/14/2022]
Abstract
Cortical information processing comprises various activity states emerging from timed synaptic excitation and inhibition. However, the underlying energy metabolism is widely unknown. We determined the cerebral metabolic rate of oxygen (CMRO2) along a tissue depth of <0.3 mm in the hippocampal CA3 region during various network activities, including gamma oscillations and sharp wave-ripples that occur during wakefulness and sleep. These physiological states associate with sensory perception and memory formation, and critically depend on perisomatic GABA inhibition. Moreover, we modelled vascular oxygen delivery based on quantitative microvasculature analysis. (1) Local CMRO2 was highest during gamma oscillations (3.4 mM/min), medium during sharp wave-ripples, asynchronous activity and isoflurane application (2.0-1.6 mM/min), and lowest during tetrodotoxin application (1.4 mM/min). (2) Energy expenditure of axonal and synaptic signaling accounted for >50% during gamma oscillations. (3) CMRO2 positively correlated with number and synchronisation of activated synapses, and neural multi-unit activity. (4) The median capillary distance was 44 µm. (5) The vascular oxygen partial pressure of 33 mmHg was needed to sustain oxidative phosphorylation during gamma oscillations. We conclude that gamma oscillations featuring high energetics require a hemodynamic response to match oxygen consumption of respiring mitochondria, and that perisomatic inhibition significantly contributes to the brain energy budget.
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Affiliation(s)
- Justus Schneider
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Nikolaus Berndt
- Computational Systems Biochemistry, Institute of Biochemistry, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Jana Maurer
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Sascha Bulik
- Computational Systems Biochemistry, Institute of Biochemistry, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Hermann-Georg Holzhütter
- Computational Systems Biochemistry, Institute of Biochemistry, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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26
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Fordsmann JC, Murmu RP, Cai C, Brazhe A, Thomsen KJ, Zambach SA, Lønstrup M, Lind BL, Lauritzen M. Spontaneous astrocytic Ca 2+ activity abounds in electrically suppressed ischemic penumbra of aged mice. Glia 2018; 67:37-52. [PMID: 30427548 DOI: 10.1002/glia.23506] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/12/2018] [Accepted: 07/03/2018] [Indexed: 12/11/2022]
Abstract
Experimental focal cortical ischemic lesions consist of an ischemic core and a potentially salvageable peri-ischemic region, the ischemic penumbra. The activity of neurons and astrocytes is assumed to be suppressed in the penumbra because the electrical function is interrupted, but this is incompletely elucidated. Most experimental stroke studies used young adult animals, whereas stroke is prevalent in the elderly population. Using two-photon imaging in vivo, we here demonstrate extensive but electrically silent, spontaneous Ca2+ activity in neurons and astrocytes in the ischemic penumbra of 18- to 24-month-old mice 2-4 hr after middle cerebral artery occlusion. In comparison, stroke reduced spontaneous Ca2+ activity in neurons and astrocytes in adult mice (3-4 months of age). In aged mice, stroke increased astrocytic spontaneous Ca2+ activity considerably while neuronal spontaneous Ca2+ activity was unchanged. Blockade of action potentials and of purinergic receptors strongly reduced spontaneous Ca2+ activity in both neurons and astrocytes in the penumbra of old stroke mice. This indicates that stroke had a direct influence on mechanisms in presynaptic terminals and on purinergic signaling. Thus, highly dynamic variations in spontaneous Ca2+ activity characterize the electrically compromised penumbra, with remarkable differences between adult and old mice. The data are consistent with the notion that aged neurons and astrocytes take on a different phenotype than young mice. The increased activity of the aged astrocyte phenotype may be harmful to neurons. We suggest that the abundant spontaneous Ca2+ activity in astrocytes in the ischemic penumbra of old mice may be a novel target for neuroprotection strategies. A video abstract of this article can be found at https://youtu.be/AKlwKFsz1qE.
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Affiliation(s)
- Jonas Christoffer Fordsmann
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Reena Prity Murmu
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Changsi Cai
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow, Russia
| | - Kirsten Joan Thomsen
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
| | - Stefan Andreas Zambach
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Micael Lønstrup
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Lykke Lind
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
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27
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Mohan A, Thalamuthu A, Mather KA, Zhang Y, Catts VS, Weickert CS, Sachdev PS. Differential expression of synaptic and interneuron genes in the aging human prefrontal cortex. Neurobiol Aging 2018; 70:194-202. [PMID: 30031232 DOI: 10.1016/j.neurobiolaging.2018.06.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 05/10/2018] [Accepted: 06/07/2018] [Indexed: 02/06/2023]
Abstract
Altered inhibition-excitation balance is implicated in brain aging. We hypothesized that expression of 14 genes encoding proteins localized to synapses or interneurons would show age-related changes relative to 1 another in postmortem tissue from the prefrontal cortex of 37 individuals (18-78 years) and that synaptic or interneuron markers would be differentially correlated with human brain volumes across aging. The majority of genes examined were differentially expressed with age, most being downregulated. Expression of 3 interneuron-related genes was significantly negatively associated with age (calbindin, somatostatin, cholecystokinin), whereas 3 synapse-related genes showed significant age-related expression change (PSD95, GAP43, VGLUT1). On covarying for 2 glial markers (GFAP, IBA1), all 3 interneuron genes and 1 synaptic gene (Growth-associated protein 43) remained significant. Two genes were significantly associated with total brain volume (calbindin, complexin 2) and a marker of synaptic density (synaptophysin) was significantly associated with cortical gray matter volume. Age-related change in expression of genes involved in maintenance of inhibition-excitation balance and regulation of prefrontocortical network dynamics suggests these pathways may contribute to brain aging.
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Affiliation(s)
- Adith Mohan
- Centre for Healthy Brain Ageing (CHeBA), University of New South Wales (UNSW) Australia, Sydney, New South Wales, Australia; School of Psychiatry, UNSW Australia, Sydney, New South Wales, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Randwick, New South Wales, Australia.
| | - Anbupalam Thalamuthu
- Centre for Healthy Brain Ageing (CHeBA), University of New South Wales (UNSW) Australia, Sydney, New South Wales, Australia
| | - Karen A Mather
- Centre for Healthy Brain Ageing (CHeBA), University of New South Wales (UNSW) Australia, Sydney, New South Wales, Australia
| | - Yiru Zhang
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Vibeke S Catts
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Cynthia Shannon Weickert
- School of Psychiatry, UNSW Australia, Sydney, New South Wales, Australia; Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Perminder S Sachdev
- Centre for Healthy Brain Ageing (CHeBA), University of New South Wales (UNSW) Australia, Sydney, New South Wales, Australia; School of Psychiatry, UNSW Australia, Sydney, New South Wales, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Randwick, New South Wales, Australia
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28
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Horwitz A, Mortensen EL, Osler M, Fagerlund B, Lauritzen M, Benedek K. Passive Double-Sensory Evoked Coherence Correlates with Long-Term Memory Capacity. Front Hum Neurosci 2017; 11:598. [PMID: 29311868 PMCID: PMC5735981 DOI: 10.3389/fnhum.2017.00598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/24/2017] [Indexed: 01/22/2023] Open
Abstract
HIGHLIGHTS Memory correlates with the difference between single and double-sensory evoked steady-state coherence in the gamma range (ΔC).The correlation is most pronounced for the anterior brain region (ΔCA ).The correlation is not driven by birth size, education, speed of processing, or intelligence.The sensitivity of ΔCA for detecting low memory capacity is 90%. Cerebral rhythmic activity and oscillations are important pathways of communication between cortical cell assemblies and may be key factors in memory. We asked whether memory performance is related to gamma coherence in a non-task sensory steady-state stimulation. We investigated 40 healthy males born in 1953 who were part of a Danish birth cohort study. Coherence was measured in the gamma range in response to a single-sensory visual stimulation (36 Hz) and a double-sensory combined audiovisual stimulation (auditive: 40 Hz; visual: 36 Hz). The individual difference in coherence (ΔC) between the bimodal and monomodal stimulation was calculated for each subject and used as the main explanatory variable. ΔC in total brain were significantly negatively correlated with long-term verbal recall. This correlation was pronounced for the anterior region. In addition, the correlation between ΔC and long-term memory was robust when controlling for working memory, as well as a wide range of potentially confounding factors, including intelligence, length of education, speed of processing, visual attention and executive function. Moreover, we found that the difference in anterior coherence (ΔCA ) is a better predictor of memory than power in multivariate models. The sensitivity of ΔCA for detecting low memory capacity is 92%. Finally, ΔCA was also associated with other types of memory: verbal learning, visual recognition, and spatial memory, and these additional correlations were also robust enough to control for a range of potentially confounding factors. Thus, the ΔC is a predictor of memory performance may be useful in cognitive neuropsychological testing.
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Affiliation(s)
- Anna Horwitz
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet - Glostrup, Glostrup, Denmark
| | - Erik L Mortensen
- Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Merete Osler
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark.,Research Center for Prevention and Health, Rigshospitalet - Glostrup, Glostrup, Denmark
| | - Birgitte Fagerlund
- Center for Neuropsychiatric Schizophrenia Research, Psychiatric Center Glostrup, Glostrup, Denmark.,Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, Psychiatric Center Glostrup, Glostrup, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet - Glostrup, Glostrup, Denmark
| | - Krisztina Benedek
- Department of Clinical Neurophysiology, Rigshospitalet - Glostrup, Glostrup, Denmark
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29
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Age-dependent and region-specific alteration of parvalbumin neurons and perineuronal nets in the mouse cerebral cortex. Neurochem Int 2017; 112:59-70. [PMID: 29126935 DOI: 10.1016/j.neuint.2017.11.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/28/2017] [Accepted: 11/01/2017] [Indexed: 12/21/2022]
Abstract
Cognitive function declines with age. Such function depends on γ-oscillation in the frontal cortex. Pyramidal neurons, and the parvalbumin-expressing interneurons (PV neurons) that control them, are important for the generation of γ-oscillation. The mechanism by which cognitive function declines is unclear. Perineuronal nets (PNNs) mainly surround the soma and proximal dendrites and axon segments of PV neurons in the cerebral cortex. Previous evidence indicates that PNNs inhibit neural plasticity. If this is true, an increase in the number of neurons surrounded by PNNs or in the thickness or density of the PNNs around neurons could decrease plasticity in the cortex. To determine if an aging-related change in cortical PNNs occurs, we examined the influence of aging on PV neurons and whether Wisteria floribunda agglutinin-positive PNNs differ depending on the cortical area. The results showed that the number of PV neurons/mm2 did not change in many areas of the cortex as mice aged. In contrast, the number of neurons in the sensory cortex surrounded by PNNs increased as mice aged. Thus, with age, PNN density increases in some cortical areas but not in others. In addition, the expression level of PV protein in PV neurons decreased with aging in the whole cortex. We suggest that decreased expression of PV protein impairs fast spiking in PV neurons. We propose that PNNs surround more neurons as age increases. This aging-related increase in PNNs decreases plasticity in the cerebral cortex and reduces cognitive function. The first step in investigating this proposal would be to determine if PNN density increases with age.
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30
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Disturbances in the control of capillary flow in an aged APP swe/PS1ΔE9 model of Alzheimer's disease. Neurobiol Aging 2017; 62:82-94. [PMID: 29131981 DOI: 10.1016/j.neurobiolaging.2017.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 10/04/2017] [Accepted: 10/06/2017] [Indexed: 02/08/2023]
Abstract
Vascular changes are thought to contribute to the development of Alzheimer's disease, and both cerebral blood flow and its responses during neural activation are reduced before Alzheimer's disease symptoms onset. One hypothetical explanation is that capillary dysfunction reduces oxygen extraction efficacy. This study compares the morphology and hemodynamics of the microvasculature in the somatosensory cortex of 18-month-old APPSWE/PS1ΔE9 (transgenic [Tg]) mice and wild-type (WT) littermates. In particular, the extent to which their capillary transit times homogenize during functional activation was measured and compared. Capillary length density was similar in both groups but capillary blood flow during rest was lower in the Tg mice, indicating that cortical oxygen availability is reduced. The capillary hemodynamic response to functional activation was larger, and lasted longer in Tg mice than in WT mice. The homogenization of capillary transit times during functional activation, which we previously demonstrated in young mice, was absent in the Tg mice. This study demonstrates that both neurovascular coupling and capillary function are profoundly disturbed in aged Tg and WT mice.
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31
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Horwitz A, Dyhr Thomsen M, Wiegand I, Horwitz H, Klemp M, Nikolic M, Rask L, Lauritzen M, Benedek K. Visual steady state in relation to age and cognitive function. PLoS One 2017; 12:e0171859. [PMID: 28245274 PMCID: PMC5330460 DOI: 10.1371/journal.pone.0171859] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/26/2017] [Indexed: 12/25/2022] Open
Abstract
Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit) with varying cognitive ability. In particular, we examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power (ΔRV) with cognitive scores for the older adults. We find that ΔRV decrease with age by just over one standard deviation when comparing young with old participants (p<0.01). Furthermore, intelligence is significantly negatively correlated with ΔRV in the older adult cohort, even when processing speed, global cognition, executive function, memory, and education (p<0.05). In our preferred specification, an increase in ΔRV of one standard deviation is associated with a reduction in intelligence of 48% of a standard deviation (p<0.01). Finally, we conclude that the difference in cerebral rhythmic activity between the alpha and gamma bands is associated with age and cognitive status, and that ΔRV therefore provide a non-subjective clinical tool with which to examine cognitive status in old age.
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Affiliation(s)
- Anna Horwitz
- Department of Neuroscience and Pharmacology, University of Copenhagen, Blegdamsvej 3, Copenhagen, Denmark
- Center for Healthy Aging, University of Copenhagen, Blegdamsvej 3, Copenhagen, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
- * E-mail:
| | - Mia Dyhr Thomsen
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
| | - Iris Wiegand
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, Copenhagen, Denmark
| | - Henrik Horwitz
- Department of Clinical Pharmacology, Bispebjerg Hospital, Bispebjerg Bakke 23, København NV, Denmark
| | - Marc Klemp
- Department of Economics and Population Studies & Training Center, Brown University, Providence, Rhode Island, United States of America
- Department of Economics, University of Copenhagen, Øster Farimagsgade 5, Copenhagen, Denmark
| | - Miki Nikolic
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
| | - Lene Rask
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Blegdamsvej 3, Copenhagen, Denmark
- Center for Healthy Aging, University of Copenhagen, Blegdamsvej 3, Copenhagen, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
| | - Krisztina Benedek
- Department of Clinical Neurophysiology, Rigshospitalet–Glostrup, Nordre Ringvej 57, Glostrup, Denmark
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Lecrux C, Sandoe CH, Neupane S, Kropf P, Toussay X, Tong XK, Lacalle-Aurioles M, Shmuel A, Hamel E. Impact of Altered Cholinergic Tones on the Neurovascular Coupling Response to Whisker Stimulation. J Neurosci 2017; 37:1518-1531. [PMID: 28069927 PMCID: PMC6705676 DOI: 10.1523/jneurosci.1784-16.2016] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 12/22/2016] [Accepted: 12/30/2016] [Indexed: 11/21/2022] Open
Abstract
Brain imaging techniques that use vascular signals to map changes in neuronal activity rely on the coupling between electrophysiology and hemodynamics, a phenomenon referred to as "neurovascular coupling" (NVC). It is unknown whether this relationship remains reliable under altered brain states associated with acetylcholine (ACh) levels, such as attention and arousal and in pathological conditions such as Alzheimer's disease. We therefore assessed the effects of varying ACh tone on whisker-evoked NVC responses in rat barrel cortex, measured by cerebral blood flow (CBF) and neurophysiological recordings (local field potentials, LFPs). We found that acutely enhanced ACh tone significantly potentiated whisker-evoked CBF responses through muscarinic ACh receptors and concurrently facilitated neuronal responses, as illustrated by increases in the amplitude and power in high frequencies of the evoked LFPs. However, the cellular identity of the activated neuronal network within the responsive barrel was unchanged, as characterized by c-Fos upregulation in pyramidal cells and GABA interneurons coexpressing vasoactive intestinal polypeptide. In contrast, chronic ACh deprivation hindered whisker-evoked CBF responses and the amplitude and power in most frequency bands of the evoked LFPs and reduced the rostrocaudal extent and area of the activated barrel without altering its identity. Correlations between LFP power and CBF, used to estimate NVC, were enhanced under high ACh tone and disturbed significantly by ACh depletion. We conclude that ACh is not only a facilitator but also a prerequisite for the full expression of sensory-evoked NVC responses, indicating that ACh may alter the fidelity of hemodynamic signals in assessing changes in evoked neuronal activity.SIGNIFICANCE STATEMENT Neurovascular coupling, defined as the tight relationship between activated neurons and hemodynamic responses, is a fundamental brain function that underlies hemodynamic-based functional brain imaging techniques. However, the impact of altered brain states on this relationship is largely unknown. We therefore investigated how acetylcholine (ACh), known to drive brain states of attention and arousal and to be deficient in pathologies such as Alzheimer's disease, would alter neurovascular coupling responses to sensory stimulation. Whereas acutely increased ACh enhanced neuronal responses and the resulting hemodynamic signals, chronic loss of cholinergic input resulted in dramatic impairments in both types of sensory-evoked signals. We conclude that ACh is not only a potent modulator but also a requirement for the full expression of sensory-evoked neurovascular coupling responses.
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Affiliation(s)
- Clotilde Lecrux
- Laboratory of Cerebrovascular Research and
- Laboratory of Brain Imaging Signals, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada H3A 2B4
| | | | - Sujaya Neupane
- Laboratory of Brain Imaging Signals, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada H3A 2B4
| | - Pascal Kropf
- Laboratory of Brain Imaging Signals, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada H3A 2B4
| | | | | | | | - Amir Shmuel
- Laboratory of Brain Imaging Signals, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada H3A 2B4
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33
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Toth P, Tarantini S, Csiszar A, Ungvari Z. Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging. Am J Physiol Heart Circ Physiol 2017; 312:H1-H20. [PMID: 27793855 PMCID: PMC5283909 DOI: 10.1152/ajpheart.00581.2016] [Citation(s) in RCA: 324] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/10/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer's disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined.
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Affiliation(s)
- Peter Toth
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Pecs, Hungary; and
| | - Stefano Tarantini
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anna Csiszar
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
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34
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Tarantini S, Tran CHT, Gordon GR, Ungvari Z, Csiszar A. Impaired neurovascular coupling in aging and Alzheimer's disease: Contribution of astrocyte dysfunction and endothelial impairment to cognitive decline. Exp Gerontol 2016; 94:52-58. [PMID: 27845201 DOI: 10.1016/j.exger.2016.11.004] [Citation(s) in RCA: 274] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/02/2016] [Accepted: 11/10/2016] [Indexed: 12/11/2022]
Abstract
The importance of (micro)vascular contributions to cognitive impairment and dementia (VCID) in aging cannot be overemphasized, and the pathogenesis and prevention of age-related cerebromicrovascular pathologies are a subject of intensive research. In particular, aging impairs the increase in cerebral blood flow triggered by neural activation (termed neurovascular coupling or functional hyperemia), a critical mechanism that matches oxygen and nutrient delivery with the increased demands in active brain regions. From epidemiological, clinical and experimental studies the picture emerges of a complex functional impairment of cerebral microvessels and astrocytes, which likely contribute to neurovascular dysfunction and cognitive decline in aging and in age-related neurodegenerative diseases. This overview discusses age-related alterations in neurovascular coupling responses responsible for impaired functional hyperemia. The mechanisms and consequences of astrocyte dysfunction (including potential alteration of astrocytic endfeet calcium signaling, dysregulation of eicosanoid gliotransmitters and astrocyte energetics) and functional impairment of the microvascular endothelium are explored. Age-related mechanisms (cellular oxidative stress, senescence, circulating IGF-1 deficiency) impairing the function of cells of the neurovascular unit are discussed and the evidence for the causal role of neurovascular uncoupling in cognitive decline is critically examined.
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Affiliation(s)
- Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Cam Ha T Tran
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Anna Csiszar
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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