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Pereira PA, Tavares M, Laires M, Mota B, Madeira MD, Paula-Barbosa MM, Cardoso A. Effects of Aging and Nerve Growth Factor on Neuropeptide Expression and Cholinergic Innervation of the Rat Basolateral Amygdala. BIOLOGY 2024; 13:155. [PMID: 38534426 DOI: 10.3390/biology13030155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/28/2024]
Abstract
The basolateral amygdala (BLA) contains interneurons that express neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), both of which are involved in the regulation of functions and behaviors that undergo deterioration with aging. There is considerable evidence that, in some brain areas, the expression of NPY and VIP might be modulated by acetylcholine. Importantly, the BLA is one of the brain regions that has one of the densest cholinergic innervations, which arise mainly from the basal forebrain cholinergic neurons. These cholinergic neurons depend on nerve growth factor (NGF) for their survival, connectivity, and function. Thus, in this study, we sought to determine if aging alters the densities of NPY- and VIP-positive neurons and cholinergic varicosities in the BLA and, in the affirmative, if those changes might rely on insufficient trophic support provided by NGF. The number of NPY-positive neurons was significantly reduced in aged rats, whereas the number of VIP-immunoreactive neurons was unaltered. The decreased NPY expression was fully reversed by the infusion of NGF in the lateral ventricle. The density of cholinergic varicosities was similar in adult and old rats. On the other hand, the density of cholinergic varicosities is significantly higher in old rats treated with NGF than in adult and old rats. Our results indicate a dissimilar resistance of different populations of BLA interneurons to aging. Furthermore, the present data also show that the BLA cholinergic innervation is particularly resistant to aging effects. Finally, our results also show that the reduced NPY expression in the BLA of aged rats can be related to changes in the NGF neurotrophic support.
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Affiliation(s)
- Pedro A Pereira
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- NeuroGen Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Dr. Plácido da Costa, 4200-450 Porto, Portugal
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Marta Tavares
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Miguel Laires
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Bárbara Mota
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Maria Dulce Madeira
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- NeuroGen Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Dr. Plácido da Costa, 4200-450 Porto, Portugal
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Manuel M Paula-Barbosa
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Armando Cardoso
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- NeuroGen Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Dr. Plácido da Costa, 4200-450 Porto, Portugal
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
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2
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Allard S, Hussain Shuler MG. Cholinergic Reinforcement Signaling Is Impaired by Amyloidosis Prior to Its Synaptic Loss. J Neurosci 2023; 43:6988-7005. [PMID: 37648452 PMCID: PMC10586537 DOI: 10.1523/jneurosci.0967-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/03/2023] [Accepted: 08/26/2023] [Indexed: 09/01/2023] Open
Abstract
Alzheimer's disease (AD) is associated with amyloidosis and dysfunction of the cholinergic system, which is crucial for learning and memory. However, the nature of acetylcholine signaling within regions of cholinergic-dependent plasticity and how it changes with experience is poorly understood, much less the impact of amyloidosis on this signaling. Therefore, we optically measure the release profile of acetylcholine to unexpected, predicted, and predictive events in visual cortex (VC)-a site of known cholinergic-dependent plasticity-in a preclinical mouse model of AD that develops amyloidosis. We find that acetylcholine exhibits reinforcement signaling qualities, reporting behaviorally relevant outcomes and displaying release profiles to predictive and predicted events that change as a consequence of experience. We identify three stages of amyloidosis occurring before the degeneration of cholinergic synapses within VC and observe that cholinergic responses in amyloid-bearing mice become impaired over these stages, diverging progressively from age- and sex-matched littermate controls. In particular, amyloidosis degrades the signaling of unexpected rewards and punishments, and attenuates the experience-dependent (1) increase of cholinergic responses to outcome predictive visual cues, and (2) decrease of cholinergic responses to predicted outcomes. Hyperactive spontaneous acetylcholine release occurring transiently at the onset of impaired cholinergic signaling is also observed, further implicating disrupted cholinergic activity as an early functional biomarker in AD. Our findings suggest that acetylcholine acts as a reinforcement signal that is impaired by amyloidosis before pathologic degeneration of the cholinergic system, providing a deeper understanding of the effects of amyloidosis on acetylcholine signaling and informing future interventions for AD.SIGNIFICANCE STATEMENT The cholinergic system is especially vulnerable to the neurotoxic effects of amyloidosis, a hallmark of Alzheimer's disease (AD). Though amyloid-induced cholinergic synaptic loss is thought in part to account for learning and memory impairments in AD, little is known regarding how amyloid impacts signaling of the cholinergic system before its anatomic degeneration. Optical measurement of acetylcholine (ACh) release in a mouse model of AD that develops amyloidosis reveals that ACh signals reinforcement and outcome prediction that is disrupted by amyloidosis before cholinergic degeneration. These observations have important scientific and clinical implications: they implicate ACh signaling as an early functional biomarker, provide a deeper understanding of the action of acetylcholine, and inform on when and how intervention may best ameliorate cognitive decline in AD.
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Affiliation(s)
- Simon Allard
- Kavli Neuroscience Discovery Institute, Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Marshall G Hussain Shuler
- Kavli Neuroscience Discovery Institute, Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Zhang XQ, Xu L, Yang SY, Hu LB, Dong FY, Sun BG, Shen HW. Reduced Synaptic Transmission and Intrinsic Excitability of a Subtype of Pyramidal Neurons in the Medial Prefrontal Cortex in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 84:129-140. [PMID: 34487044 DOI: 10.3233/jad-210585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Abnormal morphology and function of neurons in the prefrontal cortex (PFC) are associated with cognitive deficits in rodent models of Alzheimer's disease (AD), particularly in cortical layer-5 pyramidal neurons that integrate inputs from different sources and project outputs to cortical or subcortical structures. Pyramidal neurons in layer-5 of the PFC can be classified as two subtypes depending on the inducibility of prominent hyperpolarization-activated cation currents (h-current). However, the differences in the neurophysiological alterations between these two subtypes in rodent models of AD remain poorly understood. OBJECTIVE To investigate the neurophysiological alterations between two subtypes of pyramidal neurons in hAPP-J20 mice, a transgenic model for early onset AD. METHODS The synaptic transmission and intrinsic excitability of pyramidal neurons were investigated using whole-cell patch recordings. The morphological complexity of pyramidal neurons was detected by biocytin labelling and subsequent Sholl analysis. RESULTS We found reduced synaptic transmission and intrinsic excitability of the prominent h-current (PH) cells but not the non-PH cells in hAPP-J20 mice. Furthermore, the function of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels which mediated h-current was disrupted in the PH cells of hAPP-J20 mice. Sholl analysis revealed that PH cells had less dendritic intersections in hAPP-J20 mice comparing to control mice, implying that a lower morphological complexity might contribute to the reduced neuronal activity. CONCLUSION These results suggest that the PH cells in the medial PFC may be more vulnerable to degeneration in hAPP-J20 mice and play a sustainable role in frontal dysfunction in AD.
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Affiliation(s)
- Xiao-Qin Zhang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Le Xu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Si-Yu Yang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Lin-Bo Hu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Fei-Yuan Dong
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Bing-Gui Sun
- Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hao-Wei Shen
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
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4
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Effects of aging on the cholinergic innervation of the rat ventral tegmental area: A stereological study. Exp Gerontol 2021; 148:111298. [PMID: 33652122 DOI: 10.1016/j.exger.2021.111298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 02/12/2021] [Accepted: 02/22/2021] [Indexed: 11/21/2022]
Abstract
Dopamine neurons in the ventral tegmental area (VTA) play a main role in processing both rewarding and aversive stimuli, and their response to salient stimuli is significantly shaped by afferents originating in the brainstem cholinergic nuclei. Aging is associated with a decline in dopaminergic activity and reduced response to positive reinforcement. We have used stereological techniques to examine, in adult and aged rats, the dopaminergic neurons and the cholinergic innervation of the VTA, and the cholinergic populations of the pedunculopontine tegmental (PPT) and laterodorsal tegmental (LDT) nuclei, which are the only source of cholinergic inputs to the VTA. In the VTA, there were no age-related variations in the number and size of tyrosine hydroxylase (TH)-immunoreactive neurons, but the density of cholinergic varicosities was reduced in aged rats. The total number of choline acetyltransferase (ChAT)-immunoreactive neurons in the PPT and LDT was unchanged, but their somas were hypertrophied in aged rats. Our results suggest that dysfunction of the cholinergic system might contribute for the age-associated deterioration of the brain reward system.
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Rozycka A, Charzynska A, Misiewicz Z, Maciej Stepniewski T, Sobolewska A, Kossut M, Liguz-Lecznar M. Glutamate, GABA, and Presynaptic Markers Involved in Neurotransmission Are Differently Affected by Age in Distinct Mouse Brain Regions. ACS Chem Neurosci 2019; 10:4449-4461. [PMID: 31556991 DOI: 10.1021/acschemneuro.9b00220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Molecular synaptic aging perturbs neurotransmission and decreases the potential for neuroplasticity. The direction and degree of changes observed in aging are often region or cell specific, hampering the generalization of age-related effects. Using real-time PCR and Western blot analyses, we investigated age-related changes in several presynaptic markers (Vglut1, Vglut2, Gad65, Gad67, Vgat, synaptophysin) involved in the initial steps of glutamatergic and GABAergic neurotransmission, in several cortical regions, in young (3-4 months old), middle-aged (1 year old), and old (2 years old) mice. We found age-related changes mainly in protein levels while, apart from the occipital cortex, virtually no significant changes in mRNA levels were detected, which suggests that aging acts on the investigated markers mainly through post-transcriptional mechanisms depending on the brain region. Principal component analysis (PCA) of protein data revealed that each brain region possessed a type of "biochemical distinctiveness" (each analyzed brain region was best characterized by higher variability level of a particular synaptic marker) that was lost with age. Analysis of glutamate and γ-aminobutyric acid (GABA) levels in aging suggested that mechanisms keeping an overall balance between the two amino acids in the brain are weakened in the hippocampus. Our results unravel the differences in mRNA/protein interactions in the aging brain.
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Affiliation(s)
- Aleksandra Rozycka
- Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Agata Charzynska
- Laboratory of Bioinformatics, Neurobiology Center, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland
| | - Zuzanna Misiewicz
- Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
- Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki FI-00014, Finland
| | - Tomasz Maciej Stepniewski
- Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
- Research Programme on Biomedical Informatics (GRIB) - Department of Experimental and Health Sciences, Hospital del Mar Medical Research Institute, Pompeu Fabra University, 08002 Barcelona, Spain
| | - Alicja Sobolewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Str., 02-957 Warsaw, Poland
| | - Malgorzata Kossut
- Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
- Faculty of Psychology, SWPS University of Social Sciences and Humanities, 03-815 Warsaw, Poland
| | - Monika Liguz-Lecznar
- Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
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6
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Structural and molecular correlates of cognitive aging in the rat. Sci Rep 2019; 9:2005. [PMID: 30765864 PMCID: PMC6376121 DOI: 10.1038/s41598-019-39645-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 06/01/2018] [Indexed: 12/12/2022] Open
Abstract
Aging is associated with cognitive decline. Herein, we studied a large cohort of old age and young adult male rats and confirmed that, as a group, old rats display poorer spatial learning and behavioral flexibility than younger adults. Surprisingly, when animals were clustered as good and bad performers, our data revealed that while in younger animals better cognitive performance was associated with longer dendritic trees and increased levels of synaptic markers in the hippocampus and prefrontal cortex, the opposite was found in the older group, in which better performance was associated with shorter dendrites and lower levels of synaptic markers. Additionally, in old, but not young individuals, worse performance correlated with increased levels of BDNF and the autophagy substrate p62, but decreased levels of the autophagy complex protein LC3. In summary, while for younger individuals “bigger is better”, “smaller is better” is a more appropriate aphorism for older subjects.
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7
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Loss of precuneus dendritic spines immunopositive for spinophilin is related to cognitive impairment in early Alzheimer's disease. Neurobiol Aging 2017; 55:159-166. [PMID: 28259365 PMCID: PMC5440205 DOI: 10.1016/j.neurobiolaging.2017.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/27/2017] [Accepted: 01/27/2017] [Indexed: 01/25/2023]
Abstract
Precuneus (PreC) cortex is affected with amyloid plaques early in Alzheimer's disease (AD), and this pathology may be associated with alterations in PreC synapses and cognitive impairment. We quantified the spinophilin-immunoreactive (ir) dendritic spine density and the intensity of spinophilin immunofluorescence, the latter as a measure of relative protein levels of spinophilin, in PreC lamina III from 33 subjects with clinical diagnoses of no cognitive impairment (NCI), mild cognitive impairment (MCI), mild-moderate AD (mAD), or severe AD (sAD). Both measures of spinophilin were lower in mAD and sAD compared with NCI. The MCI group had higher protein levels of spinophilin compared with mAD and sAD, and higher spinophilin-ir dendritic spine density compared with sAD. Lower spinophilin-ir dendritic spine density and relative protein levels of spinophilin were associated with greater amyloid beta (Aβ) plaque burden, detected with a derivative of Pittsburgh compound-B (6-CN-PiB), and worse cognitive performance. Clinical onset of AD is marked by the loss of PreC spinophilin-ir dendritic spines that is related to Aβ pathology and may contribute to cognitive symptoms early in the disease.
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8
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Pereira PA, Millner T, Vilela M, Sousa S, Cardoso A, Madeira MD. Nerve growth factor-induced plasticity in medial prefrontal cortex interneurons of aged Wistar rats. Exp Gerontol 2016; 85:59-70. [DOI: 10.1016/j.exger.2016.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/04/2016] [Accepted: 09/20/2016] [Indexed: 01/03/2023]
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9
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Wang F, Bélanger E, Paquet ME, Côté DC, De Koninck Y. Probing pain pathways with light. Neuroscience 2016; 338:248-271. [PMID: 27702648 DOI: 10.1016/j.neuroscience.2016.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 02/06/2023]
Abstract
We have witnessed an accelerated growth of photonics technologies in recent years to enable not only monitoring the activity of specific neurons, while animals are performing certain types of behavior, but also testing whether specific cells, circuits, and regions are sufficient or necessary for initiating, maintaining, or altering this or that behavior. Compared to other sensory systems, however, such as the visual or olfactory system, photonics applications in pain research are only beginning to emerge. One reason pain studies have lagged behind is that many of the techniques originally developed cannot be directly implemented to study key relay sites within pain pathways, such as the skin, dorsal root ganglia, spinal cord, and brainstem. This is due, in part, to difficulties in accessing these structures with light. Here we review a number of recent advances in design and delivery of light-sensitive molecular probes (sensors and actuators) into pain relay circuits to help decipher their structural and functional organization. We then discuss several challenges that have hampered hardware access to specific structures including light scattering, tissue movement and geometries. We review a number of strategies to circumvent these challenges, by delivering light into, and collecting it from the different key sites to unravel how nociceptive signals are encoded at each level of the neuraxis. We conclude with an outlook on novel imaging modalities for label-free chemical detection and opportunities for multimodal interrogation in vivo. While many challenges remain, these advances offer unprecedented opportunities to bridge cellular approaches with context-relevant behavioral testing, an essential step toward improving translation of basic research findings into clinical applications.
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Affiliation(s)
- Feng Wang
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada
| | - Erik Bélanger
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada
| | - Marie-Eve Paquet
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Département de biochimie, microbiologie et bioinformatique, Université Laval, Québec, QC, Canada
| | - Daniel C Côté
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, QC, Canada
| | - Yves De Koninck
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de psychiatrie et neurosciences, Université Laval, Québec, QC, Canada.
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Knockdown of microRNA-195 contributes to protein phosphatase-2A inactivation in rats with chronic brain hypoperfusion. Neurobiol Aging 2016; 45:76-87. [DOI: 10.1016/j.neurobiolaging.2016.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/25/2016] [Accepted: 05/10/2016] [Indexed: 12/26/2022]
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Beta-hydroxy-beta-methylbutyrate ameliorates aging effects in the dendritic tree of pyramidal neurons in the medial prefrontal cortex of both male and female rats. Neurobiol Aging 2016; 40:78-85. [PMID: 26973106 DOI: 10.1016/j.neurobiolaging.2016.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 11/22/2022]
Abstract
Beta-hydroxy-beta-methylbutyrate (HMB), a supplement commonly used to maintain muscle in elderly and clinical populations, has been unexplored in the aging brain. In both healthy aging humans and rat models, there are cognitive deficits associated with age-related dendritic shrinkage within the prefrontal cortex. The present study explores the effects of relatively short- and long-term (7 and 31 weeks) oral HMB supplementation starting at 12 months of age in male and female rats on the dendritic tree of layer 5 pyramidal neurons in the medial prefrontal cortex. Since female rats continue to secrete ovarian hormones after reaching reproductive senescence, middle-aged female rats were ovariectomized to model humans. As expected, there were fewer spines and a retraction of dendritic material in the apical and basilar trees in old age controls of both sexes compared with their middle-aged counterparts. However, these losses did not occur in the HMB-treated rats in either dendrites or the total number of dendritic spines. Thus, HMB forestalled the effects of aging on the dendritic tree of this population of neurons.
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12
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Samanez-Larkin GR, Knutson B. Decision making in the ageing brain: changes in affective and motivational circuits. Nat Rev Neurosci 2015; 16:278-89. [PMID: 25873038 DOI: 10.1038/nrn3917] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
As the global population ages, older decision makers will be required to take greater responsibility for their own physical, psychological and financial well-being. With this in mind, researchers have begun to examine the effects of ageing on decision making and associated neural circuits. A new 'affect-integration-motivation' (AIM) framework may help to clarify how affective and motivational circuits support decision making. Recent research has shed light on whether and how ageing influences these circuits, providing an interdisciplinary account of how ageing can alter decision making.
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Affiliation(s)
- Gregory R Samanez-Larkin
- 1] Department of Psychology, 2 Hillhouse Avenue, Yale University, New Haven, Connecticut 06520, USA. [2]
| | - Brian Knutson
- 1] Department of Psychology, Building 420, Jordan Hall, Stanford University, Stanford, California 94305, USA. [2]
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Zhao W, Luo C, Wang J, Gong J, Li B, Gong Y, Wang J, Wang H. 3-N-butylphthalide improves neuronal morphology after chronic cerebral ischemia. Neural Regen Res 2014; 9:719-26. [PMID: 25206879 PMCID: PMC4146270 DOI: 10.4103/1673-5374.131576] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 11/06/2022] Open
Abstract
3-N-butylphthalide is an effective drug for acute ischemic stroke. However, its effects on chronic cerebral ischemia-induced neuronal injury remain poorly understood. Therefore, this study ligated bilateral carotid arteries in 15-month-old rats to simulate chronic cerebral ischemia in aged humans. Aged rats were then intragastrically administered 3-n-butylphthalide. 3-N-butylphthalide administration improved the neuronal morphology in the cerebral cortex and hippocampus of rats with chronic cerebral ischemia, increased choline acetyltransferase activity, and decreased malondialdehyde and amyloid beta levels, and greatly improved cognitive function. These findings suggest that 3-n-butylphthalide alleviates oxidative stress caused by chronic cerebral ischemia, improves cholinergic function, and inhibits amyloid beta accumulation, thereby improving cerebral neuronal injury and cognitive deficits.
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Affiliation(s)
- Wanhong Zhao
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Chao Luo
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Jue Wang
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Jian Gong
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Bin Li
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Yingxia Gong
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Jun Wang
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Hanqin Wang
- Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei Province, China
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14
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Duarte J, Schuck PF, Wenk GL, Ferreira GC. Metabolic disturbances in diseases with neurological involvement. Aging Dis 2014; 5:238-55. [PMID: 25110608 DOI: 10.14336/ad.2014.0500238] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 11/26/2013] [Accepted: 11/27/2013] [Indexed: 12/19/2022] Open
Abstract
Degeneration of specific neuronal populations and progressive nervous system dysfunction characterize neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. These findings are also reported in inherited diseases such as phenylketonuria and glutaric aciduria type I. The involvement of mitochondrial dysfunction in these diseases was reported, elicited by genetic alterations, exogenous toxins or buildup of toxic metabolites. In this review we shall discuss some metabolic alterations related to the pathophysiology of diseases with neurological involvement and aging process. These findings may help identifying early disease biomarkers and lead to more effective therapies to improve the quality of life of the patients affected by these devastating illnesses.
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Affiliation(s)
| | - Patrícia F Schuck
- Laboratory of inborn errors of metabolism, Universidade do Extremo Sul Catarinense, Brazil
| | - Gary L Wenk
- Department of Psychology, The Ohio State University, Columbus, OH 43210, USA
| | - Gustavo C Ferreira
- Laboratory of inborn errors of metabolism, Universidade do Extremo Sul Catarinense, Brazil
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15
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Duarte JM, Do KQ, Gruetter R. Longitudinal neurochemical modifications in the aging mouse brain measured in vivo by 1H magnetic resonance spectroscopy. Neurobiol Aging 2014; 35:1660-8. [DOI: 10.1016/j.neurobiolaging.2014.01.135] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 11/19/2013] [Accepted: 01/27/2014] [Indexed: 12/29/2022]
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Konsolaki E, Skaliora I. Premature Aging Phenotype in Mice Lacking High-Affinity Nicotinic Receptors: Region-Specific Changes in Layer V Pyramidal Cell Morphology. Cereb Cortex 2014; 25:2138-48. [PMID: 24554727 DOI: 10.1093/cercor/bhu019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The mechanisms by which aging leads to alterations in brain structure and cognitive deficits are unclear. Α deficient cholinergic system has been implicated as one of the main factors that could confer a heightened vulnerability to the aging process, and mice lacking high-affinity nicotinic receptors (β2(-/-)) have been proposed as an animal model of accelerated cognitive aging. To date, however, age-related changes in neuronal microanatomy have not been studied in these mice. In the present study, we examine the neuronal structure of yellow fluorescent protein (YFP(+)) layer V neurons in 2 cytoarchitectonically distinct cortical regions in wild-type (WT) and β2(-/-) animals. We find that (1) substantial morphological differences exist between YFP(+) cells of the anterior cingulate cortex (ACC) and primary visual cortex (V1), in both genotypes; (2) in WT animals, ACC cells are more susceptible to aging compared with cells in V1; and (3) β2 deletion is associated with a regionally and temporally specific increase in vulnerability to aging. ACC cells exhibit a prematurely aged phenotype already at 4-6 months, whereas V1 cells are spared in adulthood but strongly affected in old animals. Collectively, our data reveal region-specific synergistic effects of aging and genotype and suggest distinct vulnerabilities in V1 and ACC neurons.
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Affiliation(s)
- Eleni Konsolaki
- Neurophysiology Laboratory, Division of Developmental Biology, Biomedical Research Foundation of the Academy of Athens, Athens 115 27, Greece
| | - Irini Skaliora
- Neurophysiology Laboratory, Division of Developmental Biology, Biomedical Research Foundation of the Academy of Athens, Athens 115 27, Greece
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Peripheral deafferentation-driven functional somatosensory map shifts are associated with local, not large-scale dendritic structural plasticity. J Neurosci 2013; 33:9474-87. [PMID: 23719814 DOI: 10.1523/jneurosci.1032-13.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Long-term peripheral deafferentation induces representational map changes in the somatosensory cortex. It has been suggested that dendrites and axons structurally rearrange in such paradigms. However, the extent and process of this plasticity remains elusive. To more precisely quantify deafferentation-induced structural plasticity of excitatory cells we repeatedly imaged GFP-expressing L2/3 and L5 pyramidal dendrites in the mouse barrel cortex over months after the removal of a subset of the whisker follicles (FR), a procedure that completely and permanently removes whisker-sensory input. In the same mice we imaged whisker-evoked intrinsic optical signals (IOS) to assess functional cortical map changes. FR triggered the expansion of spared whisker IOS responses, whereas they remained unchanged over months in controls. The gross structure and orientation of apical dendrite tufts remained stable over a two-month period, both in controls and after deprivation. However, terminal branch tip dynamics were slightly reduced after FR, and the formation of new dendritic spines was increased in a cell-type and location-dependent manner. Together, our data suggest that peripheral nerve lesion-induced cortical map shifts do not depend on the large scale restructuring of dendritic arbors but are rather associated with local cell-type and position-dependent changes in dendritic synaptic connectivity.
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Pereira PA, Santos D, Neves J, Madeira MD, Paula-Barbosa MM. Nerve growth factor retrieves neuropeptide Y and cholinergic immunoreactivity in the nucleus accumbens of old rats. Neurobiol Aging 2013; 34:1988-95. [PMID: 23540942 DOI: 10.1016/j.neurobiolaging.2013.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 02/01/2013] [Accepted: 02/15/2013] [Indexed: 10/27/2022]
Abstract
The nucleus accumbens (NAc) contains high levels of neuropeptide Y (NPY), which is involved in the regulation of functions and behaviors that deteriorate with aging. We sought to determine if aging alters NPY expression in this nucleus and, in the affirmative, if those changes are attributable to the cholinergic innervation of the NAc. The total number and the somatic volume of NPY- and choline acetyltransferase-immunoreactive neurons, and the density of cholinergic varicosities were estimated in the NAc of adult (6 months old) and aged (24 months old) rats. In aged rats, the number of NPY neurons was reduced by 20% and their size was unaltered. The number of cholinergic neurons and the density of the cholinergic varicosities were unchanged, but their somas were hypertrophied. Nerve growth factor administration to aged rats further increased the volume of cholinergic neurons, augmented the density of the cholinergic varicosities, and reversed the age-related decrease in the number of NPY neurons. Our data show that the age-related changes in NPY levels in the NAc cannot be solely ascribed to the cholinergic innervation of the nucleus.
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Affiliation(s)
- Pedro A Pereira
- Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.
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Huffman K. The developing, aging neocortex: how genetics and epigenetics influence early developmental patterning and age-related change. Front Genet 2012; 3:212. [PMID: 23087707 PMCID: PMC3473232 DOI: 10.3389/fgene.2012.00212] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/26/2012] [Indexed: 11/13/2022] Open
Abstract
A hallmark of mammalian development is the generation of functional subdivisions within the nervous system. In humans, this regionalization creates a complex system that regulates behavior, cognition, memory, and emotion. During development, specification of neocortical tissue that leads to functional sensory and motor regions results from an interplay between cortically intrinsic, molecular processes, such as gene expression, and extrinsic processes regulated by sensory input. Cortical specification in mice occurs pre- and perinatally, when gene expression is robust and various anatomical distinctions are observed alongside an emergence of physiological function. After patterning, gene expression continues to shift and axonal connections mature into an adult form. The function of adult cortical gene expression may be to maintain neocortical subdivisions that were established during early patterning. As some changes in neocortical gene expression have been observed past early development into late adulthood, gene expression may also play a role in the altered neocortical function observed in age-related cognitive decline and brain dysfunction. This review provides a discussion of how neocortical gene expression and specific patterns of neocortical sensori-motor axonal connections develop and change throughout the lifespan of the animal. We posit that a role of neocortical gene expression in neocortex is to regulate plasticity mechanisms that impact critical periods for sensory and motor plasticity in aging. We describe results from several studies in aging brain that detail changes in gene expression that may relate to microstructural changes observed in brain anatomy. We discuss the role of altered glucocorticoid signaling in age-related cognitive and functional decline, as well as how aging in the brain may result from immune system activation. We describe how caloric restriction or reduction of oxidative stress may ameliorate effects of aging on the brain.
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Affiliation(s)
- Kelly Huffman
- Department of Psychology, University of California Riverside, CA, USA
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