By means of transmission electron microscopy, the age-related changes in axospinous (ASS) and axodendritic (ADS) synapses in the dorsal part of the rostral neostriatum in two groups of Wistar rats: young (3-month-old), and senescent (25-month-old) were examined. The changes in different parameters, characterizing the ASS and ADS: synaptic density (SD), number of synaptic vesicles (SV), number of synaptic contact zone (SCZ), and number of dendritic spines, bearing synapses (DS) were investigated morphometrically. The SD of the ASS decreased significantly during aging, but the SD of the ADS did not changed significantly. The mean area of the synaptic boutons increased significantly during aging in two types of synapses. The mean number of vesicles per synaptic bouton increased, but the number of vesicles per microm2 of synaptic bouton, and per microm3 of the neuropil decreased. The mean SCZ length increased in both types of synapses. The total SCZ length per 1000 microm2 of the neuropil, and the total area of the SCZ per 1000 microm3 of the neuropil decreased in ASS, but the same parameters of the ADS did not changed significantly. The mean number of synaptic DS per 1000 microm2 of the neropil decreased during aging, but the mean area of the synaptic DS increased. The present results support the hypothesis that the synaptic contacts change significantly during aging, and the ASS are more vulnerable during aging than the ADS.
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http://dx.doi.org/10.1076/apab.109.1.80.4279 | DOI Listing |
J Neurosci
January 2025
Laboratory of Cerebral Cortex Research, HUN-REN Institute of Experimental Medicine, Budapest, Hungary
The human hippocampus, essential for learning and memory, is implicated in numerous neurological and psychiatric disorders, each linked to specific neuronal subpopulations. Advancing our understanding of hippocampal function requires computational models grounded in precise quantitative neuronal data. While extensive data exist on the neuronal composition and synaptic architecture of the rodent hippocampus, analogous quantitative data for the human hippocampus remain very limited.
View Article and Find Full Text PDFJ Physiol
January 2025
Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.
Synaptic vesicle (SV) trafficking toward the plasma membrane (PM) and subsequent SV maturation are essential for neurotransmitter release. These processes, including SV docking and priming, are co-ordinated by various proteins, such as SNAREs, Munc13 and synaptotagmin (Syt), which connect (tether) the SV to the PM. Here, we investigated how tethers of varying lengths mediate SV docking using a simplified mathematical model.
View Article and Find Full Text PDFJ Pharm Anal
December 2024
Laboratory of Neuropharmacology, EBRI Rita Levi-Montalcini Foundation, Rome, 00161, Italy.
A wide number of natural molecules demonstrated neuroprotective effects on synaptic plasticity defects induced by amyloid-β (Aβ) in and Alzheimer's disease (AD) models, suggesting a possible use in the treatment of this neurodegenerative disorder. However, several compounds, administered parenterally and orally, are unable to reach the brain due to the presence of the blood-brain barrier (BBB) which prevents the passage of external substances, such as proteins, peptides, or phytocompounds, representing a limit to the development of treatment for neurodegenerative diseases, such as AD. The combination of nano vesicular systems, as colloidal systems, and nose to brain (NtB) delivery depicts a new nanotechnological strategy to overtake this limit and to develop new treatment approaches for brain diseases, including the use of natural molecules in combination therapy for AD.
View Article and Find Full Text PDFNeurobiol Stress
January 2025
Department of Translational Neuroscience, Wake Forest University, School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
With the recent rise in the rate of alcohol use disorder (AUD) in women, the historical gap between men and women living with this condition is narrowing. While there are many commonalities in how men and women are impacted by AUD, an accumulating body of evidence is revealing sex-dependent adaptations that may require distinct therapeutic approaches. Preclinical rodent studies are beginning to shed light on sex differences in the effects of chronic alcohol exposure on synaptic activity in a number of brain regions.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory of Mental Disorders, The Second Hospital of Shandong University, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China.
Major depressive disorder (MDD) is usually considered associate with immune inflammation and synaptic injury within specific brain regions. However, the molecular mechanisms underlying the neural deterioration resulting in depression remain unclear. Here, it is found that miR-204-5p is markedly downregulated in the ventromedial prefrontal cortex (vmPFC) in a chronic unpredictable mild stress (CUMS) induce rat model of depression.
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