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Updated: Jul 6, 2026
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Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology
Published on: March 23, 2011
Synapses are lost during aging in the primate prefrontal cortex
A Peters1, C Sethares, J I Luebke
1Department of Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118-2526, USA. apeteres@cajal-1.bu.edu
Neuroscience
|March 11, 2008
Summary
Aging reduces synapse numbers in the frontal cortex, particularly asymmetric synapses in layers 2/3, correlating with cognitive decline in rhesus monkeys.
Area of Science:
- Neuroscience
- Aging Research
- Cognitive Science
Background:
- Synaptic density changes with age, potentially impacting cognitive function.
- Area 46 of the frontal cortex is crucial for cognitive processes.
- Previous research indicates age-related myelin alterations also contribute to cognitive decline.
Purpose of the Study:
- To investigate the effects of aging on excitatory and inhibitory synapse numerical density in rhesus monkey frontal cortex.
- To correlate age-related synaptic changes with cognitive impairment.
- To compare synaptic changes in different cortical layers (2/3 vs. 5).
Main Methods:
- Electron microscopic analysis of synapses in area 46 of rhesus monkey frontal cortex.
- Behavioral testing to assess cognitive function.
- Correlation analysis between synaptic density and cognitive impairment scores.
Main Results:
- A 30% loss of synapses in layers 2/3 and a 20% loss in layer 5 with age.
- Asymmetric synapses were primarily lost in layer 5, while both types were lost in layers 2/3.
- Strong correlation between asymmetric synapse loss in layers 2/3 and cognitive impairment.
Conclusions:
- Age-related synapse loss, especially asymmetric synapses in superficial layers, contributes to cognitive decline.
- Synaptic changes in layer 5 show less correlation with cognitive impairment.
- Cognitive impairment is multifactorial, involving both synaptic and myelin alterations.
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