ArticleNeuroscience2008
Synapses are lost during aging in the primate prefrontal cortex.
Article in Neuroscience, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 158 papers, 1 of them a synthesis that pooled it.
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Who cites it
158 citing papers in PubMed, 1 synthesis or guideline pooled it, 272 citations in OpenAlex.
- Cognitive Functioning of Unaffected First-degree Relatives of Individuals With Late-onset Alzheimer's Disease: A Systematic Literature Review and Meta-analysis.Neuropsychology review · 2023Pooled it
- Synaptic genes are extensively downregulated across multiple brain regions in normal human aging and Alzheimer's disease.Neurobiology of aging · 2013Trial
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- Higher physical activity levels mitigate synaptic protein loss and cognitive deterioration in aging and in Alzheimer's disease: a 10-year longitudinal study.Molecular biomedicine · 2026Article
- Synaptic Vesicle Disruption in Parkinson's Disease: Dual Roles of α-Synuclein and Emerging Therapeutic Targets.Brain sciences · 2025Review
- Neurochemical changes in GABA+, Glx, and the excitatory/inhibitory ratio in the calcarine cortex with healthy aging.NeuroImage · 2025Article
- The Drosophila escape motor circuit shows differential vulnerability to aging linked to functional decay.PLoS biology · 2025Article
- Axon collateralization and focal myelin dystrophy alter action potential propagation in multicompartment pyramidal neuron models.PLoS computational biology · 2025Article
- Molecular Mechanisms Behind Organ-Related Aging and Regulatory Effects of Natural Therapeutics.Cell biochemistry and biophysics · 2025Review
- Ryanodine receptor 2-mediated calcium leak is associated with increased glyoxalase I in the aging brain.JCI insight · 2025Article
- Single-cell, multi-region profiling of the macaque brain across the lifespan.bioRxiv : the preprint server for biology · 2025Article
- Gender-Dependent Cognitive and Metabolic Benefits Due to Glyoxalase 1 (Glo1) Overexpression in Age-Accelerated SAMP8 Mice.Antioxidants (Basel, Switzerland) · 2025Article
- Attention-dependent coupling with forebrain and brainstem neuromodulatory nuclei differs across the lifespan.GeroScience · 2025Article
- Synaptic vesicle-omics in mice captures signatures of aging and synucleinopathy.Nature communications · 2025Article
- Experimental modeling of Alzheimer's disease: Translational lessons from cross-taxon analyses.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2025Review
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- Mechanisms of astrocyte aging in reactivity and disease.Molecular neurodegeneration · 2025Review
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- Neuronal Synaptic Communication and Mitochondrial Energetics in Human Health and Disease.Advances in experimental medicine and biology · 2025Review
98 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
An electron microscopic analysis has been carried out on the effects of age on the numerical density of both excitatory (asymmetric) and inhibitory (symmetric) synapses in the neuropil of layers 2/3 and of layer 5 in area 46 from the frontal cortex of behaviorally tested rhesus monkeys. There is no change in the lengths of synaptic junctions with age or in the percentage distribution of synapses relative to the postsynaptic spines and dendritic shafts. However, in layers 2/3 there is an overall loss of about 30% of synapses from 5 to 30 years of age, and both asymmetric and symmetric synapses are lost at the same rate. In layer 5 the situation is different; the overall loss of synapses is only 20% and this is almost entirely due to a loss of asymmetric synapses, since there is no significant loss of symmetric synapses from this layer with age. When the synapse data are correlated with the overall cognitive impairment shown by the monkeys, it is found that there is a strong correlation between the numerical density of asymmetric synapses in layers 2/3 and cognitive impairment, with a weaker correlation between symmetric synapse loss and cognitive impairment. In layer 5 on the other hand there is no correlation between synapse loss and cognitive impairment. However synapse loss is not the only factor causing cognitive impairment, since in previous studies of area 46 we have found that age-related alteration in myelin in this frontal area also significantly contributes to cognitive decline. The synapse loss is also considered in light of earlier studies, which show that the frequency of spontaneous excitatory synaptic responses is reduced with age in layers 2/3 neurons.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.