Abstract
Alterations in the basal forebrain cholinergic system have been widely studied in brain aging and Alzheimer's disease, but the magnitude of decline and relationship to cognitive impairment are still a matter of debate. The rhesus monkey (Macaca mulatta) provides a compelling model to study age-related memory decline, as the pattern of impairment closely parallels that observed in humans. Here, we used antibodies against the vesicular acetylcholine transporter and a new stereological technique to estimate total cholinergic fiber length in hippocampal subregions of behaviorally characterized young and aged rhesus monkeys. The analysis revealed an age-related decline in the length of cholinergic fibers of 22%, which was similar across the hippocampal subregions studied (dentate gyrus granule cell and molecular layers, CA2/3-hilus, and CA1), and across the rostral-caudal extent of the hippocampus. This effect, however, was unrelated to performance on the delayed nonmatching-to-sample task, a test of recognition memory sensitive to hippocampal system dysfunction and cognitive aging in monkeys. These findings indicate that a decline in cholinergic input fails to account for the influence of normal aging on memory supported by the primate hippocampal region.
Original language | English (US) |
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Pages (from-to) | 238-246 |
Number of pages | 9 |
Journal | Journal of Comparative Neurology |
Volume | 475 |
Issue number | 2 |
DOIs | |
State | Published - Jul 19 2004 |
Keywords
- Acetylcholine
- Aging
- Cognition
- Hippocampus
- Nonhuman primate
- Stereology
- Terms
ASJC Scopus subject areas
- Neuroscience(all)