Abstract
We examined Fisher 344 female rats aged 6, 27, and 33 months old. Prior to sacrifice and morphometric analyses of forebrain cholinergic neurons all rats underwent behavioral characterization in a spatial learning task using the Morris water maze. Performance on the spatial task permitted subsequent grouping of the 27- and 33-month-old animals into impaired groups. Importantly, the percentage of animals that displayed spatial impairments increased sharply with advancing age. Quantitative assessment of the size and density of choline acetyltransferase (ChAT) - positive neurons throughout the basal forebrain revealed a significant enlargement of forebrain cholinergic neurons within 27-month-old nonimpaired rats compared to 6-month-old rats and 27- and 33-month-old impaired animals. This increase in size was most noted in the medial septum and nucleus of the diagonal band. Significant decreases in the density of ChAT-positive neurons was observed only in the nucleus of the diagonal band of 27-month-old impaired rats compared to 6-month-old controls. Although the significance of enlarged forebrain cholinergic neurons is unclear, we discuss the possibility that within aged rodents neuronal swelling is an active event and represents an early manifestation of the aging process and may constitute a restorative and/or compensatory event in that these rats are relatively asymptomatic with respect to their behavioral deficits. In addition, we discuss in some detail various technical and life effect issues which may vary the outcome of investigations of aged rodents.
Original language | English |
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Pages (from-to) | 457-470 |
Number of pages | 14 |
Journal | Neurobiology of Aging |
Volume | 14 |
Issue number | 5 |
DOIs | |
State | Published - 1993 |
Bibliographical note
Funding Information:This work supportbeyd N IH Grants AG05344, AG08206, AG06088, theP EW Foundation, and Athlzeh eimer'Dsi sease and Related Disorders Association.
Funding
This work supportbeyd N IH Grants AG05344, AG08206, AG06088, theP EW Foundation, and Athlzeh eimer'Dsi sease and Related Disorders Association.
Funders | Funder number |
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Greek Association of Alzheimer's Disease and Related Disorders | |
National Institute on Aging | R01AG006088 |
theP EW Foundation |
Keywords
- Aged rats
- Basal forebrain
- Choline acetyltransferase
- Morphology
- Nerve growth factor receptor
ASJC Scopus subject areas
- Clinical Neurology
- Geriatrics and Gerontology
- Aging
- General Neuroscience
- Developmental Biology