Abstract
Down's syndrome (DS) individuals develop neuropathological features similar to Alzheimer's disease (AD), including degeneration of cholinergic basal forebrain (CBF) neurons. In AD a reduction in CBF/trkA-containing neurons has been suggested to trigger a hyperexpression of galaninergic fibers within the nucleus basalis subfield of the basal forebrain. The present study examined the interrelationship between reductions in CBF/trkA- containing neurons and the overexpression of galaninergic fibers within the nucleus basalis in DS. Within the nucleus basalis stereologic evaluation revealed a 46% reduction in the number of trkA-immunopositive neurons, whereas optical density measurements d splayed a nonsignificant 18% reduction in neuronal trkA immunoreactivity in DS as compared with age-matched controls. Western blot analysis also showed a significant reduction in cortical trkA protein levels in DS. A semiquantitative examination of galaninergic fibers in the nucleus basalis revealed only a modest hypertrophy of galaninergic fibers within the nucleus basalis in DS. The present findings indicate a significant reduction in trkA within the nucleus basalis and cortex with only a moderate hypertrophy of galaninergic fibers in DS. These observations suggest that DS may not be an exact genetic model for investigation of changes in the AD basal forebrain.
Original language | English (US) |
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Pages (from-to) | 1185-1196 |
Number of pages | 12 |
Journal | Journal of Neurochemistry |
Volume | 74 |
Issue number | 3 |
DOIs | |
State | Published - 2000 |
Externally published | Yes |
Keywords
- Alzheimer's disease
- Cholinergic basal forebrain neurons
- Down's syndrome
- Galaninergic fibers
- Nucleus basalis
- TrkA-immunoreactive neurons
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience