Aging is associated with divergent effects on Nf-L and GFAP transcription in rat brain.

We studied the effects of advancing age on the expression of several proteins important in the structure and function of the nervous system. Brains of young (3 month), middle-aged (13 month), and old (29 month) male Fischer 344 rats were examined. Run-on transcription and Northern blot hybridizations were used to determine gene-specific transcription rates and mRNA levels, respectively.

Reductions in motoneuronal neurofilament synthesis by successive axotomies: a possible explanation for the conditioning lesion effect on axon regeneration.

Axons regenerate more rapidly after a test lesion if they received a conditioning lesion. Previous work suggests that the cell body reaction to injury is responsible for this conditioning lesion effect. Here we examined the effects of the second, test lesion on the expression of the major cytoskeletal proteins, tubulin, actin, and neurofilament proteins.

Attenuation and recovery of nerve growth factor receptor mRNA in dorsal root ganglion neurons following axotomy.

The actions of nerve growth factor (NGF) are mediated by two receptor proteins, trk and p75. Recent evidence indicates that NGF upregulates the expression of both trk and p75 in responsive neurons including rat dorsal root ganglion (DRG) neurons. Axotomy by disconnecting the neuron from its source of target-derived NGF is predicted to lead to the downregulation of trk and p75 expression.

Axonal atrophy in aging is associated with a decline in neurofilament gene expression.

Neurofilaments (Nfs) are major determinants of axonal caliber. Nf transcript levels increase during development and maturation, and are associated with an increase in Nf protein, Nf numbers, and caliber of axons. With aging there is axonal atrophy.

Cognitive impairment in the nondemented elderly. Results from the Canadian Study of Health and Aging.

Study Objective: To describe a population that was categorized as "cognitively impaired not demented" (CIND) and to examine the utility of some of the proposed criteria for describing this degree of cognitive impairment.

Design: Population-based prevalence study of dementia in those subjects who were 65 years and older.

Setting: Community and institutional settings in Canada.