Biomedical subjects

M A Raskind

Publications and source records attributed to M A Raskind.

129 records · Page 8Linked to original sources

PubMedDate not supplied

The neurobiology of aging: does it predispose to depression?

This review examines the various research approaches undertaken to investigate possible central nervous system correlates of major depressive illness and relates findings from these studies to the alterations in central nervous system and neuroendocrine function that normally accompany aging in humans. The topics reviewed include: epidemiology of depression and suicide in the elderly; monoamine theories of depression; neuroendocrine disturbances in depression; and imaging studies.

Aged↗

PubMedDate not supplied

Galanin receptors in the hippocampus and entorhinal cortex of aged Fischer 344 male rats.

Galanin (GAL) has been proposed to be an inhibitory modulator of cholinergic memory pathways because it acts within the hippocampus to inhibit the release and antagonize the postsynaptic actions of acetylcholine. Here we have used: 1) slice binding and quantitative autoradiography to assess the density and occupancy of GAL receptors; and 2) in situ hybridization histochemistry to assess expression of the GALR1 receptor subtype in the ventral hippocampus of 3-month-old and 21-month-old Fischer 344 male rats. We detected a small but significant (p < or = 0.0003) age-related reduction in 125I-GAL binding-site density in the ventral hippocampus and entorhinal cortex under standard binding conditions. Post-hoc analysis indicated that this reduction with age persisted in the CA1 radiatum and entorhinal cortex following GTP-induced desaturation to unmask pre-existent GAL receptors occupied by endogenous ligand. It was not associated with a significant change in peak GALR1 gene expression in the hippocampus. Because a portion of GAL receptors in this region have been postulated to function as presynaptic auto-receptors on cholinergic fiber terminals, the reduction in GAL binding sites with age may be a consequence of age-related alterations in GAL receptor expression by basal forebrain cholinergic neurons which project to the ventral hippocampus.

Aging↗

PubMedDate not supplied

Effects of advanced aging on plasma catecholamine responses to the cold pressor test.

Increased basal norepinephrine (NE) concentrations have been demonstrated repeatedly in human aging, but these studies have included almost exclusively "early aging" subjects younger than age 75. We asked if "advanced aging" (over age 80) enhanced the effects of early aging on plasma NE and epinephrine (EPI) concentrations at rest and in response to the cold pressor test (CPT). Eight medically well, cognitively intact advanced aging subjects (84.4+/-0.9 years), 28 medically well cognitively intact early aging subjects (70.3+/-1.3 years), and 19 medically well young subjects (25.4+/-0.9 years) were studied. Both basal NE and the acute NE increase after CPT were significantly higher in advanced aging than in either early aging or young subjects. Plasma EPI concentrations were higher in the advanced aging group than in the other groups and an acute plasma EPI increase after CPT occurred only in the advanced aging group. These results suggest specific effects of advanced aging on both the sympathoneural and sympathoadrenomedullary components of the sympathetic nervous system.

Adult↗