Title

Effects of Dehydroepiandrosterone Sulfate (DHEAS) and Stress on Hippocampal Electrophysiological Plasticity

Document Type

Article

Publication Date

1995

Digital Object Identifier (DOI)

https://doi.org/10.1111/j.1749-6632.1995.tb17393.x-i1

Abstract

Dehydroepiandrosterone sulfate (DHEAS) is the major secretory product of the human adrenal cortex, is described functionally as an ant glucocorticoid, and its levels decline with age.' Little is known, however, about the effects of DHEAS on CNS function. We studied the effects of DHEAS on hippocampal primed burst (PB) potentiation and long-term potentiation (LTP), two electrophysiological models of memory 24 in both cases, relatively brief electrical stimulation of the hippocampus induces a long-lasting enhancement of synaptic transmission which has characteristics in common with memory. However, whereas LTP involves extensive high frequency electrical stimulation (25-100 pulses) which typically induces a large increase in the magnitude of an evoked response, PB potentiation involves threshold stimulation (only 5 pulses patterned to mimic endogenous electrophysiological activity) and a smaller increase in In this work we evaluated the effects of the administration of DHEAS on the magnitude of hippocampal LTP and PB potentiation. Furthermore, we tested the hypothesis that stress will modulate DHEA-induced changes in PB potentiation and LTP. Young adult 350-g male Sprague-Dawley rats were injected with DHEAS (24 mg/kg, sc) or saline solution and then 10 minutes later were anesthetized with urethane (1.25 g/kg, ip). Subjects in a second group were stressed by placing them in an unfamiliar environment for 20 minute and were then injected with DHEAS and urethane. A stimulating electrode was placed in the ventral hippocampal commissure, and a recording electrode was placed in the CAI cell layer of the hippocampus, according to procedures described previously. Test pulses were delivered every 30 seconds for 10 minutes before and for 30 minutes after PB and LTP stimulation. Primed burst stimulation, composed of a single pulse followed 170

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Citation / Publisher Attribution

Annals of the New York Academy of Sciences: Dehydroepiandrosterone (DHEA) and Aging, v. 774, issue 1, p. 304-307

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