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Effects of glucocorticoids on hippocampal long‐term potentiation
Author(s) -
Pavlides Constantine,
Watanabe Yoshifumi,
McEwen Bruce S.
Publication year - 1993
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.450030210
Subject(s) - long term potentiation , dentate gyrus , excitatory postsynaptic potential , hippocampal formation , corticosterone , population spike , ltp induction , medicine , chemistry , postsynaptic potential , endocrinology , hippocampus , electrophysiology , granule cell , neuroscience , psychology , inhibitory postsynaptic potential , receptor , hormone
The effects of chronic and acute corticosterone (CORT) administration were investigated on hippocampal long‐term potentiation (LTP) in the dentate gyrus granule cell layer of the rat. Electrophysiological experiments were performed in vivo under urethane anesthesia. Chronic CORT treatment (40 mg/kg/day) over 21 days decreased LTP compared to vehicle controls, even when LTP was measured 48 hours after cessation of CORT treatment, when serum CORT levels had returned to baseline. A single injection of CORT also decreased LTP compared to vehicle controls, but only when CORT levels were high, since at 48 hours after a single acute CORT injection LTP was not depressed. The decrements in LTP were seen both for the slope of the excitatory postsynaptic potential and for the population spike. Yet CORT had no effects on posttetanic potentiation or neuronal excitability. These findings are consistent with previous reports showing a reduction in LTP in the CAI field of animals exposed to stress or acute CORT administration.