Temporal modulation of hippocampal excitatory transmission by corticosteroids and stress
Frontiers in Neuroendocrinology. 2011-01-01; 32(1): 25-42
DOI: 10.1016/j.yfrne.2010.07.004
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There is overwhelming evidence for multiple effects of stress on excitatory
transmission and synaptic plasticity in the hippocampus. These interactions
between stress and hippocampal glutamatergic neurons play a role in the cognitive
and emotional consequences of aversive stimuli. Stress impacts on excitatory
synapses are mediated by a complex set of neurohormones and neurotransmitters,
among which corticosteroid hormones secreted from the adrenal cortex play a
crucial role. Most effects of corticosteroid hormones are mediated by their
binding to cytosolic mineralocorticoid (MR) and glucocorticoid receptors (GR),
which after translocation to the nucleus, regulate the transcription of target
genes. Recent electrophysiological and live imaging experiments have however
provided experimental data which reinforce the hypothesis that beside these
delayed effects, corticosteroid hormones may also act rapidly through membrane
receptors. The first goal of this review is to detail the tonic and intrinsic
effects of corticosteroid hormones on hippocampal excitatory transmission,
glutamate receptor trafficking and expression, and synaptic plasticity, paying
attention to their temporality (rapid and transient effects followed by slow and
persistent genomic effects). Its second goal is to dissect the extent to which
acute/repeated stress influences hippocampal excitatory synapses and whether
these are accounted for by corticosteroid hormones.
Copyright © 2010 Elsevier Inc. All rights reserved.