DMCA
Membrane Mineralocorticoid but not Glucocorticoid Receptors of the Dorsal Hippocampus Mediate the Rapid Effects of Corticosterone on Memory Retrieval
BibTeX
@MISC{Dorey_membranemineralocorticoid,
author = {Rodolphe Dorey and Christophe Piérard and Svitlana Shinkaruk and Christophe Tronche and Frédéric Chauveau and Mathieu Baudonnat and Daniel Béracochéa and U Inserm Physiopathologie},
title = {Membrane Mineralocorticoid but not Glucocorticoid Receptors of the Dorsal Hippocampus Mediate the Rapid Effects of Corticosterone on Memory Retrieval},
year = {}
}
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Abstract
This study was aimed at determining the type of the glucocorticoid membrane receptors (mineralocorticoid receptors (MRs) or glucocorticoid receptors (GRs)) in the dorsal hippocampus (dHPC) involved in the rapid effects of corticosterone or stress on memory retrieval. For that purpose, we synthesized corticosterone–3-O-carboxymethyloxime–bovine serum albumin conjugate (Cort–3CMO– BSA) conjugate (a high MW complex that cannot cross the cell membrane) totally devoid of free corticosterone, stable in physiological conditions. In a first experiment, we evidenced that an acute stress (electric footshocks) induced both a dHPC corticosterone rise measured by microdialysis and memory retrieval impairment on delayed alternation task. Both the endocrinal and cognitive effects of stress were blocked by metyrapone (a corticosterone synthesis inhibitor). In a second experiment, we showed that bilateral injections of either corticosterone or Cort–3CMO–BSA in dHPC 15 min before memory testing produced impairments similar to those resulting from acute stress. Furthermore, we showed that anisomycin (a protein synthesis inhibitor) failed to block the deleterious effect of Cort– 3CMO–BSA on memory. In a third experiment, we evidenced that intra-hippocampal injection of RU-28318 (MR antagonist) but not of RU-38486 (GR antagonist) totally blocked the Cort–3CMO–BSA-induced memory retrieval deficit. In a fourth experiment, we demonstrated that RU-28318 administered 15 min before stress blocked the stress-induced memory impairments when behavioral
Keyphrases
memory retrieval glucocorticoid receptor rapid effect dorsal hippocampus mediate membrane mineralocorticoid acute stress corticosterone synthesis inhibitor gr antagonist physiological condition cognitive effect cell membrane mineralocorticoid receptor glucocorticoid membrane receptor stress-induced memory impairment second experiment memory retrieval impairment high mw complex bsa-induced memory retrieval deficit bilateral injection deleterious effect memory testing first experiment free corticosterone electric footshocks delayed alternation task mr antagonist dorsal hippocampus third experiment protein synthesis inhibitor intra-hippocampal injection fourth experiment dhpc corticosterone rise
