Corticosteroids regulate brain hippocampal 5-HT1A receptor mRNA expression

• Published in: The Journal of neuroscience Vol. 13; no. 3; pp. 914 - 923
• Main Authors: Chalmers, DT, Kwak, SP, Mansour, A, Akil, H, Watson, SJ
• Format: Journal Article
• Language: English
• Published: Washington, DC Soc Neuroscience 01.03.1993; Society for Neuroscience
• Subjects: 8-Hydroxy-2-(di-n-propylamino)tetralin - metabolism; Adrenal Glands - physiology; Adrenalectomy; Analysis of Variance; Animals; Biological and medical sciences; Cell Membrane - metabolism; Cell receptors; Cell structures and functions; Corticosterone - pharmacology; Fundamental and applied biological sciences. Psychology; Hippocampus - drug effects; Hippocampus - physiology; In Situ Hybridization; Male; Molecular and cellular biology; Monoamines receptors (catecholamine, serotonine, histamine, acetylcholine); Pyramidal Tracts - physiology; Rats; Rats, Sprague-Dawley; Receptors, Serotonin - genetics; Receptors, Serotonin - metabolism; Reference Values; RNA, Messenger - analysis; RNA, Messenger - metabolism; Transcription, Genetic; Tritium; Corticosteroid; Rat; Rodentia; Central nervous system; Gene expression; Vertebrata; Mammalia; Messenger RNA; Adrenal hormone; Hormonal regulation; S1A receptor; Hippocampus; Brain (vertebrata)
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/jneurosci.13-03-00914.1993

Using in situ hybridization techniques, the expression of 5-HT1A receptor mRNA was measured within the hippocampal formation after bilateral adrenalectomy (ADX). After 24 hr ADX, 5-HT1A receptor mRNA expression was significantly increased in all hippocampal subfields in ADX animals relative to sham-operated controls (SHAM). The magnitude of the increase was most pronounced within CA2 (127%) and CA3/4 (94%)-subfields of dorsal hippocampus, intermediate in the dentate gyrus (73%), and least within CA1 (60%). Administration of exogenous corticosterone (CORT) at the time of ADX maintained the level of 5-HT1A receptor mRNA expression within the range of SHAM animals. In vitro receptor autoradiographic analysis of 5-HT1A receptors in adjacent sections from the same animals indicated a simultaneous increase in 5-HT1A binding throughout the hippocampus in response to ADX. 5-HT1A binding increased to a similar extent (approximately 30%) in CA subfields and dentate gyrus but remained within SHAM levels in CORT-replaced animals. 5-HT1A receptor mRNA levels were also increased in hippocampal subregions of 1 week ADX animals relative to SHAM animals. Within both CA1 and CA2 subfields, the increments were approximately double those observed after 1 d ADX. 5-HT1A receptor binding was increased in every hippocampal subfield to a similar extent as that observed after 1 d ADX. Increases in both 5-HT1A receptor mRNA expression and 5-HT1A receptor binding were preventable by administration of exogenous CORT at the time of ADX. Hippocampal 5-HT1C receptor mRNA and D1 receptor mRNA expression were not significantly altered by either acute or chronic ADX treatment. These data indicate that adrenal steroids may selectively regulate hippocampal 5-HT1A receptors at the level of 5-HT1A receptor mRNA expression.