title: Serotonin regulates type II corticosteroid receptor binding in hippocampal cell cultures.
abstract: Previous work from our laboratory has shown that early postnatal handling of rat pups permanently increases hippocampal type II, but not type I, corticosteroid receptor binding. Handling also increases hippocampal 5-HT turnover, and the effect of handling on type II corticosteroid receptor binding is blocked by concurrent administration of the 5-HT2 receptor antagonist ketanserin. In view of these findings, the present studies examined the effects of 5-HT on type I ([3H]corticosterone) and type II ([3H]RU 28362) corticosteroid receptor binding in dispersed hippocampal cell cultures derived from animals killed at E19-20 in order to verify that 5-HT can act directly on hippocampal cells to alter corticosteroid receptor binding. Both type I and type II receptors were measurable in cultured hippocampal cells and the apparent affinity (Kd) for [3H]corticosterone (0.4 +/- 0.1 nM) and [3H]RU 28362 (0.8 +/- 0.1 nM) was similar to that from studies with intact animals. 5-HT increased type II, but not type I, corticosteroid receptor binding capacity in a dose-related manner, with the maximal effect (+188%) observed at 10 nM 5-HT and no change in the affinity of the receptor for [3H]RU 28362. The effect of 10 nM 5-HT on [3H]RU 28362 binding required a minimum of 4 d exposure and persisted for at least 7 d following the removal of 5-HT. The effect of 10 nM 5-HT on [3H]RU 28362 binding was completely blocked by the 5-HT2 receptor antagonists ketanserin and mianserin. There were no effects of the 5-HT1a antagonist, BMY 7378, or the 5-HT3 antagonist, MDL 72222.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Douglas Hospital Research Center, Department of Psychiatry, McGill University Montreal, Quebec, Canada.
authors.forename: J B
authors.initials: JB
authors.lastname: Mitchell
authors.forename: W
authors.initials: W
authors.lastname: Rowe
authors.forename: P
authors.initials: P
authors.lastname: Boksa
authors.forename: M J
authors.initials: MJ
authors.lastname: Meaney
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013997:Time Factors
chemical_list: D011965:Receptors, Glucocorticoid; D012702:Serotonin Antagonists; D012701:Serotonin