Selective corticosteroid antagonists modulate specific aspects of spatial orientation learning.

TLDR

Mineralocorticoid and glucocorticoid receptors are densely distributed in the hippocampus, and spatial navigation is a sensitive measure of hippocampal function. The study examined corticosteroid effects on behavior in rats, using intracerebroventricular injections of selective MR and GR antagonists to probe their distinct roles in spatial learning. Adrenalectomy impaired spatial learning, while selective MR antagonism altered search‑escape strategies and selective GR antagonism after training increased platform‑finding latencies, indicating that corticosteroids differentially modulate spatial learning strategies and memory consolidation.

Abstract

Receptors for mineralocorticoids (MRs) and glucocorticoids (GRs) display a high concentration and distinct distribution in the hippocampus. The effects of corticosteroids on behavior mediated by central MRs and GRs were assessed in rats. Spatial navigation is considered to be a sensitive measure for hippocampal functioning. Removal of circulating corticosteroids (via adrenalectomy) impaired spatial learning. In intact rats, blockade of central MRs and GRs by intracerebroventricular injection of selective MR and GR antagonists influenced different aspects of spatial learning. The analysis of the behavioral pattern revealed that treatment with the MR antagonist altered search-escape strategies in the water maze. The injection of the GR antagonist after training resulted in increased latencies to find the platform, which reflects the disturbed consolidation of spatial information. Corticosteroids affect in a differential and coordinated manner behavioral strategies and storage of spatial information.