Serotonin receptor 5-HT5A in rat hippocampus decrease by leptin treatment

Hydroxytryptamine (5-HT) is involved in a variety of different physiological processes and behaviors through the activation of equally diverse receptors subtypes. In this work we studied the changes on the expression of 5-HT5A receptors in rat hippocampus induced by leptin, an adipocyte-derived hor- mone that has been reported to participate in the modulation of food intake and in adult hippocampal neurogenesis. To study the effect of leptin on the 5-HT5A receptor gene expression a qRT-PCR was used and the distribution of those receptors in the hippocampus was visualized by immunohistochemistry. Rats were separated in four groups: control (untreated rats), leptin-treated, serotonin-treated and lep- tin + serotonin treated. The results showed that even though the 5-HT5A gene expression did not change in the hippocampus of any of the treated groups, in the rats treated with leptin and serotonin, the specific immunostaining for the 5-HT5A serotonin receptor decreased significantly in the dentate gyrus. © 2010 Elsevier Ireland Ltd. All rights reserved.