Female rats show an increased sensibility to the forced swim test depressive-like stimulus in the hippocampus and frontal cortex 5-HT1A receptors.

Affective disorders are more common in women. The forced swim test acts like a depressive stimulus. Hippocampus and frontal cortex 5-HT1A receptors of female and male Wistar rats subjected to the forced swim test were compared with a sham group. The forced swim test diminishes (P<0.05) the hippocampus 3H-8OH-DPAT bound in the female rats (184+/-16 fmol/mg protein) with respect to the male rats (309+/-41 fmol/mg protein) and to the female sham rats (255+/-20 fmol/mg protein). The forced swim test increases the frontal cortex 5-HT1A receptors in the female rats with respect to the female sham group (40.4+/-5 versus 24.7+/-4 fmol/mg protein, P<0.05). An increased sensibility of the 5-HT1A receptors to depressive-stimulus may be one mechanism underlying the higher prevalence of depression in female.