Inhibitory role of the serotonergic system on estrogen receptor α expression in the female rat hypothalamus.

The role of the serotonergic system in regulating the expression of estrogen receptor (ER) α in the hypothalamus was investigated in ovariectomized rats by injecting a serotonin synthesis inhibitor, parachlorophenylalanine (PCPA), or by destroying the dorsal raphe nucleus (DR). The number of ERα-immunoreactive (ir) cells was counted in the anteroventral periventricular nucleus in the preoptic area (AVPV), ventrolateral ventromedial hypothalamic nucleus (vlVMN), and arcuate nucleus (ARCN). Seven days after ovariectomy, 100mg/kg PCPA or saline was injected daily for 4 days.