Examination of estradiol effects on the rapid estradiol mediated increase in hippocampal synaptic transmission in estrogen receptor alpha knockout mice.

Hippocampal slices from rats exhibit a rapid increase in basal synaptic transmission following 17 beta-estradiol (E(2)) application. In the current study we examined the role of the classic genomic receptor, estrogen receptor alpha (ER alpha), in mediating E(2) effects on synaptic transmission. E(2) (100 pM) increased the extracellular synaptic response in hippocampal slices from gonadectomized male and female mice lacking a functional ER alpha knockout (ER alpha KO) and wild-type (WT) littermates. No sexually dimorphic differences were observed, however, the increase in the field potential was more pronounced in WT mice. ER antagonists did not block E(2) mediated growth of the synaptic response in ER alpha KO mice. The results suggest that the rapid effect of E(2) on synaptic transmission is not mediated by ER alpha, however, ER alpha appears to modulate non-genomic influences on synaptic transmission.