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 tra nsmission following 17 beta -estradiol (E-2) application. In the current st udy 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 kno ckout (ER alpha KO) and wild-type (WT) littermates. No sexually dimorphic d ifferences were observed, however, the increase in the field potential was more pronounced in WT mice. ER antagonists did not block E-2 mediated growt h of the synaptic response in ERaKO mice. The results suggest that the rapi d effect of E-2 on synaptic transmission is not mediated by ER alpha, howev er, ER alpha appears to modulate non-genomic influences on synaptic transmi ssion. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.