Estrogen administration increases neuronal responses to excitatory amino acids as a long-term effect

Ongoing studies from this laboratory have demonstrated marked potentiating actions of the sex steroid 17 beta-estradiol (E2) on glutamate-induced excitation. In the present study, systemic injection of a physiological dose of E2 was demonstrated to augment significantly excitatory responses of cerebellar Purkinje (Pnj) cells to iontophoretic application of the specific excitatory amino acid (e.a.a.) agonists quisqualate and N-methyl-D-aspartate. Potentiation of e.a.a. responses was observed as rapidly as 5-10 min post E2, and was, in many cases, a persistent, non-decremental effect. These observed long-term actions of E2 may provide one mechanism for the activating effects of the steroid on sensorimotor function and seizure activity.