Subcutaneous injection of E2 (320 µg/kg) in ovariectomized rats significantly increased phosphorylation of A) CaMKII, B) ERK, and C) GluR1, 6 hrs after injection (227 ± 37%, 316 ± 36%, and 353 ± 116%, respectively), and all returned to their respective basal levels at 24 hrs. Data are mean ± SD. *, p<0.05, **, p<0.01, ***, p<0.001, versus time 0 or groups connected by bars as determined by one-way ANOVA followed by Newman- Keuls Multiple Comparison Test, n=3 (3 independent experiments).