Figure 2.

Medium spiny neuron (MSN) action potential (AP) firing rates evoked by depolarizing current injections vary by sex and perinatal exposure to estradiol. A: voltage response of an MSN to a series of depolarization current injections, recorded from a male with perinatal exposure to vehicle. “−74 mV” indicates resting membrane potential. B: AP firing rate evoked by depolarizing current injection. AP firing rate was decreased in MSNs recorded from males compared to females with perinatal exposure to vehicle. AP firing rate was masculinized in MSNs recorded from females with perinatal exposure to estradiol. MSNs recorded from males with perinatal exposure to estradiol exhibited increased AP firing rate compared to males with perinatal exposure to vehicle. C: the slope of the evoked AP firing rate to depolarizing current injection curve (FI Slope) is decreased in males with perinatal exposure to vehicle and females with perinatal exposure to estradiol compared to females with perinatal exposure to vehicle and males with perinatal exposure to estradiol. D: mean initial firing rate (the reciprocal of the 1st interspike interval) is decreased in MSNs recorded from males with perinatal exposure to vehicle and females with perinatal exposure to estradiol compared to females with perinatal exposure to vehicle and males with perinatal exposure to estradiol. E: mean steady-state firing rate (mean firing rate over the last 300 ms of the current injection) is decreased in MSNs recorded from males with perinatal exposure to vehicle and females with perinatal exposure to estradiol compared to females with perinatal exposure to vehicle and males with perinatal exposure to estradiol. FI slope: slope of the evoked action potential to depolarizing current injection curve. #P = 0.0802; *P < 0.05; **P < 0.01.