Estradiol directly modulates sodium currents, but not DAPs, in GnRH neurons from aged animals. (A) Mean AM current density is significantly decreased by estradiol treatment in GnRH neurons from aged animals (*, p = 0.02, n = 9–10). Upper traces represent overlaid currents (average of 10 records, 11–12 pF) from a control or estradiol-treated neuron isolated from a 13-month old (aged) animal. (B) The width at half-maximum sodium current amplitude is significantly increased by estradiol treatment in aged animals (*, p < 0.001; n = 9–10). A similar result is seen in young animals (Figure 5D). (C) Estradiol application to cells from aged animals has no effect on DAP amplitude in AM recordings (n = 6–8). The legend in (A) applies to all graphs.