Histograms showing mean (±SEM) numbers of LH pulses detected over the 2-hour sampling period (A and B) and mean (±SEM) LH pulse amplitudes (C and D) of metestrous (M), diestrous (D), proestrous (P), estrous (E), OVX, and OVX+E mice. In panel B, the diestrous data are replotted on a different scale. Bars with different letters are significantly different from one another (see text; one way ANOVA with post hoc Tukey’s tests). Numbers at the base of each bar indicate animal N numbers. Note that the N for estrous mice in C is 7 because only 7 of 18 mice exhibited LH pulses.