Cycle stage | Maximum population spike amplitude (mV) | ES50 (μsec) |
---|---|---|
Proestrus (n = 17 slices) | 12.0 ± 0.9* | 67.8 ± 6.7 |
Estrus (n = 8) | 13.7 ± 0.3* | 28.8 ± 0.8** |
Metestrus (n = 9) | 7.03 ± 0.81 | 75.1 ± 10.9 |
The data in Figure 3 were subjected to nonlinear least-squares curve-fitting analysis, relating the CA1 population spike amplitude to the duration of the input stimulus using a four-parameter logistic function (see Materials and Methods). For each stage of the cycle, estimates were determined for the maximal population spike amplitude and the ES50 value (stimulus duration required to obtain a 50% maximal CA1 spike). Data are presented as the 'best fit' parameter estimates, together with their associated variances (expressed as SE of the mean) calculated from the regression analysis (DeLean et al, 1978). Statistical analysis, based on analysis of residual variance: *p < 0.0001 compared with data in slices from animals at metestrus; **p < 0.0001 compared with data in slices from animals at proestrus and metestrus.