Fig. 3

Whole cell patch clamp recordings showed that Piriform Cortex (PC) layer II neurons from Fmr 1 KO mice are hyperexcitated compared to WT control. (A) Confocal fluorescent microphotography of a biocytin-labeled neuron recorded in layer II of the PC from a brain slice of a Fmr1 KO mouse. The nuclei from surrounding cells are stained with DAPI. (B) Representative whole-cell current-clamp recordings in response to a current pulse of 125 pA (blue traces) of neurons from WT (black) and Fmr1 KO (red) mice. (C) Firing frequency in response to increasing current steps from WT (black circles) and Fmr1 KO (red squares) neurons, starting from a holding voltage of -85 ± 2.5 mV. For both groups, n = 12. Light colors represent individual cells while bold colors show the average firing frequency vs. current curves of WT and Fmr1 KO cells. Two-way ANOVA results: strain factor p < 0.0001; current factor p < 0.0001; interaction: p = 0.0212. Sidak’s multiple comparison (*: p < 0.05, **: p < 0.01; ***: p < 0.0001). (D) Rheobase of WT and Fmr1 KO neurons obtained from the intercept with the X axis of each firing frequency curve shown in B. (E) Firing frequency slope of the linear segment of each curve shown in B. Here, and in all following figures, middle horizontal line and bars correspond to the mean and S.E.M respectively. All the upcoming figures follow the same color scheme used here, where black represents data from WT cells and red from Fmr1 KO cells