Conditional Gdi1 Deletion on Synaptic Function Figure 3. Immunofluorescence analysis of Gdi1lox, Gdi1flox/Y and Gdi1-null mouse brain regions. Immunofluorescence analysis of 15 mm coronal sections of Gdi1lox/Y. Gdi1flox/Y and Gdi1-null. (A) Low magnification coronal section from Gdi1lox/Y brain indicating the regions of interest reported on the right: DG (dentate gyrus, B-B0 and F-F0), CA1 (hippocampal CA1 region, C-C0 and G-G0), LA (lateral amygdala, D-D0 and H-H0) and MGm (medial geniculate nucleus, E-E0 and I-I0). (A) Scale bar: 1 mm. (B–I0) Scale bar: 0.015 mm. doi:10.1371/journal.pone.0029763.g003 monosynaptic EPSC whose amplitude increases progressively with the stimulation intensity (Fig. 6B). At the maximal stimulation intensity - determined as not being noxious for the incoming fibers, evoked EPSC (eEPSC) amplitude reaches a maximal value (eEPSCmax, Fig. 6B). Interestingly, the input/output (I/O) relationships obtained in Gdi1 WT and Gdi1-null animals were different. Indeed, the first eEPSC was obtained at similar stimulation intensities, indicating that the AP-threshold may be similar in both genotypes, while the amplitude of the eEPSC at supra-threshold intensities was systematically lower in mice (at PLoS ONE | www.plosone.org 5 January 2012 | Volume 7 | Issue 1 | e29763