Modes of intrinsic PC firing correlate with differential expression profiles of EAAT4. (A) Left, mid-sagittal cerebellar section from a fluorescent reporter BAC mouse in which eGFP (green) cDNA is under the control of the EAAT4 promoter. Bar, 500 µm. Right, coronal cerebellar sections from WT-eGFP (green) reporter mouse immunostained for either aldolase C (red) or EAAT4 (red). Bar, 50 µm. (B) Immunoblot analyses of EAAT protein levels in cerebellar homogenates from WT, WT-eGFP and ET4^–/–-eGFP mice. (C) Ratio of high GFP (Z+) and low GFP (Z–) expressing PCs in WT-eGFP (n = 35), ET4^–/–-eGFP (n = 33) and GLAST^–/–-eGFP (n = 16) mice that fire tonically, burst fire or are silent. (D) Coefficient of variation of ISI for WT-eGFP and ET4^–/–-eGFP PCs. Dotted line depicts CV = 1. (E) Spontaneous firing frequency of high GFP (Z+) and low GFP (Z–) expressing PCs in WT-eGFP, ET4^–/–-eGFP and GLAST^–/–-eGFP mice. Mean ± SEM.