Figure 7.

Effect of GrC-GoC synaptic weight on GrC activity. In these simulations the following weight configuration was used: MF-GrC 0.61 nS (LTD), 0.87 nS (control), or 1.13 nS (LTP) (AMPA-receptor weights), MF-GoC 1 nS, GrC-GoC 3 nS, GoC-GrC 1.5 nS, SC-GoC 0 nS, GoC-GoC 0 nS. (A) GrC response with MF-GrC control configuration and three different GrC-GoC weights: LTD (1.5 nS, green), Control (3 nS, red), and LTP (6 nS, blue). The theoretical distribution of the MF stimulation burst is shown with a dashed line. (Top) Membrane potential in a single GrC and its firing threshold (dotted straight line at −40 mV). (Middle) E/I g balance of the GrC population. (Bottom) PSTH of the GrC response after the first spike in the burst. GrC-GoC did not influence the GrC response during the initial part of the burst in MF-GrC control conditions. (B) Average input/output offset (top) and GrC firing probability (bottom) with respect to GrC-GoC weights. The changes observed in conjunction with three different MF-GrC weights (LTD dot dash line; control solid line; LTP dashed line) are shown for comparison. Note that the effect of GrC-GoC becomes patent only in conjunction with medium/high MF-GrC weights (control and especially LTP). (C) Relative number of GrCs generating zero, one, two, or three spikes in response to the stimulation burst. These are reported for three different MF-GrC configurations.