Fig. 8
Ca2+ influx through T-type is critical to induce Hebbian LTP at MPP-GCs. For comparison, the LTP time courses and LTP magnitudes of RS and BS in Fig. 7G are merged and shown as a control LTP time course and magnitude (gray). A Left, Representative voltage response to HFSH of MPP in the presence of APV (brown, 50 μM). Middle, Time course of normalized EPSP before and after HFSH. Right, Magnitudes of early (LTP5, open triangle) and late phase (LTP30, closed triangle) of LTP, indicating specific reduction of the early phase LTP by APV (Control, n = 12; APV, n = 6). B Similar as in A, but in the presence of nimodipine (Nimo, purple, 10 μM). Nimodipine had no significant effect on both early and late LTPAP. (Control: n = 12; Nimo: n = 6). C Left, Representative voltage response to HFSH of MPP in the presence of NiCl2 (green, 50 μM). Right, Mean Finit in the presence of NiCl2 (NiCl2: 67.0 ± 14.4 Hz, n = 5). Black dashed line denotes the mean value for Finit of both GC types (117.6 Hz, n = 15). D Similar as in A, but in the presence of NiCl2 (green). Late phase of LTP was significantly inhibited. E Similar as in D, but a pairing protocol was applied of HFSH. Both early and late LTP is significantly reduced. Shades and error bars, S.E.M. *p < 0.05. **p < 0.01. n.s., not significant (p > 0.05)