FIGURE 5.

Thioperamide (10 μM), an H₃ receptor antagonist, blocks RAMH-induced suppression of uIPSCs in FS/non-FS→Pyr connections. (A) A scheme of a FS→Pyr connection with suprathreshold voltage responses of FS and Pyr cells in response to depolarizing current pulse injection. (B) uIPSC recordings from the pyramidal cell in response to an injection of five short train pulses to the FS (2 ms, +80 mV, 20 Hz; upper traces) shown in (A) (Vh = –70 mV). Eleven consecutive traces (gray) and their average traces (black) are shown. RAMH (10 μM) had little effect on the uIPSC amplitude under application of thioperamide. Note that a slight increase of the uIPSC amplitude was induced through the application of thioperamide alone. (C) Time course of the uIPSC amplitude and IR. The periods of thioperamide and RAMH application are shown on the top of the graph. (D) The slight effect of RAMH on the uIPSC amplitude under application of thioperamide (n = 14). (E) The effects of thioperamide on the uEPSC (n = 5). (F) The effects of thioperamide on the uIPSC amplitude (n = 10). Note the significant increase in uIPSC amplitude after thioperamide application without changes in the failure rate and paired-pulse ratio of uIPSCs. (G) The normalized amplitude of the 1st to 5th uIPSCs (n = 10). Filled and open circles indicate the normalized amplitude of uIPSCs in control and during thioperamide application, respectively. ^∗P < 0.05, ^∗∗P < 0.01, paired t-test.