Figure 6.

The D3 receptor agonist PD128907 alters both the frequency and the amplitude of spontaneous, tetrodotoxin-resistant inhibitory postsynaptic currents (IPSCs). Miniature IPSCs (mIPSCs) (a) were recorded in the presence of tetrodotoxin and high concentrations of intracellular chloride (see Materials and Methods). For an exemplar cell, PD128907 significantly shifted the cumulative probability distribution of mIPSC amplitude to the left (b₁; KS statistic=0.23, P<0.01) and the mIPSC interevent interval to the right (c₁; KS=0.18, P<0.05). Summary graphs across all cells (n=5) shows that PD128907 significantly inhibited both mIPSC amplitude (b₂; ^**P<0.01, paired t-test) and mIPSC frequency (c₂; ^*P<0.05, paired t-test).