D2 modulation of GABAergic synaptic plasticity. (a and g) show representative IPSC traces before (top) and after HFS (middle) in the presence of the D2 agonist (Quinelorane, 10 μM) and the D2 antagonist (sulpiride, 1 μM), respectively, and an overlap of the recordings (bottom). (b, h, and m) are the time course of the IPSC amplitude before and after HFS in the presence of Quinelorane or sulpiride. (c and i) illustrate the distribution, in percentages, of the types of plasticity that were generated in the presence of the D2 agents. (d and j) are the PPR comparison of the IPSCs before and after HFS in presence of Quinelorane or sulpiride. (e and k) are the rise time and (f and l) are the decay time in the presence of Quinelorane or sulpiride before and after HFS. (n) HFS in the presence of sulpiride blocks the generation of LTD.