Figure 5.

Corticostriatal STDP is modulated by dopamine D₂ receptor activation. A, Representative recording from an SPN. The STDP protocol that induced LTP in control conditions (Δt = 10 ms) also induced LTP in the presence of the D₂ dopamine receptor antagonist sulpiride (10 μm). B, Current–voltage relationship was unchanged before (red) and after (blue) the STDP protocol. Exemplary single traces were obtained in response to current injections ranging from −400 to 400 pA. C, Average of all recordings in the presence of sulpiride in which the STDP protocol with a delay of Δt = 10 ms between EPSP and AP was applied (n = 8). The onset of significant changes in EPSP size are indicated by brackets above traces (*p < 0.05). Gray line depicts control condition with no D₂ antagonist. D, Representative recording from an SPN. The STDP protocol that induced LTD in control conditions (Δt = −30 ms) also induced LTD in the presence of the D₂ dopamine receptor antagonist sulpiride (10 μm). E, Current–voltage relationships were unchanged before (red) and after (blue) the STDP protocol. Exemplary single traces were obtained in response to current injections ranging from −500 to 325 pA. F, Average of all recordings in the presence of sulpiride in which the STDP protocol with a delay of Δt = −30 ms between EPSP and AP was applied (n = 5). The onset of significant changes in EPSP size are indicated by brackets above traces (*p < 0.05). Gray line depicts control condition with no D₂ antagonist.