Figure 1: Corticostriatal STDP occurs within a restricted time window.
From: Astrocytes gate Hebbian synaptic plasticity in the striatum
(a) Scheme of the recording and stimulating sites in corticostriatal slices. (b) STDP pairings: a single spike evoked in the recorded striatal MSN was paired with a single cortical stimulation; this pairing being repeated 100 times at 1 Hz. ΔtSTDP indicates the time between pre- and postsynaptic stimulations. ΔtSTDP<0 and ΔtSTDP>0 refer to post–pre and pre–post pairings, respectively. (c) Example of LTP induced by 100 post–pre pairings (ΔtSTDP=−12 ms). Top, EPSC strength before and after pairings. Bottom, time course of Ri (baseline: 67±0.3 MΩ and 50–60 min after pairings: 79±0.8 MΩ; change of 18%). EPSC traces during 10 min of baseline (1) and at 1h after the STDP protocol (arrow) (2). (d) Example of LTD induced by 100 pre–post pairings (ΔtSTDP=+13 ms; Ri, baseline: 106±0.5 MΩ; 50–60 min after pairings: 116±0.5 MΩ; change of 9%). (e) Averaged time-course of LTP induced by 100 post–pre pairings and LTD induced by 100 pre–post pairings. (f) Bidirectional STDP occurred in a narrow time window: post–pre pairings (−30<ΔtSTDP<0 ms) induced LTP, whereas pre–post pairings (0<ΔtSTDP<+30 ms) induced LTD. Synaptic strength was determined 45–60 min after pairings (empty circles: individual neurons; black circle: average). The y axis is discontinuous for clarity; plasticity amplitudes above the interruption are 312 pA, 367 pA and 424 pA. (g) Uncorrelated post–pre (−250<ΔtSTDP<−100) and pre–post (+100<ΔtSTDP<+250 ms) pairings induced no significant plasticity. (h) Post–pre or pre–post pairings with ΔtSTDP∼±500 ms induced no significant plasticity. (i) Graph summarizing STDP occurrence. Bidirectional plasticity was induced over a narrow time window (−30<ΔtSTDP<+30 ms), whereas no plasticity was observed with uncorrelated pairings (−500<ΔtSTDP<−30 ms and +30<ΔtSTDP<+500 ms). Insets correspond to a mean of 60 EPSCs during baseline and at 1 h after STDP pairings. Error bars represent the s.d. (except in f,i: s.e.m.). *P<0.05; ***P<0.001; NS: not significant by unpaired t-test, two-tailed (c,d) or one sample t-test (e–i).
