Synaptic 25 Hz trains do not engage group I mGluRs in dSPNs. A, Grouped data of normalized amplitudes of EPSCs E1–E5 during 25 Hz trains in the presence of MPEP in dSPNs from WT and D1cre;Grik2 f/f mice. B, E5/E1 ratio in dSPNs from control mice and D1cre;Grik2 f/f mice. C, Representative E1 and E5 traces from individual experiments in control and conditional GluK2 KO mice in the presence of MPEP. Calibration: 200 pA (top), 400 pA (bottom), 10 ms.