A, a representative experiment examining the effect of DHPG (horizontal bar) in the presence of nifedipine (an L-VDCC blocker; dotted horizontal bar). B, averaged calcium currents recorded at the times indicated by a–c in A. The trace b is superimposed (a grey trace) on the traces a and c. Calibration: 10 pA, 100 ms. C, the DHPG-induced calcium-current facilitation in the presence (filled circles; n= 9) and the absence (open circles; n= 9) of nifedipine. D, coimmunoprecipitation of mGluR5 with Cav1.2, Homer and mGluR5.