Figure 1.
TC afferents evoke GluR2-lacking AMPAR-mediated EPSCs onto FS cells. A, Left, EPSCs evoked by TC stimulation and recorded in an RS and an FS cell voltage clamped at membrane potentials ranging from −76 to +44 mV, in gabazine (10 μm) and CPP (25 μm). Middle, Summary data of current–voltage relationships for TC-evoked EPSCs. Membrane potentials are corrected for liquid junction potential. Currents are normalized to the peak negative current, and 100 μm spermine is included in the patch pipettes. Right, Summary of rectification index (+34/−36 mV); filled square, RS cells; open square, FS cells. Only the FS cells show AMPAR-mediated current rectification. Asterisk denotes statistical significance. B, Left, EPSCs evoked by TC stimulation and recorded simultaneously in an RS and an FS cell voltage clamped at the reversal potential for IPSCs (EIPSC). Only the EPSC recorded in the FS cell is reduced in the presence of the GluR2-lacking AMPAR blocker NASPM (50 μm, green traces). Inset represents recording configuration. Abbreviations, here and in subsequent figures: VB, ventrobasal complex; Stim., stimulation electrode; V-clamp, voltage clamp. Right, Summary data illustrating the normalized EPSC amplitudes after application of NASPM; filled square, RS cells; open square, FS cells. C, NASPM (green) does not affect the rectification of TC EPSCs onto FS cells as compared to control (black). Left, Example traces. Middle, Summary data of current–voltage relationship. The RS cell data (gray, from A) are shown for comparison. Right, Summary of rectification index.