Figure 2.

Phase shifts are blocked by NMDA and non-NMDA antagonists. A, Average biphasic (Biph.; top) and RD (bottom) responses triggered by glutamate (30 μm, 30 s, arrowhead) in the control condition (full line) or in the presence of the following antagonists (dotted line): DNQX (30 μm; A1); MK801 (40 μm; A2); and TTX (1 μm; A3). With DNQX, the blockade is complete. With MK801 or TTX, biphasic and RD responses are strongly decreased compared with control condition. However, a residual component with a biphasic shape persisted (i.e., biphasic-like). B, With a glycine (Glyc.; 10 μm) and Mg²⁺-free extracellular solution, the same application of glutamate (30 μm, 30 s, arrowhead) triggers a strong increase of phase signal like biphasic response (full line) or the RD response (dotted line), in the presence of DNQX (B1) or TTX (B3), but not in the presence of MK801 (B2). Calibration: 2 min and 5°.