Figure 3.

Blockade of kainate receptors reversibly reduces disinhibition. (A) Effect of kynurenic acid (2.5 mM) in one cell. Upper, superimposed averages of conditioned (thick lines) and unconditioned PSCs (thin lines) recorded before (1), during (2), and after (3) perfusion with kynurenic acid. Lower, proximal PSC amplitude plotted against time. The averaged traces were obtained at the times indicated (numbers in brackets indicate % decrease in PSC amplitude produced by the conditioning train). The depression of inhibition was abolished by kynurenic acid and partially recovered following washout. (B) Effect of gadolinium studied in another cell. The averaged PSCs were obtained before (1), during (2), and after (3) perfusion with 10 μM Gd³⁺. (C) Averaged results obtained in 11 cells (washout data was obtained in 8 cells). Each point shows the average of three successive trials. The depression of the PSC by the conditioning train disappeared in the presence of Gd³⁺ and recovered after washout. APV and GYKI52466 were present throughout all of the illustrated experiments.