Fig. 5.

Comparison of desensitization of AMPAR-mediated responses before and after ischemia. A, Examples of whole-cell currents induced by 1 mm AMPA at 4 hr after ischemia before and after application of CTZ. After treatment with 100 μm CTZ, the amplitude of glutamate-induced responses dramatically increased. B, Current density of AMPA-induced responses in LA neurons was approximately the same before and after ischemia. No difference in current density was found between control and ischemic neurons after application of CTZ, despite the current density values of all neurons that were significantly increased. C, Representative traces showing the decay of evoked EPSCs were well fitted by the single exponential method. The traces are the average of six consecutive recordings.D, Histogram showing that the mean decay time of EPSCs in LA neurons did not change after ischemia. The above results indicate that desensitization plays little role in synaptic depression of LA neurons after ischemia.