Concentration jump studies of intracellularly dialysed Xenopus oocytes show desensitization of kainate receptors.

The techniques of intracellular dialysis and 'concentration jump' have been applied to Xenopus oocytes injected with rat brain RNA. Changes in the internal ionic environment of the oocyte through intracellular perfusion via patch pipettes, in whole cell recording mode, led to expected changes in the reversal potential for current induced during application of L-kainic acid. The responses to this amino acid were also studied using the agonist 'concentration jump' technique. Dose-response relationships for L-kainate were similar to those obtained with oocyte superfusion, but the L-kainate-induced currents exhibited desensitization.