Long-term enhancement of K⁺-evoked release of l-glutamate in entorhinal kindled rats

Kainic acid- and K⁺-evoked in vitro release of endogenous amino acids from hippocampal slices were measured in rats kindled by entorhinal electrical stimulation. One month after completion of kindling, K⁺-evoked release of glutamate from hippocampal slices ipsilateral to the stimulus site was consistently greater than from both the contralateral hippocampus from kindled animals and all hippocampi of electroshock and sham-surgery control groups. Enhanced hippocampal neurotransmitter glutamate release may be involved in the permanent effects of electrical kindling.