Spider toxin (JSTX) blocks glutamate synapse in hippocampal pyramidal neurons

Effects of spider toxin (JSTX)--a specific blocker of glutamate receptors--on single pyramidal neurons of the hippocampus were studied using tissue slices in vitro. JSTX blocked the synaptic response in CA1 pyramidal cells evoked by Schaffer collateral stimulation without affecting the antidromic spike potential. The toxin suppressed glutamate-induced cell firings whereas it had little effect on aspartate-induced responses. The results suggest that glutamate is a neurotransmitter of the Schaffer collateral input to CA1 pyramidal neurons.