A histochemical study of glutamate receptor in rat brain using biotinyl spider toxin.

Joro spider toxin (JSTX), a specific blocker of glutamate receptors, was conjugated with biotin. Using the avidin-biotin complex method, specific binding sites of biotinylated JSTX were demonstrated in the cerebellum and hippocampus of the rat. In the cerebellum, strong binding of biotinyl JSTX was observed on perikarya and dendrites of the Purkinje cells with much less binding in the granular cell layer. In the hippocampus, a dense staining was observed in the pyramidal cell layer, with more heavy binding in CA3 than in other sectors of Ammon's horn. The area of distribution of biotinyl JSTX binding sites corresponded well with that of receptors preferentially activated by quisqualate.