MK-801 is cytotoxic to microglia in vitro and its cytotoxicity is attenuated by glutamate, other excitotoxic agents and atropine. Possible presence of glutamate receptor and muscarinic receptor on microglia.

We examined the cytotoxicity of MK-801 on cultured microglia and demonstrated its cytotoxicity. Cytotoxicity of MK-801 was reduced by the addition of L-glutamate, kainate and NMDA. The action of MK-801 was due to the direct action of microglia. It suggested the existence of glutamate receptor in microglia. Cytotoxicity of MK-801 was reduced by the addition of atropine sulfate which suggested the presence of muscarinic receptor in microglia.