Kainic acid: neurophysiological and neurotoxic actions.

Kainic acid, an anthelmintic drug structurally related to glutamate, has excitatory electrophysiological actions on neurons in the vertebrate CNS and at the invertebrate neuromuscular junction. Recently, it has been shown to destroy neuronal cell bodies and dendrites in several regions of the vertebrate CNS, while sparing afferent fibers and fibers of passage. Kainic acid can be used to make lesions in experimental animals that closely resemble the pathology associated with certain neurological conditions in man. Its actions on vertebrate and invertebrate nervous systems are reviewed and possible neuroexcitatory and neurotoxic mechanisms are considered.