Locomotor hyperactivity: effects of multiple striatal transplants in an animal model of Huntington's disease.

Huntington's disease is characterized by gross degeneration of the intrinsic neurons of the striatum, restless hyperkinetic choreiform movements and dementia. Rats which received injections of kainic acid have provided an extremely viable model for this extrapyramidal movement disorder. The present preliminary report investigated the effects of multiple homotopic transplantations of normal fetal Day 17 striatal ridge tissue into the lesioned striatum of male kainic acid-treated rats. Nine weeks after transplantation, the spontaneous nocturnal hyperkinetic locomotor abnormalities as measured by horizontal activity and total distance travelled were attenuated in the striatal transplanted animals compared to sciatic nerve transplanted controls. Similarly, the exacerbated response to d-amphetamine exhibited by the animal model was attenuated in the striatal transplanted animals. The striatal transplants reconstructed much of the gross morphology of the lesioned striatum, although acetylcholinesterase was found to be reduced.