Changes in glutamic acid decarboxylase mRNA in the pallidum of the rat following unilateral damage of the striatum and overlying cortex.

The messenger RNA encoding glutamic acid decarboxylase (GAD) has been examined in the pallidum of the rat using in situ hybridization histochemistry following damage of the striatum and overlying frontal neocortex of one side. Following a postoperative survival time of 5 weeks, ipsilateral shrunken pallidal neurons showed significant decrease in GAD mRNA. The mRNA for GAD is significantly increased in neurons of the contralateral pallidum. These neurons are also significantly enlarged. These findings may be related to pathological changes in pallidal neurons in Huntington's disease.