Tyrosine hydroxylase-positive fibers and neurons in transplanted striatal tissue in rats with quinolinic acid lesions of the striatum

Using the quinolinic acid (QA) animal model of Huntington's disease (HD) the dopaminergic afferent input to intrastriatal striatal grafts was examined. After bilateral striatal lesions with QA (15 nmol), 4 microliters of fetal (E17) striatal tissue were delivered into the lesioned striata. Twenty-eight weeks posttransplantation the tissue was processed for TH immunocytochemistry and cresyl violet staining. In addition fetal intact brains (E17) were also processed for TH immunocytochemistry and cresyl violet staining. Viable striatal grafts were located within the host striatum and in some cases within the lateral ventricles. TH-positive fibers were present within the graft and also groups of TH-positive cell bodies were seen in some of the grafts. TH immunocytochemistry on E17 fetuses revealed several groups of TH-positive neurons one of which was placed immediately ventral to the developing striatal ridge. The origin of TH-positive innervation within the graft is discussed.