[Expression of glial cells line-derived neurotrophic factor in the central nervous system of rat]

Glial cell line-derived neurotrophic factor (GDNF) iss a distant member of the transforming growth factor-beta, originally isolated by virtue of its ability to induce dopamine uptake and cell survival in cultures of embryonic ventral midbrain dopaminergic neurons, and more recently it has been shown to be a potent neurotrophic factor for motor neurons. However, the distribution of this molecule in the central nervous system (CNS) is not known yet. In the present study, the expression of GDNF of rat was investigated by using immunohistochemistry. GDNF immunoreactive fibers or bodies were found in molecular layer and Purkinje layer of cerebellum. In the spinal cord, neuronal expression was found widely, especially in ventral horn, Clarke's column. GDNF was also expressed in fiber terminals of I and II lamella of dorsal horn. Additionally, GDNA expression was found in the ependymal epithelium and neuroglia of spinal cord. The nuclei of neuroglia were stronger than perikaryon. The neurons in cerebral cortex showed very weak immunoreaction. We conclude that GDNF is expressed in many different cellular systems within the CNS, suggesting the multiple functions of GDNF in the adult CNS.