Developmental regulation of nerve growth factor and its receptor in the rat caudate-putamen.

In prior studies, nerve growth factor (NGF) administration induced a robust, selective increase in the neurochemical differentiation of caudate-putamen cholinergic neurons. In this study, expression of NGF and its receptor was examined to determine whether endogenous NGF might serve as a neurotrophic factor for these neurons. The temporal pattern of NGF gene expression and the levels of NGF mRNA and protein were distinct from those found in other brain regions. NGF and high-affinity NGF binding were present during cholinergic neurochemical differentiation and persisted into adult-hood. An increase in NGF binding during the third postnatal week was correlated with increasing choline acetyltransferase activity. The data are consistent with a role for endogenous NGF in the development and, possibly, the maintenance of caudate-putamen cholinergic neurons.