Journal of Neuroscience Research 4k663-676 (1995) Neurons Express Ciliary Neurotrophic Factor mRNA in the Early Postnatal and Adult Rat Brain

The regional and subcellular localization in the cen-tral nervous system (CNS) of postnatal day 5, day 15, and adult rats of ciliary neurotrophic factor (CNTF) mRNA was examined by in situ hybridization with biotinylated riboprobes. Probe specificity was deter-mined by Northern blot analysis of poly(A)+ RNA extracted from adult rat brain using digoxigenin la-beled riboprobes and chemiluminescent detection. Both a 4 kb and a 1.2 kb transcript were detected in the cortex and brainstem. In situ hybridization re-vealed that CNTF mRNA was widely distributed in neurons and glia throughout the CNS at each of the developmental time points. The density of the neu-ronal hybridization signal was found to be greater in neuronal nuclei than in their cytoplasm. In the nu-cleus of most neurons, CNTF mRNA distribution was concentrated in a perinucleolar fashion. Alternate sections from the same animals, which were incu-bated with a specific polyclonal antibody against a CNTF peptide fragment, revealed that both neurons and glia in postnatal day 5, day 15, and adult rat brain were immunoreactive for CNTF