NEURONS EXPRESS CILIARY NEUROTROPHIC FACTOR MESSENGER-RNA IN THE EARLY POSTNATAL AND ADULT-RAT BRAIN

The regional and subcellular localization in the central nervous syste m (CNS) of postnatal day 5, day 15, and adult rats of ciliary neurotro phic factor (CNTF) mRNA was examined by in situ hybridization with bio tinylated riboprobes. Probe specificity was determined by Northern blo t analysis of poly(A) + RNA extracted from adult rat brain using digox igenin labeled riboprobes and chemiluminescent detection. Both a 4 kb and a 1.2 kb transcript were detected in the cortex and brainstem, In situ hybridization revealed that CNTF mRNA was widely distributed in n eurons and glia throughout the CNS at each of the developmental time p oints, The density of the neuronal hybridization signal was found to b e greater in neuronal nuclei than in their cytoplasm, In the nucleus o f most neurons, CNTF mRNA distribution was concentrated in a perinucle olar fashion. Alternate sections from the same animals, which were inc ubated with a specific polyclonal antibody against a CNTF peptide frag ment, revealed that both neurons and glia in postnatal day 5, day 15, and adult rat brain were immunoreactive for CNTF. (C) 1995 Wiley-Liss, Inc.