CILIARY NEUROTROPHIC FACTOR-RECEPTOR ALPHA-IMMUNOREACTIVITY IN THE MONKEY CENTRAL-NERVOUS-SYSTEM

Ciliary neurotrophic factor (CNTF) sustains the viability and phenotyp ic expression of a variety of neuronal populations in the central nerv ous system. Cranial and spinal motor neurons are particularly sensitiv e to the trophic effects of CNTF, and clinical trials are underway tes ting the potential therapeutic value of this trophic factor in patient s with amyotrophic lateral sclerosis. Yet, the distribution of the alp ha subunit of the receptor for ciliary neurotrophic factor (CNTFR alph a), which is essential for the trophic effects of CNTF to occur, is un known in any primate species. Towards this end, the present study used a polyclonal antibody directed against CNTFR alpha to evaluate the di stribution of CNTFR alpha-immunoreactive (-ir) cells within the brain and spinal cord of Cebus apella monkeys. CNTFR alpha-ir was found excl usively within neurons. In the anterior horn of the spinal cord, virtu ally all motor neurons were darkly immunoreactive for CNTFR alpha. A s imilar pattern of CNTFR alpha-ir was seen within all cranial motor nuc lei with general somatic efferent function (III, IV, motor V, VI, VII, and XII cranial nerves). CNTFR alpha-ir was also seen in other region s involved with motor function including the Purkinje cells of the cer ebellum, the substantia nigra pars compacta, red nucleus, dorsal motor nucleus of X cranial nerve, and giant neurons of sensory motor neocor tex. A few CNTFR alpha-ir neurons were seen within the globus pallidus with concomitant terminal-like staining within the subthalamic nucleu s. Autonomic regions such as the mesencephalic nucleus of the trigemin al nerve and the interomedial lateral cell column of the thoracic spin al cord also contained CNTFR alpha-ir neurons. Finally, the hippocampu s displayed dense CNTFR alpha-ir within the pyramidal cell layer of th e hippocampal formation and the granule cell layer of the dentate gyru s. The dense expression of this CNTFR alpha protein within regions sub serving motor, autonomic, and sensory functions suggests that CNTFR al pha supports many central nervous system regions with diverse function s. J. Comp. Neurol. 377:365-380, 1997. (C) 1997 Wiley-Liss, Inc.