Ciliary neurotrophic factor prevents retrograde neuronal death in the adult central nervous system.

The neurocytokine ciliary neurotrophic factor (CNTF) was described originally as an activity that supports the survival of neurons of the chicken ciliary ganglia in vitro. The widespread expression of CNTF and its principal binding protein, CNTF receptor alpha, in the central and peripheral nervous systems suggests a broader trophic role for this peptide. In the present study, we report that CNTF prevents axotomy-induced cell death of neurons in the anteroventral and anterodorsal thalamic nuclei of the adult rat. Using the polymerase chain reaction, we also demonstrate the presence of CNTF and CNTF receptor alpha mRNA in these same thalamic nuclei. The coincidence of CNTF and its receptor in a population of neurons responding to the factor suggests a paracrine function for CNTF. The present findings establish that CNTF has significant effects on neurons of the central nervous system in vivo and demonstrate that neurocytokines can prevent cell death in the adult central nervous system.