Upregulation of ciliary neurotrophic factor in reactive Muller cells in the rat retina following optic nerve transection

We have investigated the expression and cellular localization of ciliary neurotrophic factor (CNTF) in the rat retina following optic nerve transection. In the normal retina, CNTF immunoreactivity was restricted to profiles in the ganglion cell layer. Following optic nerve transection, immunoreactivity appeared in Muller cell somata and processes and its intensity increased between three and seven days post-lesion. Quantitative evaluation by immunoblotting confirmed that CNTF expression increased continuously up to 7 days after optic nerve transection (to 430% of control levels), but decreased again to 250% of controls at 4 weeks post-lesion. Our findings suggest that CNTF supplied by Muller cells may play a protective role for axotomized ganglion cells in the rat retina. (C) 2000 Elsevier Science B.V. All rights reserved.