Up-regulated CNTF plays a protective role for retrograde degeneration in the axotomized rat retina.

Using reverse transcription-polymerase chain reaction and in situ hybridization, we investigated the expression and cellular localization of ciliary neurotrophic factor receptor alpha (CNTFRalpha) in the rat retina following optic nerve transection (ONT). Following ONT, a signal for CNTFRalpha mRNA appeared in a layer-specific and time-dependent manner. In the ganglion cell layer, the signal showed a peak value 1 day after ONT, and then gradually decreased. In the inner nuclear layer the signal reached a peak value at 14 days of about 500% of control level, but then decreased at 4 weeks. Our findings suggest that CNTF might play a protective role for the retrograde degeneration of retinal cells induced by ganglion cell death in the rat retina following ONT.