抄録
[Purpose] We previously reported that electrical stimulation (ES) to the sectioned optic nerve (ON) enhances the survival of adult cat retinal ganglion cells (RGCs) a week after axotomy. This effect was, however, limited to the RGCs on the area centralis (AC). Here we report the optimal current intensity and the effect of ES on each RGC type. [Methods] RGCs were labeled retrogradely with DiI in advance. Immediately after left ON transection, ES of 20 Hz square pulses with 300 μsec duration was applied for 2 hours via a cuff electrode attached to the ON stump. The current intensity was varied at 0.5, 1.0, 3.0 or 5.0 mA. After a week survival, the survival rate of total RGCs was calculated as the ratio of total number of surviving RGCs in the transected retina to that in the paired intact one. To examine the survival rate of each RGC type, each RGC was classified into alpha, beta or other cell by intracellular injection of Lucifer yellow. [Results] The 3.0 mA ES improved the survival rate of the total RGCs as well as that of RGCs in the AC, whereas 1.0 mA ES did only in the AC. The 5 mA ES did not improve the survival rate. The ES of 3.0 mA promoted the survival of beta cells, but not that of alpha cells. [Conclusion] The current intensity of 3 mA is optimal to promote the survival of axotomized adult cat RGCs. This ES is effective to beta cells that are important to the central vision. [Jpn J Physiol 54 Suppl:S164 (2004)]
