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See also comment(s) by Makoto Aihara • Jeffrey Goldberg • Leonard A. Levin • Keith Martin • Barbara Lorber • Manuel Vidal-Sanz & James Morgan • Takuji Kurimoto •
PURPOSE: To investigate whether electrical stimulation promoted axonal regeneration of retinal ganglion cells (RGCs) after optic nerve (ON) crush in adult rats. METHODS: Transcorneal electrical stimulation (TES), which stimulates the retina with current from a corneal contact lens electrode, was used to stimulate the eye. TES was applied for 1 h immediately after ON crush. Axonal regeneration was determined by anterograde labeling of RGC axons. To examine whether the axonal regeneration was mediated by insulin-like growth factor 1 (IGF-1) receptors, an IGF-1 receptor antagonist, JB3, was injected intraperitoneally before each TES application. Immunostaining for IGF-1 was performed to examine the effects of TES. To test the survival-promoting effects of TES applied daily, the mean density of retrogradely labeled RGCs was determined on day 12 after ON crush. RESULTS: Compared with sham stimulation, the mean number of regenerating axons significantly increased at 250 microm distal from the lesion and increased IGF-1 immunoreactivity was observed in retinas treated daily with TES. Preinjection of an IGF-1 receptor antagonist significantly blocked axonal regeneration by TES applied daily. TES applied daily also markedly enhanced the survival of RGCs 12 days after ON crush. CONCLUSION: TES applied daily promotes both axonal regeneration and survival of RGCs after ON crush.
Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
11.8 Neuroprotection (Part of: 11 Medical treatment)