Direct stimulation of optic nerve by electrodes implanted in optic disc of rabbit eyes

Xiaoyun Fang, Hirokazu Sakaguchi, Takashi Fujikado, Makoto Osanai, Hiroyuki Kanda, Yasushi Ikuno, Motohiro Kamei, Masahito Ohji, Dekang Gan, Junsub Choi, Tetsuya Yagi, Yasuo Tano

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)


Purpose: To determine whether wire microelectrodes implanted in the optic disc can be used to elicit cortical potentials. Methods: Two or four platinum wire electrodes of two types, viz., the cut-end type and the exposed-tip type, were inserted through the vitreous and fixed in the optic disc of 16 rabbit eyes. Electrically evoked potentials (EEPs) were recorded after bipolar electrical stimulation with the two wire electrodes and by different combinations of the four-electrode system. The optic discs were examined histologically after the experiment. Results: The wire electrodes were successfully implanted and fixed into different positions of the optic disc without serious complications in all 16 eyes. EEPs could be elicited after bipolar electrical stimulation of the optic nerve using either the two-electrode system or different pairs of the four-electrode system. Threshold charge densities to elicit EEPs were 0.32-0.64 mC/cm2 in eyes using the cut-end type of electrodes and 0.93-6.21 μC/cm2 in eyes using the exposed-tip type. The amplitude of the EEPs increased with increasing electrical stimulus intensities. Histological evaluation revealed limited damage to the neural tissue adjacent to the electrode track. Conclusions: The visual cortex can be activated by direct microelectrical stimulation of the optic nerve. The acute implantation of the wire microelectrodes into the optic disc by a transvitreal approach is feasible and results in only limited damage to the optic nerve.

Original languageEnglish
Pages (from-to)49-56
Number of pages8
JournalGraefe's Archive for Clinical and Experimental Ophthalmology
Issue number1
Publication statusPublished - 2005 Jan
Externally publishedYes

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience


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