EN
Noninvasive current stimulation is a rapidly developing tool for rehabilitation of visual impairment. The therapeutic use of current stimulation requires solving many technical problems including optimal placement of stimulating electrodes (SE). In this study we asked the question about origin of electrically evoked potential (EEP) and it’s dependence on the placement of the SE. In acute experiments on rats under urethane anaesthesia, visually (VEP) and electrically evoked potentials were recorded using single- and multi-channel electrodes from 5 visual structures: retina (1 channel), lateral geniculate nucleus (8 channels), superior colliculus (7 channels) and visual cortex of both hemispheres (16 channels each). Recordings of EEPs were performed to electrical pulse current stimulation, delivered using two electrodes placed either on one eye-ball (eye-eye montage) or on the eye-ball and neck (eyeneck montage). To reveal the origin of EEPs in both electrode montages 5 µl of tetrotodoxine (TTX 0.5 mM), was injected into the eye to block retinal ganglion cells’ activity and EEPs were recorded for both SE configurations. Lack of VEPs confirmed the successful block of ganglion cells’ activity. We have observed full decay of EEPs after TTX injection independent on the SE configurations. These results indicate on the retinal origin of EEPs regardless of the reference electrode placement. Supported by ERA-NET Neuron project REVIS.