Visual cortical potentials of the mouse evoked by electrical stimulation of the retina.

An electrical evoked potential (EEP) of the visual system is a summed electrical record of the visual cortex in response to electrical stimulation of the retina. It is the primary method in the assessment of a visual prosthesis which targets at restoring vision to individuals with disease of the outer retina. However despite marked enthusiasm in the fabrication of such devices, little is known about the feasibility of such devices with the visually deprived brain. Recent research in visual plasticity has demonstrated that the adult brain retains marked plasticity following visual deafferentation. The deprived visual cortex may be recruited to process other sensory modality in a cross-modal manner, thus vitiating its capacity to process restored visual input. In this regard, the mouse benefited with a wealth of mutant models and transgenic technology may help to unravel many of the underlying mechanisms of neuroplasticity and provide novel avenues to manipulate such changes. Nevertheless, the feasibility of recording EEP in the mouse has not been established to date. In this study we successfully established a noninvasive technique for stimulation and recording mouse EEP. The approach provides a tool for not only investigating the plastic changes in visual processing following deafferentation but also longitudinal and live data collection for in vivo evaluation of a prosthetic device.