Reliability of Chronically Recorded Visually Evoked Potentials in Awake Mouse Visual Cortex: Effect of Restraint Habituation

Visual function in mice can be quantified using electrophysiological methods. This can be done using chronically implanted electrodes that record visually evoked potentials (VEPs) from a population of neurons in the primary visual cortex (V1) in order to estimate visual acuity. The inherently noisy environment of the brain presents a challenge, as the VEP signal is very small. Our goal is to optimize VEP recording procedures to produce the highest signal-to-noise ratio possible by investigating the role of restraint habituation. The approach we designed included three experimental groups: one in which the animals received regular stimulus exposure and no habituation, one in which the animals received 10 days of restraint habituation prior to 10 days of stimulus exposure, and one in which the animals received habituation only and no stimulus exposure. We found that restraint habituation is necessary in order to produce reliable VEPs. Furthermore, we discovered that over time there is an increase in VEP amplitude that is dependent upon visual experience. This experience-dependent effect is driven by repeated exposure to specific stimuli