Recording of Electroretinogram and Visual Evoked Potential in a Rat

Begin with a rat with surgically implanted electrodes in its eye and brain.

The electroretinogram, or ERG electrode, measures the electrical activity of the retina, while the visual evoked potential, or VEP electrodes, record brain signals.

These electrodes are connected to a transmitter implanted in the rat's abdomen.

Dark-adapt the animal before the recordings.

Perform the procedure under dim red light.

Apply anesthetic and dilating drops to the cornea.

Guide the animal into a restrainer to minimize head movement.

Position the animal in front of the Ganzfeld bowl, which ensures uniform exposure of the retina under controlled illumination.

Align the animal's eyes with the opening of the bowl.

Pass a magnet over the implanted transmitter to turn it on. Confirm its activation on the receiver.

Record ERG and VEP signals under different illumination conditions.