Electrophysiological evidence for tectal efferents to the neurons projecting to the retina in a teleost fish.

Neurons projecting to the retina were identified electrophysiologically by antidromic responses in the preoptic retinopetal nucleus (PRN), which is the major origin of the centrifugal fibers to the retina in the filefish. Electrical stimulation of the optic tectum demonstrated that such neurons received excitatory inputs directly from the optic tectum.