Retinal lesion by bright artificial light increases vasoactive intestinal polypeptide in the rat ventral tegmental...

Sprague-Dawley rats were treated with bright light to induce retinal lesions and vasoactive intestinal polypeptide in the ventral tegmental area/substantia nigra was measured by radioimmunoassay. In Sprague-Dawley rats, but not in Brown Norway rats where light did not induce retinal lesions, significantly increased concentrations of vasoactive intestinal polypeptide were found 21 days after exposure with bright light. This increase declined to control values 60 days after the treatment. Our studies indicate that vasoactive intestinal polypeptide may be involved in visual neurotransmission and that the ventral tegmental area/substantia nigra may be connected to retinal input.