Visual deficits following intraocular treatment of chicks with glutamate or kainic acid

After intraocular treatment with kainate or glutamate, chicks were tested for visual discrimination performance, pecking aim, bead detection, optokinetic response and pupillary response. Kainate at an amount of 6 nmol per eye impaired performance in all of the tests except pupillary response. No effects were seen after 0.6 nmol of kainic acid. Glutamate at 6000 nmol impaired performance on all tests but the optokinetic and pupillary response. Although glutamate caused less severe deficits in visual behaviour than the high dose of kainate, cellular organization of the retina, at least in some regions, was more disrupted in these animals. Glutamate at 600 nmol caused a late onset defect in visual discrimination performance but no effects on optokinetic response.