An intraocular injection of kainate induces expression of c-fos-like protein and activation of protein kinase C (alpha) in specific rabbit retinal neurones.

Intraocular injection of kainate into the rabbit eye causes both a translocation and transport of the bipolar cell's alpha PKC 6 h later. Although this effect is similar to what occurs for the phorbol ester, phorbol 12,13-dibutyrate (PDbut), it shows specificity in that N-methyl-D-aspartate (NMDA), 5,7-dihydroxytryptamine and 2-amino-4-phosphonobutyrate (APB) are ineffective. However, preliminary experiments suggest that, when injected into the eye, quisqualate also influences the alpha PKC of the bipolar cells. Injection of kainate into the rabbit eye shows that c-fos-like protein is expressed in certain amacrine and ganglion but not in bipolar cells 6 h later. This expression of c-fos immunoreactivity is transient because 15 h after the injection of kainate no positive staining was seen. It was not possible to analyse the kainate-induced c-fos expression for periods of less than 6 h because the anaesthetic used, Hypnorm, induced c-fos-like protein expression which lasted for 2-4 h.