AN INTRAOCULAR INJECTION OF KAINATE INDUCES EXPRESSION OF C-FOS-LIKE PROTEIN AND ACTIVATION OF PROTEIN KINASE-C-(ALPHA) IN SPECIFIC RABBIT RETINAL NEURONS

Intraocular injection ot 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.