Localization of voltage-sensitive L-type calcium channels in the chicken retina

L-type calcium channels have been associated with synaptic transmission in the retina, and are a potential site for modulation of the release of neuro transmitters. The present study documents the immunohistochemical localizat ion of neuronal alpha1 subunits of L-type calcium channels in chicken retin a, using antibodies to the alpha 1c, alpha 1d and alpha 1f subunits of L-ty pe calcium channels. The alpha 1c-like subunits were localized to Muller ce lls, with predominantly radial processes, and a prominent band of horizonta l processes in the outer plexiform layer. The antibody to alpha 1d subunits labelled most, if not all, cell bodies. The antibody to a human alpha 1f s ubunit strongly labelled photoreceptor terminals. Fainter immunoreactivity was detected in the inner segments of the photoreceptors, a subset of amacr ine cells, two bands of labelling in the inner plexiform layer and many gan glion cells. The differential cellular distributions of these alpha1-subuni ts suggests subtle functional differences in their roles at different cellu lar locations.