Localization of Rod Bipolar Cells in the Mammalian Retina Using an Antibody Against the [alpha]1c L-type Ca2+ Channel

• Published in: Acta histochemica et cytochemica 2015-03, Vol.48 (2), p.47
• Main Authors: Huh, Yu-Jin, Choi, Jae-Sik, Jeon, Chang-Jin
• Format: Article
• Language: English
• ISSN: 0044-5991; 1347-5800

Bipolar cells transmit stimuli via graded changes in membrane potential and neurotransmitter release is modulated by Ca2+ influx through L-type Ca2+ channels. The purpose of this study was to determine whether the [alpha]1c subunit of L-type voltage-gated Ca2+ channel ([alpha]1c L-type Ca2+ channel) colocalizes with protein kinase C alpha (PKC-[alpha]), which labels rod bipolar cells. Retinal whole mounts and vertical sections from mouse, hamster, rabbit, and dog were immunolabeled with antibodies against PKC-[alpha] and [alpha]1c L-type Ca2+ channel, using fluorescein isothiocyanate (FITC) and Cy5 as visualizing agents. PKC-[alpha]-immunoreactive cells were morphologically identical to rod bipolar cells as previously reported. Their cell bodies were located within the inner nuclear layer, dendritic processes branched into the outer plexiform layer, and axons extended into the inner plexiform layer. Immunostaining showed that [alpha]1c L-type Ca2+ channel colocalized with PKC-[alpha] in rod bipolar cells. The identical expression of PKC-[alpha] and [alpha]1c L-type Ca2+ channel indicates that the [alpha]1c L-type Ca2+ channel has a specific role in rod bipolar cells, and the antibody against the [alpha]1c L-type Ca2+ channel may be a useful marker for studying the distribution of rod bipolar cells in mouse, hamster, rabbit, and dog retinas.