Voltage gated CALCIUM CHANNEL SUBUNIT COMPOSITION AND DISTRIBUTION IN THE RETINA

Abstract

Abstract: : Purpose:To better understand the role of voltage gated calcium channels (VGCCs) in the retina. Methods:We used immunohistochemistry to identify the distribution of VGCC ß subunits in the retina of normal mice. To verify the specificity of each antibody and examine subunit redistribution, we used 4 mutant mouse lines that each lack a ß subunit (1–4). Results:We found the ß₂ to be localized to the outer plexiform layer (OPL); the ß₃ subunit was localized to three narrow and distinct bands within the inner plexiform layer (IPL); the ß₄ subunit was localized to three diffuse bands within the IPL. Loss of one ß subunit did not affect the distribution of other ß subunits. However, the loss of ß₂ subunit resulted in abnormal α_1F distribution in the OPL. Conclusions: The VGCCs critical for retinal signal transmission utilize the ß₂ and α_1F subunits in the OPL and mostly likely the ß₃ and ß₄ subunits in the IPL. Within the OPL the α_1F subunit pairs predominantly with the ß₂ subunit while within the IPL it may pair with either the ß₃ or ₄ subunit.

Keywords: anatomy • immunohistochemistry • ion channels