Tissue and cell-type specific expression of a splice variant in the II-III cytoplasmic loop ofCacna1b

Abstract

ABSTRACTPresynaptic CaV2.2 (N-type) channels are fundamental for transmitter release across the nervous system. The gene encoding CaV2.2 channels,Cacna1b, contains alternatively spliced exons that originate functionally distinct splice variants (e18a, e24a, e31a and 37a/37b). Alternative splicing of the cassette exon 18a generates two mRNA transcripts (+e18a-Cacna1band Δe18a-Cacna1b). In this study, using novel mouse genetic models and in situ hybridization (BaseScope™), we confirmed that +e18a-Cacna1bsplice variants are expressed in monoaminergic regions of midbrain. We expanded these studies and identified +e18a-Cacna1bmRNA in deep cerebellar cells and spinal cord motor neurons. Furthermore, we determined that +e18a-Cacna1bis enriched in cholecystokinin expressing interneurons. Our results provide key information to understand cell-specific functions of CaV2.2 channels.