Friday, May 9, 2025
5/9/2025
The role of P/Q-type channels in oligodendrocyte lineage cell development - Project Summary/Abstract Oligodendrocyte lineage cells (OLCs) are the myelin-producing cells in the central nervous system, which possess ion channels and are sensitive to neuronal activity. P/Q-type channels are voltage-gated calcium channels that are present in neurons and OLCs, and though their function in neurons has been studied, the role of these channels in OLCs is unknown. Mutations in CACNA1A, the human gene that encodes the main pore- forming subunit of P/Q-type channels, have been shown to cause neurological disorders including episodic ataxia, epilepsy, and intellectual disability in human patients. Studying the role of P/Q-type channels in OLCs will aid in understanding CACNA1A-related disorder pathophysiology and may uncover new targets for treatment. In this study, I will use zebrafish as a model to produce mutations in CACNA1A equivalent genes in OLCs during development, then use in vivo imaging with fluorescent transgenes to determine if myelin formation and calcium signaling is disrupted in OLCs with disrupted P/Q-type channels. My preliminary findings show P/Q-type channel mutations in OLCs cause reduced developmental myelination. To test how P/Q-type channels are involved in CACNA1A-related disorder pathology, I will generate a global mutant zebrafish to model CACNA1A-related disorders by using CRISPR/Cas9-mediated mutagenesis to produce mutations replicating those found in CACNA1A-related disorders. I will use fluorescent imaging to assess developmental myelination in this mutant, and I will use whole-brain calcium imaging and a motor assay to evaluate neural function relevant to ataxia seen in human disease. I will also generate a transgenic mutant zebrafish line with mutant P/Q-type channels in all cells and wild-type P/Q-type channels expressed specifically in OLCs to determine how OLC P/Q-type channels are involved in CACNA1A-related disorder pathology. To further understand the role of P/Q-type channels in OLC development, I will perform whole-cell voltage-clamp recordings in OLCs in the developing zebrafish spinal cord. By measuring currents in developing OLCs in wild-type and mutant zebrafish with and without ion channel agonists and antagonists, I will be able to directly measure changes in OLC electrophysiological properties due to P/Q-type channel mutations. These experiments will establish the new method of whole-cell patch-clamp recording from zebrafish spinal cord OLCs and lay the groundwork for many future studies. Together, this study will provide fundamental insights of ion channel function in OLCs as well as OLC involvement in CACNA1A- related disorders and provide future directions for understanding the role of OLCs in neurological disease.
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