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.