Type 1 ryanodine receptor knock-in mutation causing central core disease of skeletal muscle also displays a neuronal phenotype
Department of Microbiology and Physiological Systems; Biomedical Imaging Group
Life Sciences | Medicine and Health Sciences | Neuroscience and Neurobiology
The type 1 ryanodine receptor (RyR1) is expressed widely in the brain, with high levels in the cerebellum, hippocampus, and hypothalamus. We have shown that L-type Ca(2+) channels in terminals of hypothalamic magnocellular neurons are coupled to RyRs, as they are in skeletal muscle, allowing voltage-induced Ca(2+) release (VICaR) from internal Ca(2+) stores without Ca(2+) influx. Here we demonstrate that RyR1 plays a role in VICaR in nerve terminals. Furthermore, in heterozygotes from the Ryr1(I4895T/WT) (IT/+) mouse line, carrying a knock-in mutation corresponding to one that causes a severe form of human central core disease, VICaR is absent, demonstrating that type 1 RyR mediates VICaR and that these mice have a neuronal phenotype. The absence of VICaR was shown in two ways: first, depolarization in the absence of Ca(2+) influx elicited Ca(2+)syntillas (scintilla, spark, in a nerve terminal, a SYNaptic structure) in WT, but not in mutant terminals; second, in the presence of extracellular Ca(2+), IT/+ terminals showed a twofold decrease in global Ca(2+) transients, with no change in plasmalemmal Ca(2+) current. From these studies we draw two conclusions: (i) RyR1 plays a role in VICaR in hypothalamic nerve terminals; and (ii) a neuronal alteration accompanies the myopathy in IT/+ mice, and, possibly in humans carrying the corresponding RyR1 mutation.
DOI of Published Version
Proc Natl Acad Sci U S A. 2012 Jan 10;109(2):610-5. Epub 2011 Dec 27. Link to article on publisher's site
Proceedings of the National Academy of Sciences of the United States of America
De Crescenzo V, Fogarty KE, Lefkowitz JJ, Bellve KD, Zvaritch E, MacLennan DH, Walsh JV. (2012). Type 1 ryanodine receptor knock-in mutation causing central core disease of skeletal muscle also displays a neuronal phenotype. Morningside Graduate School of Biomedical Sciences Student Publications. https://doi.org/10.1073/pnas.1115111108. Retrieved from https://escholarship.umassmed.edu/gsbs_sp/1769