Referenced in: none

Automatically associated channels: Kir6.2

Title: Ablation of P/Q-type Ca(2+) channel currents, altered synaptic transmission, and progressive ataxia in mice lacking the alpha(1A)-subunit.

Authors: K Jun, E S Piedras-Rentería, S M Smith, D B Wheeler, S B Lee, T G Lee, H Chin, M E Adams, R H Scheller, R W Tsien, H S Shin

Journal, date & volume: Proc. Natl. Acad. Sci. U.S.A., 1999 Dec 21 , 96, 15245-50

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/10611370

Abstract
The Ca(2+) channel alpha(1A)-subunit is a voltage-gated, pore-forming membrane protein positioned at the intersection of two important lines of research: one exploring the diversity of Ca(2+) channels and their physiological roles, and the other pursuing mechanisms of ataxia, dystonia, epilepsy, and migraine. alpha(1A)-Subunits are thought to support both P- and Q-type Ca(2+) channel currents, but the most direct test, a null mutant, has not been described, nor is it known which changes in neurotransmission might arise from elimination of the predominant Ca(2+) delivery system at excitatory nerve terminals. We generated alpha(1A)-deficient mice (alpha(1A)(-/-)) and found that they developed a rapidly progressive neurological deficit with specific characteristics of ataxia and dystonia before dying approximately 3-4 weeks after birth. P-type currents in Purkinje neurons and P- and Q-type currents in cerebellar granule cells were eliminated completely whereas other Ca(2+) channel types, including those involved in triggering transmitter release, also underwent concomitant changes in density. Synaptic transmission in alpha(1A)(-/-) hippocampal slices persisted despite the lack of P/Q-type channels but showed enhanced reliance on N-type and R-type Ca(2+) entry. The alpha(1A)(-/-) mice provide a starting point for unraveling neuropathological mechanisms of human diseases generated by mutations in alpha(1A).