![]() |
|
|
Vol. 55, Issue 1, 23-31, January 1999
Department of Neuroscience and Anatomy, Pennsylvania State
University College of Medicine, Hershey, Pennsylvania
Tottering mice inherit a recessive mutation of the calcium channel
1A subunit that causes ataxia, polyspike discharges, and intermittent dystonic episodes. The calcium channel
1A
subunit gene encodes the pore-forming protein of P/Q-type
voltage-dependent calcium channels and is predominantly expressed in
cerebellar granule and Purkinje neurons with moderate expression in
hippocampus and inferior colliculus. Because calcium misregulation
likely underlies the tottering mouse phenotype, calcium channel
blockers were tested for their ability to block the motor episodes.
Pharmacologic agents that specifically block L-type
voltage-dependent calcium channels, but not P/Q-type calcium
channels, prevented the inducible dystonia of tottering mutant mice.
Specifically, the dihydropyridines nimodipine, nifedipine, and
nitrendipine, the benzothiazepine diltiazem, and the phenylalkylamine
verapamil all prevented restraint-induced tottering mouse motor
episodes. Conversely, the L-type calcium channel agonist
Bay K8644 induced stereotypic tottering mouse dystonic at
concentrations significantly below those required to induce seizures in
control mice. In situ hybridization demonstrated that
L-type calcium channel
1C subunit mRNA
expression was up-regulated in the Purkinje cells of tottering mice.
Radioligand binding with [3H]nitrendipine also revealed a
significant increase in the density of L-type calcium
channels in tottering mouse cerebellum. These data suggest that
although a P/Q-type calcium channel mutation is the primary defect in
tottering mice, L-type calcium channels may contribute to
the generation of the intermittent dystonia observed in these mice. The
susceptibility of L-type calcium channels to
voltage-dependent facilitation may promote this abnormal motor phenotype.
This article has been cited by other articles:
![]() |
N. E. Pardo, R. K. Hajela, and W. D. Atchison Acetylcholine Release at Neuromuscular Junctions of Adult Tottering Mice Is Controlled by N-(Cav2.2) and R-Type (Cav2.3) but Not L-Type (Cav1.2) Ca2+ Channels J. Pharmacol. Exp. Ther., December 1, 2006; 319(3): 1009 - 1020. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-N. Yang and P.-O. Berggren The Role of Voltage-Gated Calcium Channels in Pancreatic {beta}-Cell Physiology and Pathophysiology Endocr. Rev., October 1, 2006; 27(6): 621 - 676. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Imbrici, S. L. Jaffe, L. H. Eunson, N. P. Davies, C. Herd, R. Robertson, D. M. Kullmann, and M. G. Hanna Dysfunction of the brain calcium channel CaV2.1 in absence epilepsy and episodic ataxia Brain, December 1, 2004; 127(12): 2682 - 2692. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Zhang, A. P. Vilaythong, D. Yoshor, and J. L. Noebels Elevated Thalamic Low-Voltage-Activated Currents Precede the Onset of Absence Epilepsy in the SNAP25-Deficient Mouse Mutant Coloboma J. Neurosci., June 2, 2004; 24(22): 5239 - 5248. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Song, D. Kim, S. Choi, M. Sun, Y. Kim, and H.-S. Shin Role of the {alpha}1G T-Type Calcium Channel in Spontaneous Absence Seizures in Mutant Mice J. Neurosci., June 2, 2004; 24(22): 5249 - 5257. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Xu, A. Welling, S. Paparisto, F. Hofmann, and N. Klugbauer Enhanced Expression of L-type Cav1.3 Calcium Channels in Murine Embryonic Hearts from Cav1.2-deficient Mice J. Biol. Chem., October 17, 2003; 278(42): 40837 - 40841. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. T. Bello, K. L. Sweigart, J. M. Lakoski, R. Norgren, and A. Hajnal Restricted feeding with scheduled sucrose access results in an upregulation of the rat dopamine transporter Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2003; 284(5): R1260 - R1268. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Racz, A. Bilkei-Gorzo, Z. E. Toth, K. Michel, M. Palkovits, and A. Zimmer A Critical Role for the Cannabinoid CB1 Receptors in Alcohol Dependence and Stress-Stimulated Ethanol Drinking J. Neurosci., March 15, 2003; 23(6): 2453 - 2458. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Khan and H. A. Jinnah Paroxysmal Dyskinesias in the Lethargic Mouse Mutant J. Neurosci., September 15, 2002; 22(18): 8193 - 8200. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. E. Pizoli, H. A. Jinnah, M. L. Billingsley, and E. J. Hess Abnormal Cerebellar Signaling Induces Dystonia in Mice J. Neurosci., September 1, 2002; 22(17): 7825 - 7833. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Zhang, M. Mori, D. L. Burgess, and J. L. Noebels Mutations in High-Voltage-Activated Calcium Channel Genes Stimulate Low-Voltage-Activated Currents in Mouse Thalamic Relay Neurons J. Neurosci., August 1, 2002; 22(15): 6362 - 6371. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. L. Eagleson, L. D. Fairfull, S. R. J. Salton, and P. Levitt Regional Differences in Neurotrophin Availability Regulate Selective Expression of VGF in the Developing Limbic Cortex J. Neurosci., December 1, 2001; 21(23): 9315 - 9324. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Felix Channelopathies: ion channel defects linked to heritable clinical disorders J. Med. Genet., October 1, 2000; 37(10): 729 - 740. [Abstract] [Full Text] |
||||
![]() |
J. J. Plomp, M. N. Vergouwe, A. M. Van den Maagdenberg, M. D. Ferrari, R. R. Frants, and P. C. Molenaar Abnormal transmitter release at neuromuscular junctions of mice carrying the tottering {alpha}1A Ca2+ channel mutation Brain, March 1, 2000; 123(3): 463 - 471. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Jun, E. S. Piedras-Renteria, S. M. Smith, D. B. Wheeler, S. B. Lee, T. G. Lee, H. Chin, M. E. Adams, R. H. Scheller, R. W. Tsien, et al. Ablation of P/Q-type Ca2+ channel currents, altered synaptic transmission, and progressive ataxia in mice lacking the alpha 1A-subunit PNAS, December 21, 1999; 96(26): 15245 - 15250. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. F. Fletcher and WayneN. Frankel Ataxic mouse mutantsand molecular mechanisms of absence epilepsy Hum. Mol. Genet., September 1, 1999; 8(10): 1907 - 1912. [Abstract] [Full Text] [PDF] |
||||