Tottering mouse motor dysfunction is abolished on the Purkinje cell degeneration (pcd) mutant background

Exp Neurol. 1999 Nov;160(1):268-78. doi: 10.1006/exnr.1999.7171.


Tottering (tg) mice inherit a recessive mutation of the calcium channel alpha 1A subunit gene, which encodes the pore-forming protein of P/Q-type voltage-sensitive calcium channels and is predominantly expressed in cerebellar granule and Purkinje neurons. The phenotypic consequences of the tottering mutation include ataxia, polyspike discharges, and an intermittent motor dysfunction best described as paroxysmal dystonia. These dystonic episodes induce c-fos mRNA expression in the cerebellar circuitry, including cerebellar granule and Purkinje neurons, deep cerebellar nuclei, and the postsynaptic targets of the deep nuclei. Cellular abnormalities associated with the mutation include hyperarborization of brainstem nucleus locus ceruleus axons and abnormal expression of L-type calcium channels in cerebellar Purkinje cells. Here, the role of these two distinct neural pathways in the expression of tottering mouse intermittent dystonia was assessed. Lesion of locus ceruleus axons with the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzyl-amine (DSP-4) did not affect the frequency of tottering mouse dystonic episodes. In contrast, removal of cerebellar Purkinje cells with the Purkinje cell degeneration (pcd) mutation by generation of tg/tg; pcd/pcd double mutant mice completely eliminated tottering mouse dystonia. Further, the c-fos expression pattern of tg/tg; pcd/pcd double mutants following restraint was indistinguishable from that of wild-type mice, suggesting that the pcd lesion eliminated an essential link in this abnormal neural network. These data suggest that the cerebellar cortex, where the mutant gene is abundantly expressed, contributes to the expression of tottering mouse dystonic episodes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Benzylamines / pharmacology
  • Calcium Channels / deficiency
  • Calcium Channels / genetics
  • Calcium Channels / physiology*
  • Calcium Channels, L-Type / metabolism
  • Calcium Channels, N-Type
  • Calcium Channels, P-Type
  • Calcium Channels, Q-Type
  • Cerebellar Ataxia / genetics
  • Cerebellar Ataxia / metabolism
  • Cerebellar Ataxia / pathology*
  • Cerebellar Cortex / drug effects
  • Cerebellar Cortex / pathology*
  • Dystonia / genetics
  • Dystonia / metabolism
  • Dystonia / pathology*
  • Genes, fos
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Hippocampus / pathology
  • In Situ Hybridization
  • Locus Coeruleus / drug effects
  • Locus Coeruleus / metabolism
  • Locus Coeruleus / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Neurologic Mutants
  • Nerve Degeneration*
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Neurotoxins / pharmacology
  • Purkinje Cells / metabolism
  • Purkinje Cells / pathology*
  • RNA, Messenger / metabolism


  • Benzylamines
  • Calcium Channels
  • Calcium Channels, L-Type
  • Calcium Channels, N-Type
  • Calcium Channels, P-Type
  • Calcium Channels, Q-Type
  • Nerve Tissue Proteins
  • Neurotoxins
  • RNA, Messenger
  • voltage-dependent calcium channel (P-Q type)
  • DSP 4