Dystonia is a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures. Dystonia can be classified by etiology into primary (or idiopathic) and secondary (or symptomatic). The etiology in most cases of dystonia is idiopathic. Idiopathic dystonic may be inherited or sporadic in occurrence. Family members of patients with inherited, idiopathic, generalized dystonia may have generalized, segmental or focal dystonia and generalized dystonia typically begins focally suggesting that the idiopathic dystonias may have a common pathophysiology. Postmortem pathologic examination and magnetic resonance imaging have been unrevealing in patients with idiopathic dystonia. Neurochemical study of postmortem brains from a few patients with idiopathic dystonia has demonstrated abnormalities in serotonin and norepinephrine levels in various brain regions. However, it is not clear whether or not these abnormalities are merely epiphenomenal. The dystonic (dt) rat is an autosomal recessive mutant with a motor syndrome that closely resembles the generalized dystonia seen in humans. The dystonic rat undergoes a period of normal development prior to the emergence of a motor syndrome characterized by twisting of the axial musculature and limbs. The nervous system is normal on examination with light microscopy and the abnormal movements are reduced or absent with rest. The features of the dystonic rat suggest that it may be a useful model of idiopathic, generalized dystonia and possibly idiopathic dystonia in general. In the dystonic rat marked biochemical and physiological abnormalities have been isolated to the olivo-cerebellar pathways.
The specific aims of the research proposal are to further characterize the abnormalities in the dt rat olivo-cerebellar pathways and to determine the importance of cerebellar outflow in the generation of the dt rat motor syndrome. The three neuron loop from the inferior olive to the Purkinje cells of cerebellar cortex to the deep cerebellar nuclei will be examined systematically, beginning with the inferior olive. Biochemical and physiological findings in this species may provide insight into human dystonia.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08NS001593-02
Application #
2259558
Study Section
NST-2 Subcommittee (NST)
Project Start
1992-12-01
Project End
1997-11-30
Budget Start
1993-12-01
Budget End
1994-11-30
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Alabama Birmingham
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
004514360
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Xiao, Jianfeng; Vemula, Satya R; LeDoux, Mark S (2014) Recent advances in the genetics of dystonia. Curr Neurol Neurosci Rep 14:462
LeDoux, Mark S (2011) Animal models of dystonia: Lessons from a mutant rat. Neurobiol Dis 42:152-61
LeDoux, Mark S; Lorden, Joan F (2002) Abnormal spontaneous and harmaline-stimulated Purkinje cell activity in the awake genetically dystonic rat. Exp Brain Res 145:457-67
Kim, H S; Hong, S J; LeDoux, M S et al. (2001) Regulation of the tyrosine hydroxylase and dopamine beta-hydroxylase genes by the transcription factor AP-2. J Neurochem 76:280-94
LeDoux, M S; Lorden, J F (1998) Abnormal cerebellar output in the genetically dystonic rat. Adv Neurol 78:63-78
LeDoux, M S; Hurst, D C; Lorden, J F (1998) Single-unit activity of cerebellar nuclear cells in the awake genetically dystonic rat. Neuroscience 86:533-45
LeDoux, M S; Rutledge, S L; Mountz, J M et al. (1995) SPECT abnormalities in generalized dystonia. Pediatr Neurol 13:5-10
LeDoux, M S; Lorden, J F; Meinzen-Derr, J (1995) Selective elimination of cerebellar output in the genetically dystonic rat. Brain Res 697:91-103
Ledoux, M S; Lorden, J F; Ervin, J M (1994) Inferior olive serotonin and norepinephrine levels during development in the genetically dystonic rat. Brain Res Bull 33:299-305