Abstract
Recording neuronal activity in animal models give us important clues to understand the pathophysiology of movement disorders. Dystonia is one of the basal ganglia disorders characterized by sustained or repetitive involuntary muscle contractions and abnormal postures. A major group of early-onset generalized dystonia arises from a mutation in the DYT1 gene, which encodes torsinA protein. To understand the pathophysiology of dystonia, we recorded neuronal activity of basal ganglia in a mouse model overexpressing mutant torsinA, in awake state. Reduced spontaneous activity with bursts and pauses were observed in both the internal (GPi) and external segments of the globus. Motor cortical stimulation evoked abnormal responses with long-lasting inhibition, which were never observed in the normal mice. In addition, somatotopic arrangements in both pallidal segments were disorganized. Long-lasting inhibition induced by cortical inputs in GPi may disinhibit thalamic and cortical activity, resulting in the involuntary movements observed in the mouse model.
