The electrical activity is impaired in the red nucleus of dt sz mutant hamsters with paroxysmal dystonia: an EEG power spectrum analysis of depth electrode recordings

Abstract

The genetically dystonic ( dt sz ) hamster is an animal model of paroxysmal dystonia that displays attacks of sustained abnormal movements and postures in response to mild stress. Dysfunctions within the basal ganglia may be critically involved in the pathophysiology of dystonia in mutant hamsters. Furthermore, previous observations from autoradiographic studies pointed to an altered neural activity in the red nucleus (RN). In the present study, computerized EEG spectral analysis of depth electrode recordings from the RN was performed before and after dystonic attacks in freely moving dt sz hamsters and compared to age-matched non-dystonic controls. No epileptic activity was seen in any of the recordings, substantiating previous notions that paroxysmal dystonia in these mutants has no epileptogenic basis. The predominant EEG changes in RN of dystonic hamsters were a decrease in total power over the range of 1.25–42.00 Hz, a decrease in maximum power and a shift of frequency at maximum power to lower frequencies. With regard to selected frequency bands, there was a decrease in the α, β and γ band. Although the observed changes of neural activity in the RN are probably based on a primary dysfunction in related structures, the present data demonstrate its importance in the expression of dystonic movements.