摘要
Excessive theta(θ)frequency oscillation and synchronization in the basal ganglia(BG)has been reported in elderly parkinsonian patients and animal models of levodopa(L-dopa)-induced dyskinesia(LID),particularly theθoscillation recorded during periods when L-dopa is withdrawn(the off L-dopa state).To gain insight into processes underlying this activity,we explored the relationship between primary motor cortex(M1)oscillatory activity and BG output in LID.We recorded local field potentials in the substantia nigra pars reticulata(SNr)and M1 of awake,inattentive resting rats before and after L-dopa priming in Sham control,Parkinson disease model,and LID model groups.We found that chronic L-dopa increasedθsynchronization and information flow between the SNr and M1 in off L-dopa state LID rats,with a SNr-to-M1 flow directionality.Compared with the on state,θoscillational activity(θsynchronization and informationflow)during the off state were more closely associated with abnormal involuntary movements.Our findings indicate thatθoscillation in M1 may be consequent to abnormal synchronous discharges in the BG and support the notion that M1θoscillation may participate in the induction of dyskinesia.
基金
supported by the National Natural Science Foundation of China(81771210)
the Natural Science Foundation of Guangdong Province,China(2015A030313288)。