Aberrant striatal oscillations after dopamine loss in parkinsonian non-human primates

Dopamine depletion in Parkinsons disease (PD) is associated with abnormal oscillatory activity in the cortico-basal ganglia network. However, the oscillatory pattern of striatal neurons in PD remains poorly defined. Here, we analyzed the local field potentials in one untreated and five MPTP-treated non-human primates (NHP) to model advanced PD. Augmented oscillatory activity in the alpha (8-13 Hz) and low-beta (13-20 Hz) frequency bands was found in the striatum in parallel to the motor cortex and globus pallidus of the NHP-PD model. The coherence analysis showed increased connectivity in the cortico-striatal and striato-pallidal pathways at alpha and low-beta frequency bands, confirming the presence of abnormal 8-20 Hz activity in the cortico-basal ganglia network. The acute L-Dopa injection that induced a clear motor response normalized the amplified 8-20 Hz oscillations. These findings indicate that pathological striatal oscillations at alpha and low-beta bands are concordant with the basal ganglia network changes after dopamine depletion, and thereby support a key role of the striatum in the generation of parkinsonian motor abnormalities.