Acute drug induced parkinsonian akinesia is associated with reduced rate and increased regularity of neuronal activity in the pedunculopontine tegmental nucleus of unanesthetized rats

The pedunculopontine tegmental nucleus of the brainstem is important for a wide range of functions, including sensorimotor integration and regulation of locomotion and discrete forelimb movements. Evidence suggests it is structurally disordered as part of the neuropathology of the movement disorder Parkinson’s disease. To assess whether neuronal activity is also affected in parkinsonian model animals we used single neuron recordings in free moving rats to determine the effects of acute drug-induced parkinsonism on the firing rate of the neurons. Acute parkinsonian akinesia was associated with reduction in resting firing rate and increased firing regularity, consistent with reduced excitability in this state.