Phase response analysis of a morphological globus pallidus neuron model during irregular spiking: intrinsic and synaptic mechanisms

Abstract

Introduction Recent evidence suggests a prominent role for the globus pallidus (GP) in the synchronization of basal ganglia oscillatory activity associated with Parkinson's disease. The emergence of synchronous network activity is strongly influenced by the character of the phase response curve (PRC) that describes how a rhythmically spiking neuron responds to synaptic inputs by advancing or delaying the next spike. The PRC for dendritic inputs (dPRC) to GP contains both positive and negative regions, indicating that excitatory dendritic input can either advance or delay the next spike depending on when it occurs during the intrinsic spike rhythm. However, in vivo GP neurons receive stochastic backgrounds of synaptic input that drive irregular spiking. In this study, we investigated the interaction of stochastic synaptic backgrounds with intrinsic currents in the dendritic membrane of a morphologically realistic GP neuron model to assess how in vivo-like high conductance states affect dendritic phase response properties.