Functional convergence of parallel circuits within subthalamic nucleus: Intra-operative multichannel-microelectrode recording study during emotional, cognitive and motor tasks

Abstract

Objective: Demonstrate the convergence of circuit loops of basal ganglia within STN. Background: Specific cortical areas involved in the processing of motor, cognitive and emotional information are connected through parallel circuits to separate territories within basal ganglia suggesting a segregated model of information processing. However, behavioral changes in PD patients after STN DBS in the same subjects who experienced significant motor improvement suggest that the greatest convergence of different circuit loops is reached within STN. Methods: Twelve consecutive PD patients underwent multiunit recording through a 32-channel-microelectrode based in an assembly of microwires used for electrophysiological mapping of STN during stereotactic implantation of DBS electrodes in standard dorsolateral STN target. Once, the neurophysiologist recognized the neuron activity pattern typical of STN, the patient was asked to perform the tasks. Neuronal signal recording was time-locked with the interactive workstation that presented emotional valence images (IAPS Image Bank), a decision-making task and motion performance analysis of the contralateral hand. The signal was submitted to off-line spike-sorting analysis and correlated to behavioral responses to the three-modality tasks. Results: Twelve consecutive PD patients underwent multiunit recording through a 32-channel-microelectrode based in an assembly of microwires used for electrophysiological mapping of STN during stereotactic implantation of DBS electrodes in standard dorsolateral STN target. Once, the neurophysiologist recognized the neuron activity pattern typical of STN, the patient was asked to perform the tasks. Neuronal signal recording was time-locked with the interactive workstation that presented emotional valence images (IAPS Image Bank), a decision-making task and motion performance analysis of the contralateral hand. The signal was submitted to off-line spike-sorting analysis and correlated to behavioral responses to the three-modality tasks. Conclusions: This data is consistent with the hypothesis the basal ganglia modulates motor activity as complex behavioral series that are strongly influenced by the cognitive and emotional context in which they are executed.