Characteristics of Single-Unit and Network Activity of Neurons in the Subthalamic Nucleus on Production of Impulsive and Delayed (self-controlled) Responses in Conditions of Reinforcement Choice

摘要

Experiments on cats addressed neuron activity in the subthalamic nucleus (STN) during different types of behavior in a situation of choosing reinforcement in relation to its value and availability. Chronic experiments were performed to record neuron activity in the subthalamic nucleus and orbitofrontal cortex and to analyze neuron activity in terms of frequency and network properties. Neurons in the subthalamic nucleus were found to respond with acceleration or suppression of discharge activity to both the conditioned stimulus and reinforcements of different value. However, a given subthalamic nucleus neuron could respond with increases in activity frequency to the expectation of a bread/meat mix and a decrease in the activity frequency to expectation of meat. The number of cross-correlational excitatory links between neurons in the subthalamic nucleus was found to be signifi cantly greater in when the choice was for impulsive behavior than for self-controlled behavior. The number of cross-correlational links between cells in the orbitofrontal cortex and subthalamic nucleus with intervals over the range 0–30 msec was signifi cantly greater on appearance of impulsive than self-controlled behavior. The electrophysiological results obtained here provide support for the suggestion that the STN is involved in organizing networks associated with taking decisions regarding selection of impulsive or self-controlled behavior.