Electrophysiological Monitoring of the Interactions Between the Serotonin and Dopamine Systems During Goal Directed Behaviors

摘要

The goal of this project is to record activity of serotonin and dopamine neurons during goal directed behavior. During this project we have overcome number of technical hurdles in order to successfully record neural activity of neurons within the raphe nuclei of behaving rats. Contrary to earlier studies that reported mainly tonic long timescale changes in firing rates, we found that raphe neurons phasically respond to task events on a short timescale of milliseconds during various phases of the task spanning sensory, motor and reward related processes. We are encouraged by these results and are confident that this approach of recording from raphe neurons during goal directed behaviors will provide a new understanding on function of serotonin in aspects of cognition, emotion and behavior. We now plan to investigate raphe neuronal responses during specific behaviors requiring serotonin function such as delayed reinforcement and reversal learning. We also plan to study interaction between raphe neuronal firing and sniffing and other motor behaviors. Having established the technically challenging raphe recording technique we can now perform dual serotonin and dopamine neuron recordings during goal directed behavior. Together, these studies are likely to provide insights into how disruption of normal Da/5HT function leads to motor and motivational impairments seen in Parkinson's Disease.