Table of Contents

Dynamic Gain Control of Dopamine Delivery in Freely Moving Animals

  1. R. Mark Wightman3,4
  1. 1Human Neuroimaging Laboratory, Center for Theoretical Neuroscience, Division of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, and Departments of 2Psychology, 3Chemistry, and 4Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599

Abstract

Activity changes in a large subset of midbrain dopamine neurons fulfill numerous assumptions of learning theory by encoding a prediction error between actual and predicted reward. This computational interpretation of dopaminergic spike activity invites the important question of how changes in spike rate are translated into changes in dopamine delivery at target neural structures. Using electrochemical detection of rapid dopamine release in the striatum of freely moving rats, we established that a single dynamic model can capture all the measured fluctuations in dopamine delivery. This model revealed three independent short-term adaptive processes acting to control dopamine release. These short-term components generalized well across animals and stimulation patterns and were preserved under anesthesia. The model has implications for the dynamic filtering interposed between changes in spike production and forebrain dopamine release.

  • Received July 8, 2003.
  • Revision received November 18, 2003.
  • Accepted December 23, 2003.