Date:2010
Author:Suzanne N Haber*1 and Brian Knutson2
Pages:23
Summary:The article "The Reward Circuit: Linking Primate Anatomy and Human Imaging" by Suzanne N. Haber and Brian Knutson reviews the key structures and pathways involved in the reward system, focusing on the cortical-basal ganglia circuit. The core structures include the anterior cingulate cortex, orbital prefrontal cortex, ventral striatum, ventral pallidum, and midbrain dopamine neurons. Other structures like the amygdala, hippocampus, thalamus, and lateral habenular nucleus also play crucial roles. Advances in neuroimaging techniques have improved spatial and temporal resolution, allowing for better mapping of human functional and structural imaging results to primate anatomy.
The authors discuss the historical development of the concept of the reward circuit, highlighting the work of Olds and Milner, who demonstrated that rats would work for electrical stimulation in specific brain sites. They also review the role of the nucleus accumbens (NAcc) and ventral tegmental area (VTA) dopamine neurons in the reward system. Recent studies have shown that the striatal and midbrain areas involved in reward are more extensive than previously thought, including the entire ventral striatum (VS) and the substantia nigra (SN).
The article delves into the organization and function of the prefrontal cortex, particularly the orbital prefrontal cortex (OFC) and ventral medial prefrontal cortex (vmPFC), which are key regions for reward processing. Neuroimaging studies have shown that various types of rewards, both primary and secondary, increase activity in these regions. The vmPFC is particularly implicated in processing diverse and abstract rewards, while the dorsal anterior cingulate cortex (dACC) and dorsal prefrontal cortex (dPFC) play important roles in reward processing through conflict monitoring and working memory.
The ventral striatum (VS) is another critical component of the reward circuit, receiving dense projections from the vmPFC, OFC, dACC, and dPFC. The VS includes the NAcc and broader regions of the caudate nucleus and putamen. The VS receives input from the amygdala and hippocampus, making it a key entry point for emotional and motivational information. Neuroimaging studies have shown that striatal activation increases during reward processing, with the NAcc showing preferential activation during anticipation of monetary gains.
The article also explores the integration of information within the VS, suggesting that different aspects of anticipated reward, such as magnitude, probability, uncertainty, delay, and effort, may be processed in distinct subcomponents of the VS. For example, the NAcc responds to anticipated reward magnitude, while the rostroventral putamen may be more sensitive to probability and effort.
Overall, the article provides a comprehensive overview of the anatomical and functional aspects of the reward circuit, highlighting the complex interactions between different brain regions and the importance of neuroimaging techniques in understanding these processes.