Ventral striatum

The ventral striatum is the ventral functional region of the striatum and forms the principal input component of the ventral basal ganglia. Its boundaries are not sharply defined and vary according to the anatomical or functional criteria used. In the framework adopted by Humphries and Prescott, the ventral striatum is mostly composed of the nucleus accumbens and is often treated anatomically as synonymous with it. However, broader definitions may extend the ventral striatum beyond the nucleus accumbens to include adjacent striatal regions receiving prominent input from the hippocampal formation, particularly the subiculum. The paper notes that much of this anatomical framework is derived from animal studies, especially the rat.

Functionally, the ventral striatum is an important site of convergence of limbic and cortical information. It receives major inputs from the hippocampal formation, amygdala and prefrontal cortex, together with strong dopaminergic modulation. These inputs broadly provide information about spatial and environmental context, the significance or value of stimuli, behavioural goals and strategies, and learning-related signals.

Through these connections, the ventral striatum contributes to the learning and selection of flexible, goal-directed behaviours, particularly when behaviour must be adjusted according to location, expected outcomes, environmental cues and changing circumstances. Thus, it should not simply be described as a “reward centre”; rather, it integrates information about context, value and behavioural strategy to help select appropriate behaviour.