The article provides a comprehensive overview of the microcircuitry and functional roles of the nucleus accumbens (NAc) and the ventral tegmental area (VTA) in the cortico-basal ganglia reward network. The NAc, a key structure in integrating limbic and motor-related information, receives extensive excitatory inputs from the prefrontal cortex, hippocampus, and amygdala, and inhibitory inputs from the ventral pallidum. Dopamine neurons in the VTA modulate NAc activity, influencing goal-directed behavior and reward processing. The VTA projects to various forebrain regions, including the NAc, and plays a crucial role in facilitating approach behaviors and incentive learning. The article also discusses the interaction between hippocampal and prefrontal inputs to the NAc, highlighting the role of the VTA in reward learning and the transition from reinforcement to habit formation. The findings underscore the importance of the cortico-basal ganglia reward network in shaping adaptive behaviors and its vulnerability to disruptions in conditions such as addiction and psychiatric disorders.The article provides a comprehensive overview of the microcircuitry and functional roles of the nucleus accumbens (NAc) and the ventral tegmental area (VTA) in the cortico-basal ganglia reward network. The NAc, a key structure in integrating limbic and motor-related information, receives extensive excitatory inputs from the prefrontal cortex, hippocampus, and amygdala, and inhibitory inputs from the ventral pallidum. Dopamine neurons in the VTA modulate NAc activity, influencing goal-directed behavior and reward processing. The VTA projects to various forebrain regions, including the NAc, and plays a crucial role in facilitating approach behaviors and incentive learning. The article also discusses the interaction between hippocampal and prefrontal inputs to the NAc, highlighting the role of the VTA in reward learning and the transition from reinforcement to habit formation. The findings underscore the importance of the cortico-basal ganglia reward network in shaping adaptive behaviors and its vulnerability to disruptions in conditions such as addiction and psychiatric disorders.