Paraventricular thalamus: Gateway to feeding, appetitive motivation, and drug addiction

This chapter reviews the anatomical and functional evidence demonstrating the contribution of the paraventricular thalamic nucleus (PVT) to appetitive motivation, food intake control, and drug-seeking behaviors. We first consider the anatomical properties of the PVT to highlight its relevance in the control of appetitive motivation, feeding, and drug seeking. This is followed by a review of the available literature on PVT neurocircuitry, PVT involvement in food intake control, animal models of drug self-administration, withdrawal, and relapse. We show that PVT occupies a strategic position as a major thalamic interface between hindbrain and hypothalamic regions for viscerosensation and energy states; and between amygdala, cortical, and ventral striatal regions for motivation, reward, and learning. Understanding the precise anatomical and functional organization of these trans-PVT pathways remains a key challenge. Nonetheless, we show that PVT may be profitably viewed as the thalamic gateway to appetitive motivation, feeding, and drug addiction allowing both bottom-up (from brainstem and hypothalamus) and top-down (from cortex) control over reward and motivation.