The ventral pallidum ( VP) is a structure within the basal ganglia of the brain. It is an output nucleus whose fibres project to thalamus nuclei, such as the ventral anterior nucleus, the ventral lateral nucleus, and the medial dorsal nucleus.
The VP is a core component of the reward system which forms part of the limbic loop of the basal ganglia,
The VP contains one of the brain's pleasure centers, which mediates the subjective perception of pleasure that results from "consuming" certain rewarding stimuli (e.g., palatable food).
Anatomy
The ventral pallidum lies within the
basal ganglia, a group of subcortical nuclei. Along with the external globus pallidus, it is separated from other basal ganglia nuclei by the anterior commissure.
The ventral pallidum contains GABAergic neurons, glutamatergic neurons, and cholinergic neurons that are well conserved across mammals.
Limbic loop
The limbic loop is a functional pathway of the basal ganglia, in which the ventral pallidum is involved. It (and the internal globus pallidus and
Substantia Nigra) receives input from the
temporal lobes, and the
hippocampus via the
ventral striatum. The information is relayed to the medial dorsal and ventral anterior nuclei of the thalamus.
Role in addiction
It is unclear whether the ventral pallidum receives dopaminergic inputs from the ventral tegmental area.
The ventral pallidum receives
GABAergic inputs from the nucleus accumbens.
It acts in part as a relay nucleus from the nucleus accumbens to the medial dorsal nucleus. The nucleus accumbens projects to the medial dorsal nucleus via GABAergic medium spiny neurons. The rewarding effects of addictive drugs are mediated in part through their effect on the VP.
Additional Sources
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Martin J.H. Neuroanatomy Text and Atlas. 3rd Edition 2003: Chapter 14
