The ventral pallidum (VP) is a structure within the

basal ganglia The basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an extern ...

of the

brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...

. It is an output nucleus whose fibres project to

thalamic The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...

nuclei, such as the

ventral anterior nucleus The ventral anterior nucleus (VA) is a nucleus of the thalamus. It acts with the anterior part of the ventral lateral nucleus to modify signals from the basal ganglia. Inputs and outputs The ventral anterior nucleus receives neuronal inputs from t ...

, the

ventral lateral nucleus The ventral lateral nucleus (VL) is a nucleus in the ventral nuclear group of the thalamus. Inputs and outputs It receives neuronal inputs from the basal ganglia which includes the substantia nigra and the globus pallidus (via the thalamic fas ...

, and the

medial dorsal nucleus The medial dorsal nucleus (or dorsomedial nucleus of thalamus) is a large nucleus in the thalamus. It is believed to play a role in memory. Structure It relays inputs from the amygdala and olfactory cortex and projects to the prefrontal cortex a ...

. The VP is a core component of the

reward system The reward system (the mesocorticolimbic circuit) is a group of neural structures responsible for incentive salience (i.e., "wanting"; desire or craving for a reward and motivation), associative learning (primarily positive reinforcement and cl ...

which forms part of the limbic loop of the basal ganglia, a pathway involved in the regulation of motivational salience, behavior, and emotions. It is involved in

addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use oft ...

. The VP contains one of the brain's pleasure centers, which mediates the subjective perception of

pleasure Pleasure refers to experience that feels good, that involves the enjoyment of something. It contrasts with pain or suffering, which are forms of feeling bad. It is closely related to value, desire and action: humans and other conscious anima ...

that results from "consuming" certain rewarding stimuli (e.g., palatable food).

Anatomy

The ventral pallidum lies within the

, a group of subcortical nuclei. Along with the external globus pallidus, it is separated from other basal ganglia nuclei by the

anterior commissure The anterior commissure (also known as the precommissure) is a white matter tract (a bundle of axons) connecting the two temporal lobes of the cerebral hemispheres across the midline, and placed in front of the columns of the fornix. In most exist ...

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 pars reticulata The pars reticulata (SNpr) is a portion of the substantia nigra and is located lateral to the pars compacta. Most of the neurons that project out of the pars reticulata are inhibitory GABAergic neurons (i.e., these neurons release GABA, which i ...

) receives input from the temporal lobes, and the

hippocampus The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ...

via the

ventral striatum The striatum, or corpus striatum (also called the striate nucleus), is a nucleus (a cluster of neurons) in the subcortical basal ganglia of the forebrain. The striatum is a critical component of the motor and reward systems; receives glutama ...

. The information is relayed to the medial dorsal and ventral anterior nuclei of the thalamus.

Role in addiction

The ventral pallidum doesn't receive dopaminergic inputs from the

ventral tegmental area The ventral tegmental area (VTA) (tegmentum is Latin for ''covering''), also known as the ventral tegmental area of Tsai, or simply ventral tegmentum, is a group of neurons located close to the midline on the floor of the midbrain. The VTA is th ...

. The ventral pallidum receives

GABAergic In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter GABA. For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic neuron produces GABA. A ...

inputs from the

nucleus accumbens The nucleus accumbens (NAc or NAcc; also known as the accumbens nucleus, or formerly as the ''nucleus accumbens septi'', Latin for "nucleus adjacent to the septum") is a region in the basal forebrain rostral to the preoptic area of the hypot ...

. It acts in part as a relay nucleus from the nucleus accumbens to the

. The nucleus accumbens projects to the medial dorsal nucleus via GABAergic

medium spiny neurons Medium spiny neurons (MSNs), also known as spiny projection neurons (SPNs), are a special type of GABAergic inhibitory cell representing 95% of neurons within the human striatum, a basal ganglia structure. Medium spiny neurons have two primary ...

. The rewarding effects of addictive drugs are mediated in part through their effect on the VP.

References

Additional Sources

* Martin J.H. Neuroanatomy Text and Atlas. 3rd Edition 2003: Chapter 14 {{DEFAULTSORT:Ventral pallidum Basal ganglia