Ventral Pallidum

Anatomy

• In the basal forebrain, below the anterior commissure, ventral to the globus pallidus and behind the nucleus accumbens.
• Receives the GABAergic output of the ventral striatum (accumbens); its output goes to the mediodorsal thalamus, lateral habenula, VTA and lateral hypothalamus.
• Intermingled with the cholinergic neurons of the basal forebrain (nucleus basalis of Meynert).

Functions

• Hedonic “liking”: an opioid hot spot enhances the liking response to sweet tastes (Berridge and Kringelbach, 2015).
• Turning motivation into action: part of the limbic loop (accumbens → VP → mediodorsal thalamus → PFC).
• Social bonding: in prairie voles, vasopressin V1a receptors in the ventral pallidum take part in pair-bond formation (Lim et al., 2004); oxytocin acts mainly through the nucleus accumbens.

Connections and chemistry

• Nucleus accumbens → ventral pallidum (GABA, enkephalin)
• Ventral pallidum → mediodorsal thalamus → PFC (limbic loop)
• Ventral pallidum ↔ VTA, lateral habenula, lateral hypothalamus
• μ-opioid, GABA and vasopressin (V1a) receptors

Development

Developmental course through childhood and adolescence.

• As part of the reward circuit it is thought to contribute to the rise in reward sensitivity in adolescence; direct developmental data are limited.

Clinical

• Anhedonia and depression: reduced function in hedonic circuits.
• Substance use disorders: the VP plays a role in reinstatement of drug seeking (relapse) (animal studies).

Assessment

Neuropsychological tasks and measures that probe this region's function.

• Hedonic taste reactions (research)
• fMRI tasks separating the anticipation and consumption phases of reward

Lesions and damage

Clinical findings expected with damage or dysfunction.

• In animals, VP lesions can turn the liking response to sweetness into disgust.

In the model

How this structure is defined in the 3D model, and the data source.

CIT168 ventral pallidum probability map (right/left).

References

Full citations for the card; links go to the paper (DOI) or a PubMed search.

1. Berridge KC, Kringelbach ML. Pleasure systems in the brain. Neuron 2015;86(3):646–664. DOI: 10.1016/j.neuron.2015.02.018
2. Lim MM et al. Enhanced partner preference in a promiscuous species by manipulating the expression of a single gene. Nature 2004;429:754–757. DOI: 10.1038/nature02539