The nucleus accumbens (NAc) (colloquially known as the pleasure center) is a small region in the forebrain below the corpus striatum. It is involved in the reward pathway and is therefore involved in impulse control disorders.
- It is located in the basal ganglia below the corpus striatum
- It is involved in the reward pathway
- It receives vascular supply from the medial lenticulostriate arteries
- It is connected to the ventral tegmental area (VTA), the prefrontal cortex (PFC), basolateral amygdala (BLA) and the lateral hypothalamus (LH)
The NAc is part of the basal ganglia. It is not a separate structure and hence cannot be identified distinctly on cerebral specimen.
There appears to be ambiguity in terms of its relationship with the ventral striatum as some sources identify that the NAc was formerly known as the ventral striatum, while others identify it as a part of the ventral striatum 1,2.
The NAc receives dopaminergic innervation from the VTA in the brainstem, glutaminergic from the PFC and orexinergic innervation from the LH 2.
The predominant role of the NAc is to influence planning and aversion based on pleasurable stimuli. This information is conveyed to the PFC, LH and the brain stem 1,2.
Dopaminergic innervation from the VTA and glutaminergic innervation from the PFC are responsible for the reward pathway for food, sex and music. The NAc also receives orexinergic projections from the LH which are thought to model the psychosomatic response to psycostimulant drugs 3.
The NAc receives blood supply from the recurrent artery of Heubner, which is a branch of the medial lenticulostraite arteries 4.
The NAc is quite small to be visualized on MRI. Other features that make it difficult to visualize the NAc are its proximity to the cerebral sinuses and pulsating arterioles.
On fMRI, the NAc is activated when patients actively crave pleasurable stimuli and it is inactivated when the stimuli has been received 5.
- 1. P. Michael Conn. Conn's Translational Neuroscience. (2016) ISBN: 9780128025963
- 2. A.B. Christine, A.EckhardtKay M.Tye. Deciphering Memory Function with Optogenetics. Progress in Molecular Biology and Translational Science. ISBN: 9780124201705
- 3. Haghparast, Abbas, et al. Functional roles of orexin/hypocretin receptors in reward circuit. Progress in brain research. Vol. 235. Elsevier, 2017. 139-154. ISBN: 9780128135013
- 4. El Falougy, Hisham, Selmeciova, Petra, Kubikova, Eliska, Haviarová, Zora. The Variable Origin of the Recurrent Artery of Heubner: An Anatomical and Morphometric Study. (2018) BioMed Research International. 2013: 873434. doi:10.1155/2013/873434 - Pubmed
- 5. C.A.HanlonL.T.DowdleJ.L.Jones. Biomarkers for Success: Using Neuroimaging to Predict Relapse and Develop Brain Stimulation Treatments for Cocaine-Dependent Individuals. International Review of Neurobiology ISBN: 9780128123812