FACTOID # 13: New York has America's lowest percentage of residents who are veterans.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Nucleus accumbens
Brain: Nucleus accumbens
Nucleus accumbens not labeled, but labels are provided for caudate, putamen, and septum pellucidum.
Medial surface. (Nucleus accumbens is very roughly in the area of the 34.)
Latin nucleus accumbens septi
NeuroNames hier-259
MeSH Nucleus+Accumbens
Dorlands/Elsevier n_11/12580142

The nucleus accumbens (NAcc), also known as the accumbens nucleus or as the nucleus accumbens septi (Latin for nucleus leaning against the septum), is a collection of neurons located where the head of the caudate and the anterior portion of the putamen meet just lateral to the septum pellucidum.
The nucleus accumbens can be divided into two structures -- the nucleus accumbens core and the nucleus accumbens shell. These structures have different morphology and function.
The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum, which is part of the basal ganglia [1]. Image File history File links Gray744. ... The caudate nucleus is a telencephalic nucleus, one of the input nuclei of the basal ganglia; involved with control of voluntary movement in the brain. ... The putamen is a structure in the middle of the brain, forming the striatum together with the caudate nucleus. ... The septum pellucidum, also called the septum lucidum, is a thin, triangular, vertical membrane that separates the lateral ventricles of the brain. ... Image File history File links Download high-resolution version (960x720, 212 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Entorhinal cortex Cingulate cortex Brodmann area Nucleus accumbens Brodmann area 24 Posterior cingulate ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... NeuroNames is a system of nomenclature for the brain and related structures. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo. ... In neuroanatomy, a nucleus is a central nervous system structure that is composed mainly of gray matter, and which acts as a hub or transit point for electrical signals in a single neural subsystem. ... Look up septum in Wiktionary, the free dictionary. ... Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ... The caudate nucleus is a telencephalic nucleus, one of the input nuclei of the basal ganglia; involved with control of voluntary movement in the brain. ... The putamen is a structure in the middle of the brain, forming the striatum together with the caudate nucleus. ... The septum pellucidum, also called the septum lucidum, is a thin, triangular, vertical membrane that separates the lateral ventricles of the brain. ... Young boy smelling a flower Olfaction, the sense of smell, is the detection of chemicals dissolved in air. ... Coronal slices of human brain showing the basal ganglia, the striatum and pallidum globus pallidus: external segment (GPe), subthalamic nucleus (STN), globus pallidus: internal segment (GPi), and substantia nigra (SN). ... The basal ganglia (or basal nuclei) are a group of nuclei in the brain interconnected with the cerebral cortex, thalamus and brainstem. ...


This nucleus is thought to play an important role in reward, laughter, pleasure, and addiction. “Happy” redirects here. ... An addiction is a recurring compulsion by an individual to engage in some specific activity. ...

Contents

Cell types

The principal neuronal cell type found in the nucleus accumbens is the medium spiny neuron. The neurotransmitter produced by these neurons is gamma-aminobutyric acid (GABA), one of the main inhibitory neurotransmitters of the central nervous system. These neurons are also the main projection or output neurons of the nucleus accumbens. The medium spiny neurons are a special type of inhibitory cells representing approximately 75% of the neurons within the corpus striatum of the basal ganglia. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... Gamma-aminobutyric acid (usually abbreviated to GABA) is an inhibitory neurotransmitter found in the nervous systems of widely divergent species. ...


While 95% of the neurons in the nucleus accumbens are medium spiny GABA-ergic projection neurons, other neuronal types are also found such as large aspiny cholinergic interneurons. A synapse is cholinergic if it uses acetylcholine as its neurotransmitter. ... An interneuron (also called relay neuron,association neuron or bipolar neuron) is a term used to describe a neuron which has two different common meanings. ...


Output and input

The output neurons of the nucleus accumbens send axon projections to the ventral analog of the globus pallidus, known as the ventral pallidum (VP). The VP, in turn, projects to the mediodorsal (MD) nucleus of the dorsal thalamus, which projects to the prefrontal cortex. Other efferents from the nucleus accumbens include connections with the substantia nigra and pontine reticular formation. Major inputs to the nucleus accumbens include prefrontal association cortices, basolateral amygdala, and dopaminergic neurons located in the ventral tegmental area (VTA), which connect via the mesolimbic pathway. Thus the nucleus accumbens is often described as one part of a cortico-striato-thalamo-cortical loop. The globus pallidus (Latin for pale body) is a sub-cortical structure in the brain. ... Coronal slices of human brain showing the basal ganglia, globus pallidus: external segment (GPe), subthalamic nucleus (STN), globus pallidus: internal segment (GPi), and substantia nigra (SN). ... The thalamus (from Greek θάλαμος = bedroom, chamber, IPA= /ˈθæləməs/) is a pair and symmetric part of the brain. ... The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas. ... The substantia nigra, (Latin for black substance, Soemering) or locus niger is a heterogeneous portion of the midbrain, separating the pes (foot) from the tegmentum (covering), and a major element of the basal ganglia system. ... Look up Amygdala in Wiktionary, the free dictionary. ... The ventral tegmentum or the ventral tegmental area (VTA) is part of the midbrain, lying close to the substantia nigra and the red nucleus. ... The mesolimbic pathway is one of the neural pathways in the brain that link the ventral tegmentum in the midbrain to the nucleus accumbens in the limbic system. ...


Dopaminergic input from the VTA is thought to modulate the activity of neurons within the nucleus accumbens. These terminals are also the site of action of highly-addictive drugs such as cocaine and amphetamine, which cause a manifold increase in dopamine levels in the nucleus accumbens. In addition to cocaine and amphetamine, almost every drug abused by humans has been shown to increase dopamine levels in the nucleus accumbens. This article does not cite its references or sources. ... Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. ... Amphetamine or Amfetamine (Alpha-Methyl-PHenEThylAMINE), also known as, beta-phenyl-isopropylamine, and benzedrine, is a prescription stimulant commonly used to treat Attention-deficit hyperactivity disorder (ADHD) in adults and children. ... Dopamine is a phenethylamine naturally produced by the human body. ...


Research

In the 1950s, Olds and Milner implanted electrodes into the septal area of the rat and found that the rat chose to press a lever which stimulated it. It continued to prefer this even over stopping to eat or drink. This suggests that the area is the 'pleasure center' of the brain.[2]


Although the nucleus accumbens has traditionally been studied for its role in addiction, it plays an equal role in processing many rewards such as food, sex, and video games. A recent study found that it is involved in the regulation of emotions induced by music [3] , perhaps consequent to its role in mediating dopamine release. It also has roles in timing, and has long been considered to be the limbic-motor interface (Mogensen). // Music is an art form consisting of sound and silence expressed through time. ...


References

  1. ^ http://www.nlm.nih.gov/cgi/mesh/2007/MB_cgi?mode=&term=Nucleus+Accumbens
  2. ^ Olds J, Milner P (1954). "Positive reinforcement produced by electrical stimulation of septal area and other regions of rat brain". J Comp Physiol Psychol 47 (6): 419-27. PMID 13233369.  article
  3. ^ Menon, Vinod & Levitin, Daniel J. (2005) The rewards of music listening: Response and physiological connectivity of themesolimbic system." NeuroImage 28(1), pp. 175-184

External links


  Results from FactBites:
 
Nucleus accumbens - Wikipedia, the free encyclopedia (424 words)
The nucleus accumbens (also known as the accumbens nucleus or nucleus accumbens septi) is a collection of neurons located where the head of the caudate and the anterior portion of the putamen meet just lateral to the septum pellucidum.
The name “nucleus accumbens septi” is derived from the Latin phrase meaning “nucleus leans against the septum”.
The output neurons of the nucleus accumbens send axon projections to the ventral analog of the globus pallidus known as the ventral pallidum (VP).
Gestational Nicotine Exposure Attenuates Nicotine-Stimulated Dopamine Release in the Nucleus Accumbens Shell of ... (5072 words)
accumbens dopamine response to 0.07 mg/kg nicotine i.v.
Nucleus accumbens dopamine release in response to 0.105 mg/kg i.v.
nucleus accumbens dopamine responses to 0.07 mg/kg nicotine
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m