Dopamine receptor
Encyclopedia
Dopamine receptors are a class of metabotropic
Metabotropic receptor
Metabotropic receptor is a subtype of membrane receptors at the surface or in vesicles of eukaryotic cells.In the nervous system, based on their structural and functional characteristics, neurotransmitter receptors can be classified into two broad categories: metabotropic and ionotropic receptors...

 G protein-coupled receptor
G protein-coupled receptor
G protein-coupled receptors , also known as seven-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors , comprise a large protein family of transmembrane receptors that sense molecules outside the cell and activate inside signal...

s that are prominent in the vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

 central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 (CNS). The neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

 dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

 is the primary endogenous
Endogenous
Endogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...

 ligand
Ligand (biochemistry)
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. In a narrower sense, it is a signal triggering molecule, binding to a site on a target protein.The binding occurs by intermolecular forces, such as ionic bonds, hydrogen...

 for dopamine receptors.

Dopamine receptors are implicated in many neurological processes, including motivation, pleasure, cognition, memory, learning, and fine motor control, as well as modulation of neuroendocrine signaling. Abnormal dopamine receptor signaling and dopaminergic nerve function is implicated in several neuropsychiatric disorders. Thus, dopamine receptors are common neurologic drug targets; antipsychotics are often dopamine receptor antagonist
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...

s while psychostimulants are typically indirect agonist
Indirect agonist
In pharmacology, an indirect agonist or indirect-acting agonist is a substance that enhances the release or action of an endogenous neurotransmitter but has no specific agonist activity at the neurotransmitter receptor itself...

s of dopamine receptors.

Dopamine receptor subtypes

There are at least five subtypes of dopamine receptors, D1, D2, D3, D4, and D5. The D1 and D5 receptors are members of the D1-like family
D1-like receptor
The D1-like receptors are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D1-like subfamily consists of two G-protein coupled receptors which are coupled to Gs and mediate excitatory neurotransmission, including D1 and D5. For more information, please see...

of dopamine receptors, whereas the D2, D3 and D4 receptors are members of the D2-like family
D2-like receptor
The D2-like receptors are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D2-like subfamily consists of three G-protein coupled receptors which are coupled to Gi/Go and mediate inhibitory neurotransmission, including D2, D3, and D4...

. There is also some evidence that suggests the existence of possible D6 and D7 dopamine receptors, but such receptors have not been conclusively identified.

At a global level, D1 receptors have widespread expression throughout the brain. Furthermore, D1-2 receptor subtypes are found at 10-100 times the levels of the D3-5 subtypes.

D1-like family

Activation of D1-like family receptor
D1-like receptor
The D1-like receptors are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D1-like subfamily consists of two G-protein coupled receptors which are coupled to Gs and mediate excitatory neurotransmission, including D1 and D5. For more information, please see...

s is coupled to the G protein
G protein
G proteins are a family of proteins involved in transmitting chemical signals outside the cell, and causing changes inside the cell. They communicate signals from many hormones, neurotransmitters, and other signaling factors. G protein-coupled receptors are transmembrane receptors...

 Gαs, which subsequently activates adenylate cyclase
Adenylate cyclase
Adenylate cyclase is part of the G protein signalling cascade, which transmits chemical signals from outside the cell across the membrane to the inside of the cell ....

, increasing the intracellular concentration of the second messenger
Second messenger system
Second messengers are molecules that relay signals from receptors on the cell surface to target molecules inside the cell, in the cytoplasm or nucleus. They relay the signals of hormones like epinephrine , growth factors, and others, and cause some kind of change in the activity of the cell...

 cyclic adenosine monophosphate
Cyclic adenosine monophosphate
Cyclic adenosine monophosphate is a second messenger important in many biological processes...

 (cAMP).
  • D1 is encoded by the Dopamine receptor D1
    Dopamine receptor D1
    Dopamine receptor D1, also known as DRD1, is a protein that in humans is encoded by the DRD1 gene.- Function :This gene encodes the D1 subtype of the dopamine receptor. The D1 subtype is the most abundant dopamine receptor in the central nervous system. This G-protein-coupled receptor stimulates...

     gene .

  • D5 is encoded by the Dopamine receptor D5
    Dopamine receptor D5
    D dopamine receptor is a protein that in humans is encoded by the DRD5 gene.This gene encodes the D5 subtype of the dopamine receptor. The D5 subtype is a G-protein coupled receptor which stimulates adenylyl cyclase. This receptor is expressed in neurons in the limbic regions of the brain. It has a...

     gene .

D2-like family

Activation of D2-like family receptor
D2-like receptor
The D2-like receptors are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D2-like subfamily consists of three G-protein coupled receptors which are coupled to Gi/Go and mediate inhibitory neurotransmission, including D2, D3, and D4...

s is coupled to the G protein
G protein
G proteins are a family of proteins involved in transmitting chemical signals outside the cell, and causing changes inside the cell. They communicate signals from many hormones, neurotransmitters, and other signaling factors. G protein-coupled receptors are transmembrane receptors...

 Gαi
Gi alpha subunit
Gi alpha subunit is a heterotrimeric G protein subunit that inhibits the production of cAMP from ATP.- Receptors :The following G protein-coupled receptors couple to the Gi subunit:* Acetylcholine M2 & M4 receptors...

, which directly inhibits the formation of cAMP by inhibiting the enzyme adenylate cyclase.
  • D2 is encoded by the Dopamine receptor D2
    Dopamine receptor D2
    Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the DRD2 gene.- Function :This gene encodes the D2 subtype of the dopamine receptor. This G protein-coupled receptor inhibits adenylyl cyclase activity...

     gene , of which there are two forms: D2Sh (short) and D2Lh (long):
    • The D2Sh form is pre-synaptically situated, having modulatory functions (viz., autoreceptor
      Autoreceptor
      An autoreceptor is a receptor located on presynaptic nerve cell membranes and serves as a part of a feedback loop in signal transduction. It is sensitive only to those neurotransmitters or hormones that are released by the neuron in whose membrane the autoreceptor sits.Canonically, a presynaptic...

      s, which regulate neurotransmission by feed-back mechanisms, affecting synthesis, storage, and release of dopamine
      Dopamine
      Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

       into the synaptic cleft).
    • The D2Lh form may function as a classical post-synaptic receptor, i.e., transmit information (in either an excitatory or an inhibitory fashion) unless blocked by a receptor antagonist
      Receptor antagonist
      A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...

       or a synthetic partial agonist
      Agonist
      An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...

      .

  • D3 is encoded by the Dopamine receptor D3
    Dopamine receptor D3
    D dopamine receptor is a protein that in humans is encoded by the DRD3 gene.This gene encodes the D3 subtype of the dopamine receptor. The D3 subtype inhibits adenylyl cyclase through inhibitory G-proteins. This receptor is expressed in phylogenetically older regions of the brain, suggesting that...

     gene . Maximum expression of dopamine D3 receptors is noted in the islands of Calleja
    Islands of Calleja
    The islands of Calleja are a group of neural granule cells located within the ventral striatum in the brains of most animals. This region of the brain is part of the limbic system, where it aids in the reinforcing effects of reward-like activities...

     and nucleus accumbens
    Nucleus accumbens
    The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...

    .

  • D4 is encoded by the Dopamine receptor D4 gene . The D4 receptor gene displays polymorphisms that differ in a variable number tandem repeat
    Variable number tandem repeat
    A Variable Number Tandem Repeat is a location in a genome where a short nucleotide sequence is organized as a tandem repeat. These can be found on many chromosomes, and often show variations in length between individuals. Each variant acts as an inherited allele, allowing them to be used for...

     present within the coding sequence of exon
    Exon
    An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...

     3. Some of these alleles are associated with greater incidence of certain diseases. For example, the D4.7 alleles have an established association with attention-deficit hyperactivity disorder
    Attention-deficit hyperactivity disorder
    Attention deficit hyperactivity disorder is a developmental disorder. It is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone" and symptoms starting before seven years of age.ADHD is the most commonly studied and...

    .

Role of dopamine receptors in the central nervous system

Dopamine receptors control neural signaling that modulates many important behaviors, such as spatial
Spatial memory
In cognitive psychology and neuroscience, spatial memory is the part of memory responsible for recording information about one's environment and its spatial orientation. For example, a person's spatial memory is required in order to navigate around a familiar city, just as a rat's spatial memory is...

 working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...

. Although dopamine receptors are widely distributed in the brain, different areas have different receptor types densities, presumably reflecting different functional roles.

Cardio-pulmonary system

In humans, the pulmonary artery
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....

 expresses D1, D2, D4, and D5 and receptor subtypes, which may account for vasodilatory effects of dopamine in the blood. In rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...

s, D1-like receptors are present on the smooth muscle
Smooth muscle
Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...

 of the blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...

s in most major organs.

D4 receptors have been identified in the atria of rat and human heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

s. Dopamine increases myocardial contractility and cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...

, without changing heart rate
Heart rate
Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....

, by signaling through dopamine receptors.

Renal system

Dopamine receptors are present along the nephron
Nephron
The renal tubule is the portion of the nephron containing the tubular fluid filtered through the glomerulus. After passing through the renal tubule, the filtrate continues to the collecting duct system, which is not part of the nephron....

 in the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...

, with proximal tubule
Proximal tubule
The proximal tubule is the portion of the duct system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle.-Structure and appearance:...

 epithelial cells showing the highest density. In rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...

s, D1-like receptors are present on the juxtaglomerular apparatus
Juxtaglomerular apparatus
The juxtaglomerular apparatus is a microscopic structure in the kidney, which regulates the function of each nephron. The juxtaglomerular apparatus is named for its proximity to the glomerulus: it is found between the vascular pole of the renal corpuscle and the returning distal convoluted tubule...

 and on renal tubules, while D2-like receptors are present on the renal tubules, glomeruli, postganglionic sympathetic nerve terminals, and zona glomerulosa
Zona glomerulosa
The zona glomerulosa of the adrenal gland is the most superficial layer of the adrenal cortex, lying directly beneath the adrenal gland's capsule...

 cells of the adrenal cortex. Dopamine signaling affects diuresis
Diuresis
Diuresis may refer to:* Urine production, as an aspect of fluid balance* Excessive urine production - see polyuria* Immersion diuresis...

 and natriuresis
Natriuresis
Natriuresis is the process of excretion of sodium in the urine via action of the kidneys. Natriuresis is promoted by Brain and Atrial natriuretic peptides, and it is inhibited by chemicals such as aldosterone...

.

Dopamine receptors in disease

Dysfunction of dopaminergic neurotransmission in the CNS has been implicated in a variety of neuropsychiatric disorders, including social phobia
Social anxiety disorder
Social anxiety disorder , also known as social phobia, is an anxiety disorder characterized by intense fear in social situations causing considerable distress and impaired ability to function in at least some parts of daily life...

, Tourette's syndrome, Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...

, schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

, neuroleptic malignant syndrome
Neuroleptic malignant syndrome
Neuroleptic malignant syndrome is a life- threatening neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs...

, attention-deficit hyperactivity disorder
Attention-deficit hyperactivity disorder
Attention deficit hyperactivity disorder is a developmental disorder. It is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone" and symptoms starting before seven years of age.ADHD is the most commonly studied and...

 (ADHD), and drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

 and alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 dependence
Physical dependence
Physical dependence refers to a state resulting from chronic use of a drug that has produced tolerance and where negative physical symptoms of withdrawal result from abrupt discontinuation or dosage reduction...

.

Attention-deficit hyperactivity disorder

Dopamine receptors have been recognized as important components in the etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

 of ADHD for many years. Drugs used to treat ADHD, including methylphenidate
Methylphenidate
Methylphenidate is a psychostimulant drug approved for treatment of attention-deficit hyperactivity disorder, postural orthostatic tachycardia syndrome and narcolepsy. It may also be prescribed for off-label use in treatment-resistant cases of lethargy, depression, neural insult and obesity...

 and amphetamine
Amphetamine
Amphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...

, have significant effects on dopamine signaling in the brain. Studies of gene association have implicated several genes within dopamine signaling pathways; in particular, the D4.7 variant of D4 has been consistently shown to be more frequent in ADHD patients. ADHD patients with the 4.7 allele also tend to have better cognitive performance and long-term outcomes compared to ADHD patients without the 4.7 allele, suggesting that the allele is associated with a more benign form of ADHD.

The D4.7 allele has suppressed gene expression
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...

 compared to other variants.

Recreational drug use and abuse

Dopamine is the primary neurotransmitter involved in the reward pathways in the brain. Thus, drugs that increase dopamine signaling may produce euphoric effects. Many recreational drugs, such as cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...

 and amphetamine
Amphetamine
Amphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...

s, alter the functionality of the dopamine transporter
Dopamine transporter
The dopamine transporter is a membrane-spanning protein that pumps the neurotransmitter dopamine out of the synapse back into cytosol, from which other transporters sequester DA and NE into vesicles for later storage and release...

 (DAT), the protein responsible for removing dopamine from the neural synapse
Synapse
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell...

. When DAT activity is blocked, the synapse floods with dopamine and increases dopaminergic signaling. When this occurs, particularly in the nucleus accumbens
Nucleus accumbens
The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...

, increased D1 and D2 receptor signaling mediates the "rewarding" stimulus of drug intake. Reward pathway signaling can affect other regions of the brain as well, inducing long-term changes in regions such as the nucleus accumbens and frontal cortex; these changes can strengthen drug craving and alter cognitive pathways, with drug abuse
Drug abuse
Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...

 potentially creating drug addiction and drug dependence.

Schizophrenia

While there is evidence that the dopamine system is involved in schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

, the theory that hyperactive dopaminergic signal transduction
Signal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...

 induces the disease is controversial. Psychostimulants, such as amphetamine and cocaine, induce dramatic changes in dopamine signaling; large doses and prolonged usage can induce symptoms that resemble schizophrenia. Additionally, many antipsychotic
Antipsychotic
An antipsychotic is a tranquilizing psychiatric medication primarily used to manage psychosis , particularly in schizophrenia and bipolar disorder. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s...

 drugs target dopamine receptors, especially D2 receptors.

Genetic hypertension

Dopamine receptor mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

s can cause genetic hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

 in humans. This can occur in animal model
Animal model
An animal model is a living, non-human animal used during the research and investigation of human disease, for the purpose of better understanding the disease without the added risk of causing harm to an actual human being during the process...

s and humans with defective dopamine receptor activity, particularly D1.

Dopamine regulation

Dopamine receptors are typically stable, however sharp (and sometimes prolonged) increases or decreases in dopamine levels (via stimulants or antipsychotics mainly) can downregulate
Downregulation and upregulation
Downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external variable...

 (reduce the numbers of) or upregulate
Downregulation and upregulation
Downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external variable...

 (increase the numbers of) dopamine receptors. With stimulants, downregulation is typically associated with loss of interest in pleasureable activities, shortened attention span, and drug seeking behavior. With antipsychotics, associated upregulation can cause tardive dyskinesia
Tardive dyskinesia
Tardive dyskinesia is a difficult-to-treat form of dyskinesia that can be tardive...

 (fine muscles, like the face, twitch involuntarily), or just plain dyskinesia (same but only temporary).

Haloperidol
Haloperidol
Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines....

, and some other antipsychotics, have been shown to increase the activity of the D2 receptor. Haloperidol induced activity up to 98% higher than baseline in as many as two weeks, but yielded significant dyskinesia side effects. Another study showed in a living subject, dopamine 2 receptors had increased approximately 90% after neuroleptic treatment.

There are differing reports of abused stimulants, and up/down regulation. According to one study, cocaine, heroin, amphetamine, alcohol, and nicotine cause decreases in dopamine 2 receptor quantity. A similar association has been linked to food addiction, with a low availability of dopamine receptors present in people with greater food intake. A recent news article summarized a U.S. DOE
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...

 Brookhaven National Laborotory study showing that increasing dopamine receptors with genetic therapy decreased cocaine consumption up to 75%, but only lasting for six days.

A contrasting study of cocaine shows that cocaine upregulates D3 receptors in the nucleus accumbens
Nucleus accumbens
The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...

, possibly contributing to drug seeking behavior.

Working memory training has been associated with dopamine D1 receptor downregulation, which is believed to have an important role in working memory tasks.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK