TITLE

Dopamine signals for reward value and risk: basic and recent data

AUTHOR(S)
Schultz, Wolfram
PUB. DATE
January 2010
SOURCE
Behavioral & Brain Functions;2010, Vol. 6, p24
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: Previous lesion, electrical self-stimulation and drug addiction studies suggest that the midbrain dopamine systems are parts of the reward system of the brain. This review provides an updated overview about the basic signals of dopamine neurons to environmental stimuli. Methods: The described experiments used standard behavioral and neurophysiological methods to record the activity of single dopamine neurons in awake monkeys during specific behavioral tasks. Results: Dopamine neurons show phasic activations to external stimuli. The signal reflects reward, physical salience, risk and punishment, in descending order of fractions of responding neurons. Expected reward value is a key decision variable for economic choices. The reward response codes reward value, probability and their summed product, expected value. The neurons code reward value as it differs from prediction, thus fulfilling the basic requirement for a bidirectional prediction error teaching signal postulated by learning theory. This response is scaled in units of standard deviation. By contrast, relatively few dopamine neurons show the phasic activation following punishers and conditioned aversive stimuli, suggesting a lack of relationship of the reward response to general attention and arousal. Large proportions of dopamine neurons are also activated by intense, physically salient stimuli. This response is enhanced when the stimuli are novel; it appears to be distinct from the reward value signal. Dopamine neurons show also unspecific activations to non-rewarding stimuli that are possibly due to generalization by similar stimuli and pseudoconditioning by primary rewards. These activations are shorter than reward responses and are often followed by depression of activity. A separate, slower dopamine signal informs about risk, another important decision variable. The prediction error response occurs only with reward; it is scaled by the risk of predicted reward. Conclusions: Neurophysiological studies reveal phasic dopamine signals that transmit information related predominantly but not exclusively to reward. Although not being entirely homogeneous, the dopamine signal is more restricted and stereotyped than neuronal activity in most other brain structures involved in goal directed behavior.
ACCESSION #
51183190

 

Related Articles

  • Accumbal dopamine and cocaine reinstatement. Anderson, Sharon M.; Bari, Ausaf A.; Pierce, R. Christopher // Psychopharmacology;2003, Vol. 168 Issue 1/2, p132 

    .Rationale.. A growing literature indicates that increased dopamine transmission in the nucleus accumbens contributes to priming-induced reinstatement of cocaine-seeking behavior.Objectives.. The present experiments were designed to assess the role of D[sub 1] -like dopamine receptors in the...

  • From the bench to the bedside: Medulloblastoma subtypes, cholinergic neuron function in the nucleus accumbens, and mechanisms of chronic neuropathic pain. Hauptman, Jason S. // Surgical Neurology International;2011, Vol. 2 Issue 1, p68 

    The article presents several medical studies analyzing the several medical phenomena including, various subtypes of medulloblastomas, and the significance of cholinergic neuron in the nucleus accumbens. It is reported that, medulloblastomas tumors are composed of groups of tumors with different...

  • Striatal Pre- and Postsynaptic Profile of Adenosine A2A Receptor Antagonists. Orru, Marco; Bakešová, Jana; Brugarolas, Marc; Quiroz, César; Beaumont, Vahri; Goldberg, Steven R.; Lluís, Carme; Cortés, Antoni; Franco, Rafael; Casadó, Vicent; Canela, Enric I.; Ferré, Sergi // PLoS ONE;2011, Vol. 6 Issue 1, p1 

    Striatal adenosine A2A receptors (A2ARs) are highly expressed in medium spiny neurons (MSNs) of the indirect efferent pathway, where they heteromerize with dopamine D2 receptors (D2Rs). A2ARs are also localized presynaptically in corticostriatal glutamatergic terminals contacting MSNs of the...

  • Early effect of NEURAPAS balance on current source density (CSD) of human EEG.  // BMC Psychiatry;2011, Vol. 11 Issue 1, p123 

    The article discusses a study by Wilfried Dimpfel and colleagues conducted to examine the effect of the drug NEURAPAS balance on the current source density (CSD) of electroencephalogram (EEG) in psychiatric patients who suffer from stress, anxiety and depression. The analysis of the...

  • Attenuation of relapse to cocaine seeking by dopamine D[sub 1] receptor agonists and antagonists in non-human primates. Khroyan, Taline V.; Platt, Donna M.; Rowlett, James K.; Spealman, Roger D. // Psychopharmacology;2003, Vol. 168 Issue 1/2, p124 

    .Rationale. Dopamine D[sub 1] receptor agonists and antagonists attenuate reinstatement of cocaine seeking in a non-human primate model of relapse. The mechanisms by which these different classes of D[sub 1] receptor drugs produce these similar effects on cocaine seeking are unknown.Objectives....

  • Opiate versus psychostimulant addiction: the differences do matter. Badiani, Aldo; Belin, David; Epstein, David; Calu, Donna; Shaham, Yavin // Nature Reviews Neuroscience;Nov2011, Vol. 12 Issue 11, p685 

    The publication of the psychomotor stimulant theory of addiction in 1987 and the finding that addictive drugs increase dopamine concentrations in the rat mesolimbic system in 1988 have led to a predominance of psychobiological theories that consider addiction to opiates and addiction to...

  • Levo-tetrahydropalmatine attenuates cocaine self-administration and cocaine-induced reinstatement in rats. Mantsch, John R.; Shi-Jiang Li; Risinger, Robert; Awad, Sarah; Katz, Eric; Baker, David A.; Zheng Yang // Psychopharmacology;Jul2007, Vol. 192 Issue 4, p581 

    Levo-tetrahydropalmatine ( l-THP) is an alkaloid constituent of plants from the botanical genera Corydalis and Stephania and is contained in many traditional Chinese herbal preparations. In addition to its low-affinity antagonism of D2 dopamine (DA) receptors, we report that l-THP functions as a...

  • Individual differences in cocaine-induced locomotor activity in male Sprague–Dawley rats and their acquisition of and motivation to self-administer cocaine. Mandt, Bruce; Schenk, Susan; Zahniser, Nancy; Allen, Richard // Psychopharmacology;Dec2008, Vol. 201 Issue 2, p195 

    Factors that increase an individual’s susceptibility to cocaine dependence remain largely unknown. We have previously shown that adult outbred male Sprague–Dawley rats can be classified as either low or high cocaine responders (LCRs or HCRs, respectively) based on their locomotor...

  • Premature poking: impulsivity, cocaine and dopamine. Uhl, George // Nature Medicine;Apr2007, Vol. 13 Issue 4, p413 

    The article discusses an experimental system which links impulsivity, dopamine and addiction in rats. The approach suggests that rats chosen for impulsivity also self-administer large amounts of cocaine. The rats have fewer available dopamine receptors in the ventral striatum. The approach is...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics