Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Reward”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources
PubMed2000

Cannabinoid receptors and reward in the rat: a conditioned place preference study.

RATIONALE: We wished to investigate further the hypothesis of an endogenous cannabinoid 'aversive counter-rewarding system, as the rewarding properties of cannabinoids using standard procedures remain ambiguous. OBJECTIVES: The purpose of this study was to confirm the behavioural effects of a highly potent synthetic cannabinoid agonist (HU210) and the selective cannabinoid antagonist SR 141716A using conditioned place preference (CPP). METHODS: HU210 (20, 60 and 100 microg kg(-1), SR141716A (0.25, 0.5, 2 and 3 mg kg(-1)), cocaine (15 mg kg(-1) and delta9-THC (1.5 mg kg(-1)) were given to male Lister hooded rats using an unbiased CPP design. RESULTS: SR141716A and cocaine produced place preference at all doses tested, whereas HU210 and delta9-THC produced aversion as expressed by time spent in the drug-paired compartment of the CPP apparatus. CONCLUSIONS: The aversive effects of cannabinoid agonists and the rewarding effect of the cannabinoid antagonist are suggestive of a cannabinergic tone in the rat brain. Further research is needed to determine the precise relationship of that tone with the reward pathways of the brain.

Animals↗
PubMed2000

Effects of repeated withdrawal from continuous amphetamine administration on brain reward function in rats.

RATIONALE: The study of the effects of repeated amphetamine administration and withdrawal on brain reward function has relevance to both amphetamine dependence and non-drug-induced depressions. OBJECTIVES: The purpose of this study was to investigate the effects of continuous amphetamine administration and withdrawal on brain stimulation reward thresholds, and the changes that occur with repeated amphetamine exposures. METHODS: Rats were prepared with bipolar electrodes in the lateral hypothalamus and trained in a discrete-trial reward threshold procedure. Then, rats underwent two separate periods of amphetamine administration via subcutaneous osmotic mini-pumps. RESULTS: Continuous amphetamine administration was associated with lowering in brain reward thresholds and decreases in response latencies, while withdrawal was associated with threshold elevations. These effects changed with subsequent amphetamine administration and withdrawal. CONCLUSIONS: The results of this study indicated that with the amphetamine administration regime used here, rats developed increased sensitivity to the effects of acute amphetamine administration and tolerance to the effects of amphetamine withdrawal.

Amphetamine↗
PubMed1997

Gamma-vinyl GABA attenuates cocaine-induced lowering of brain stimulation reward thresholds.

Gamma-vinyl GABA (GVG, also referred to as vigabatrin), an irreversible inhibitor of GABA transaminase (GABA-T), raises levels of GABA in nerve terminals, inhibits striatal dopamine release, and attenuates cocaine-induced increases in extracellular dopamine in the striatum and nucleus accumbens. In order to determine the action of GVG on dopamine-mediated reward, we examined its effects on the threshold for rewarding brain stimulation in male F-344 rats. GVG dose-dependently raised brain stimulation reward (BSR) thresholds at doses of 200, 300, and 400 mg/kg without significant effects on motor performance as measured by response latencies. In order to determine if GVG had similar modulatory effects on cocaine-induced lowering of BSR thresholds, the effective doses of GVG were co-administered with 2.5 and 5.0 mg/kg cocaine, doses that significantly lower BSR thresholds. The 400 mg/kg dose of GVG significantly blocked the lowering of thresholds seen at each dose of cocaine. Cocaine in combination with 200 or 300 mg/kg GVG, doses of GVG that significantly raise BSR thresholds, resulted in thresholds not significantly different from those obtained with cocaine alone. These data demonstrate that, at the doses tested, GVG is more effective at modulating basal reward thresholds that at modulating thresholds lowered by cocaine, implying that as dopaminergic activity increases, GABAergic activity must also increase in order to exert its inhibitory influence on dopaminergic activity.

4-Aminobutyrate Transaminase↗
PubMed2007

Functional differences between macaque prefrontal cortex and caudate nucleus during eye movements with and without reward.

The prefrontal cortex and the basal ganglia form mutually connected networks and are thought to play essential roles together in guiding goal-directed behaviors. Yet, these structures seem to have independent pathways to motor outputs as well, suggesting differential contributions to goal-directed behaviors. We hypothesized that the prefrontal cortex guides actions to a direction required by external demands and the basal ganglia guide actions to an internally motivated direction. To test this hypothesis, we used a task in which monkeys were required to make a memory-guided saccade to a direction indicated by a visual cue while only one direction was associated with reward. We observed a functional dissociation between the lateral prefrontal cortex (LPFC), which commonly represented the cue direction, and the caudate nucleus (CD), which commonly represented the reward-associated direction. Furthermore, cue-directed and reward-directed signals were integrated differently in the two areas; when the cue direction and the reward direction were opposite, LPFC neurons maintained tuning to the cue direction, whereas CD neurons lost the tuning. Different types of spatial tuning in the two brain areas may contribute to different types of goal-directed behavior.

Analysis of Variance↗
PubMed2004

Effort-reward imbalance and physical health among Japanese workers in a recently downsized corporation.

OBJECTIVES: The present study investigated the effort-reward imbalance (ERI) model-related biological markers of disease risks in Japanese workers of a recently downsized manufacturing corporation. METHODS: A total of 441 workers was examined to find whether situational effort-reward imbalance or personal overcommitment was associated with hematological and biochemical measurements, serum cortisol, and urine biopyrrins as oxidative metabolites of antioxidant bilirubin. RESULTS: The effort-reward imbalance was positively associated with the values of red blood cells, hemoglobin, hematocrit, triglycerides and glutamic pyruvic transaminase (GPT), and negatively correlated with the high-density lipoprotein cholesterol level. Overcommitment was positively related to the values of hematocrit and glucose levels, but negatively associated with the total protein level. The relationships between effort-reward imbalance and GPT level, and that between overcommitment and glucose level, persisted when potential confounders were adjusted for. The ERI model was not significantly related to either cortisol or biopyrrins levels. CONCLUSIONS: The ERI model seems to have an impact on the physical health of the downsized Japanese workers, although the results are mixed and are different from those in workers of Western countries.

Adult↗
PubMed2004

Response perseveration and sensitivity to reward and punishment in boys with oppositional defiant disorder.

Response perseveration is the tendency to continue a response set for reward despite punishment. In the present study, response perseveration and sensitivity to reward and punishment were assessed in boys with oppositional defiant disorder (ODD). The study also examined the relation between punishment sensitivity and autonomic arousal. Nineteen ODD boys (mean age 9.8 years) and 20 normal control boys (NC) (mean age 9.7 years) were administered the door-opening task. In this task, the subject chooses either to open the next door or to stop playing; the opening of doors is initially rewarded and then increasingly punished. ODD boys opened more doors than NC boys. Following punishment, ODD boys took less time than NC boys before opening the next door, but did not differ from NC boys in time after reward. Mean skin conductance level was lower in ODD boys than in NC boys. The correlation coefficient between time after punishment and skin conductance level was moderately positive in the total sample. These results suggest that response perseveration in ODD boys is related to low punishment sensitivity and that skin conductance level is a marker of punishment sensitivity.

Arousal↗
PubMed1978

Electrical activation of visual pathways substitutes for tonic light input in triggering EEG correlates of food reward during conditioned behavior in cats.

Cats trained to press a lever for 1 cc of milk reward normally show during the consummatory response high voltage 6--8 c/sec EEG synchronization associated with epicortical positive steady potential shift over the primary and secondary visual projections. The emergence of this postreinforcement synchronization (PRS) and Reward Contingent Positive Variation (RCPV) is known to depend upon appropriate gustatory input and presence of ambient light, although visual perception of reward and/or environment is not essential as shown in cats wearing translucent "milky" contact lenses. Training the animals in a paradigm in which a "light-off" cue signaled the availability of reward, and thus assigned positively reinforcing quality to the dark condition, also failed to restore the PRS-RCPV phenomenon in the absence of light. However, brief electrical stimuli applied to either the optic tract or the lateral geniculate nucleus substituted for unpatterned light input and fully restored the PRS-RCPV in the dark. The suprathreshold stimuli were effective only during the consummatory response. Maximum effect could be produced during a brief time period between 0.8 and 1.5 sec after the onset of consummatory response as judged by lapping activity, thus showing the specificity of the effect of visual input. Even during a relaxed wakefulness after satiation or during slow wave sleep or REM sleep the same electric stimuli were ineffective although they produced well-developed evoked potentials with all characteristic wave components. The results indicate that brain pathways utilize unpatterned i.e. noisy visual input in complex integrative processes involving gustatory input.

Animals↗
PubMed1979

Conditioned aversion to brain-stimulation reward: effects of electrode placement and prior experience.

A conditioned aversion to rewarding amygdaloid brain-stimulation was established by injecting rats with toxic doses of 0.15 M LiCl immediately after an initial self-stimulation session. The aversion had extinguished by the third self-stimulation session, 96 h after conditioning. This effect cannot be attributed to general depressant effects of LiCl on self-stimulation as treatment with LiCl 24 h before the second self-stimulation session was ineffective. Furthermore, this conditioned aversion was locus specific as LiCl injections immediately after the first test session had no disruptive effects on self-stimulation in the substantia nigra. The parallels between conditioned aversion to rewarding brain-stimulation in the amygdala and late aversion were strengthened by the fact that the novelty of brain-stimulation reward was an important factor in the conditioning effect. These data have important implications for understanding the sensory properties of brain-stimulation reward.

Amygdala↗
PubMed1984

Hippocampus modulates self-stimulation reward from the ventral tegmental area in the rat.

Rats with electrodes in the ventral tegmental area were tested for the threshold of intracranial reward using a rate insensitive self-stimulation procedure. It was found that an electrolytic lesion of a part of the dorsal hippocampus induced a marked decrease in the variation of thresholds across rats, while the mean reward level did not change. This indicates that a factor is removed, by the hippocampal lesion, which causes differences in reward between individual rats. It is suggested that the mesolimbic dopaminergic system is involved in this modulatory influence of the hippocampus on reward.

Animals↗
PubMed1985

Reward related neuronal activity in monkey dorsolateral prefrontal cortex during feeding behavior.

Extracellular single neuron activity was recorded in the dorsolateral prefrontal cortex (DL) during bar pressing for food reward. Most of the reward-related neurons were located around the rostral end of the principal sulcus. Neuronal activity was diminished, abolished, or reversed when quinine adulterated food (aversive food) was given as a reinforcement. Cue-related neurons tended to be located more caudally in the DL. The activity of these neurons was not modulated by the nature of the reward as much as that of the reward-related neurons. The results suggest that DL neurons are not functionally homogeneous.

Animals↗
PubMed1986

Opiate mechanism in reward-related neuronal responses during operant feeding behavior of the monkey.

Reward-related neuronal activity and its modulation by morphine and naloxone was investigated by extracellular single neuron recording and electrophoretic application of drugs in the lateral hypothalamus, during operant feeding of the monkey. Morphine-sensitive neurons responded more often during bar press and ingestion-reward phases. Naloxone blocked only ingestion-reward responses, especially the inhibitory ones. The results suggest that the central opiate system can be involved in reward-related neuronal responses in the lateral hypothalamic area of the monkey.

Animals↗
PubMed1989

Regional neuroleptic microinjections indicate a role for nucleus accumbens in lateral hypothalamic self-stimulation reward.

Bilateral microinjections of the neuroleptic, cis-flupenthixol, were made into 56 forebrain targets distributed across various dopamine (DA) terminal fields in the forebrain. Drug effects on medial forebrain bundle (MFB) stimulation-produced reward were assessed with a rate-frequency procedure implemented in a runway paradigm in a discrete-trial fashion. This method generated independent measures of drug-induced changes in the MFB stimulation reward and operant motor/performance capacity. Control experiments were run with the inactive isomer, trans-flupenthixol. Results indicate a major role for accumbens DA in MFB reward, but not for the DA in caudate and medial frontal cortex. Few drug-induced motor/performance deficits were found at any site. In 14 selected subjects, 6-OHDA-induced chronic DA lesions were made at the same site as neuroleptic microinjection. These results confirmed the reward effects of acute DA receptor blockade, but produced a greater associated motor/performance impairment. Both behavioral effects of the lesion recovered within 2 weeks in many, but not all subjects.

Animals↗
PubMed1992

Opiate infusion into nucleus accumbens: contrasting effects on motor activity and responding for conditioned reward.

In the present experiments, we examined the roles of opiate receptor subtypes in the nucleus accumbens in spontaneous motor behavior and responding for conditioned reward. Locomotor activity was measured using photocell cages and reward-related responding was determined in the conditioned reinforcement (CR) paradigm. In the CR paradigm, food-deprived rats were trained to associate a compound stimulus with food reward, and were subsequently tested for responding on a lever that resulted in presentation of the compound stimulus alone. In all experiments, various opiate agonists were microinjected into the nucleus accumbens. In the activity studies, morphine sulfate (mixed mu and delta agonist; 0.025, 0.25 and 2.5 micrograms/0.5 microliter) caused an initial inhibition followed by a disinhibition of activity while [D-Ala2-Met5]-enkephalin (DALA) (mixed mu and delta agonist; 0.25, 2.5 and 5.0 micrograms/0.5 microliter) elicited an immediate potentiation of locomotor activity. The behavioral profile following [D-Ala2-N-Me-Phe4-Gly-ol5]-enkephalin (DAMGO; mu agonist; 0.01, 0.1 and 1.0 micrograms/0.5 microliter) was similar to morphine. In contrast, [D-Pen2,5]-enkephalin (DPEN; delta agonist; 0.02, 0.2 and 2.0 micrograms/0.5 microliter) induced an immediate, but relatively short-lasting activation. Both DALA and DPEN also dose-dependently enhanced rearing; rearing was not affected by the other treatments. U50,488H (kappa agonist; 0.0186, 0.186 and 1.86 micrograms/0.5 microliter) had no effect on any aspect of motor activity. In contrast to effects on motor activity, none of the opiate agonists significantly potentiated responding for CR, although morphine infusion did tend to increase responding somewhat. In contrast, D-amphetamine (20 micrograms/0.5 microliter) did potentiate responding, as previously reported. A distinction between the effects of opiates and psychostimulants on reinforced responding is hypothesized based on differential modulation of dopamine release. These experiments demonstrate a dissociation of the effects of opiates on locomotor activity and reward-related responding.

Animals↗
PubMed1995

The bidirectional interaction between ventral tegmental rewarding and hindbrain aversive stimulation effects in the rat.

We used the curve-shift procedure in self-stimulating rats to examine the interaction of aversive and rewarding electrical stimuli in terms of duration and direction. The subjects were implanted with two moveable electrodes, one in a region supporting self-stimulation (the ventral tegmental area, VTA) and another in a region supporting escape (the nucleus reticularis gigantocellularis, Gi). The function relating self-stimulation rate to pulse frequency (RF function) was first obtained and then replicated in a condition where each VTA pulse was followed 0.2 or 2.0 ms later by a Gi pulse. The intensity of Gi pulses was set at a value previously found to elicit escape within less than 5 sec. The following observations were made: (1) rats self-stimulated consistently, despite the presence of Gi pulses, (2) the presence of Gi pulses shifted the RF function rightward (decreased the rewarding efficacy of VTA stimulation), with little effect on the maximum rate, (3) after 2 to 5 VTA-Gi self-stimulation sessions, the Gi pulses progressively lost their ability to shift the RF function, and (4) at the end of testing, escape was no longer detectable using Gi pulses alone. It was concluded that (1) the interaction between rewarding VTA and aversive Gi stimulation effects is bidirectional, thus suggesting the presence of algebraic summation; (2) the effect of Gi on VTA reward is transient whereas that of VTA on Gi aversion cumulates and eventually results in total abolition of Gi aversion. The present study represents the first account of cumulative and long-lasting suppression of aversion following brain stimulation in the rat.

Animals↗
PubMed1992

Anterior brain electrical asymmetries in response to reward and punishment.

A variety of recent research indicates that when subjects are induced to experience certain negative emotions, there is greater suppression of alpha power in the right than left frontal region, while during the experience of positive emotion, alpha power asymmetry in this region shows the opposite pattern. We have conceptualized this asymmetry as reflecting specialization for approach and withdrawal processes in the left and right frontal regions, respectively. In this experiment, reward and punishment contingencies were directly manipulated to produce approach and withdrawal emotional states. In addition, subjects responded to imperative stimuli using either an approach response (finger press) or a withdrawal response (finger lift). EEG was recorded from multiple scalp locations. During the foreperiod prior to the response to the imperative stimuli, the EEG was extracted, Fourier-transformed and power computed in the theta, alpha and beta frequency bands. In addition, the contingent negative variation (CNV) was derived from the identical epoch. Reward trials were associated with greater left frontal alpha power suppression than punishment trials, while during the latter trials, there was greater right-sided frontal alpha power suppression than during reward trials. There was also some evidence to indicate that withdrawal responses were associated with greater right-sided alpha power suppression in the temporo-parietal region compared with approach responses. Power in the theta and beta bands did not systematically vary with condition. The CNV was larger during trials on which subjects responded quickly compared with slow trials, but did not differentiate between reward and punishment contingencies. The findings support the hypothesis that approach-related processes can be differentiated from withdrawal-related processes on the basis of asymmetrical shifts in alpha power in the frontal region. They also indicate that the CNV and spectral power estimates from the identical epochs reflect different neural processes.

Adolescent↗
PubMed1987

The dopamine hypothesis of opiate reward challenged.

The dopamine hypothesis of opiate reward was directly tested by blocking dopamine receptor systems with haloperidol. Haloperidol was administered either systemically or locally into different brain areas with dopaminergic terminals in rats allowed to initiate and maintain intravenous heroin self-administration. Haloperidol treatment did not block heroin reward. It is concluded that dopamine is not critically involved in opiate reward and that multiple endogenous reward systems are present in the brain.

Animals↗
PubMed1995

Conditioned place preference induced by delta 9-tetrahydrocannabinol: comparison with cocaine, morphine, and food reward.

The rewarding property of delta 9-tetrahydrocannabinol (THC), the psychoactive constituent of marijuana and hashish, was studied using the conditioned place preference paradigm, and compared to that of cocaine, morphine, and food reward. The results of Experiment 1 demonstrated that 2.0 and 4.0 mg/kg doses produced a reliable shift in preference for the THC-paired compartment. The THC place preference observed at 2.0 and 4.0 mg/kg was nearly equivalent to that produced by low doses of cocaine (5.0 mg/kg), morphine (4.0 mg/kg), and food in non food-deprived animals. The second experiment used a different conditioning procedure that included a washout period for THC. The results of Experiment 2 demonstrated that a THC place preference could be obtained using a lower dose of THC (1.0 mg/kg), and that this THC place preference was equivalent to that produced by 10 mg/kg cocaine. At higher doses (2.0 and 4.0 mg/kg), THC produced a dose-dependent place aversion. These results suggest that THC's action on brain reward substrates, previously demonstrated by electrical brain stimulation reward, in vivo brain microdialysis, and in vivo brain electrochemistry studies, reflects itself behaviorally in increased appetitive motivational value for environmental stimuli associated with ingestion of marijuana and hashish.

Animals↗
PubMed1987

Reward saturation in medial forebrain bundle self-stimulation.

A rate-frequency curve in self-stimulation experiments plots the response rate as a function of the frequency of stimulation pulses, yielding a steeply rising, roughly sigmoidal curve. Altering stimulation reward efficacy results in lateral shifts of this curve, while altering the operant performance capacity of the rat results in primarily vertical shifts. One hypothesis explaining the lateral stability of the curve in the face of performance-altering manipulations is that the stimulation reward effect saturates at the frequency where the curve asymptotes. In the first experiment we determined the frequency of rate-frequency curve asymptote in two paradigms, runway and lever-pressing, and compared it to the reward saturation frequency determined in a discrete choice procedure. Results indicate that reward often saturates at frequencies above the rate-frequency asymptote point, which does not support the above hypothesis; levelling-off of the rate-frequency function is most likely a result of performance ceiling factors. In a second experiment, increases in stimulation current reduced the saturation frequency, indicating that saturation is not determined by an upper limit on the signal carrying capacity of the directly excited axons.

Action Potentials↗