Search results for "Reward"

Lorcaserin bidirectionally regulates dopaminergic function site-dependently and disrupts dopamine brain area correlations in rats

2020

Abstract Lorcaserin, which is a selective agonist of serotonin2C receptors (5-HT2CRs), is a new FDA-approved anti-obesity drug that has also shown therapeutic promise in other brain disorders, such as addiction and epilepsy. The modulation of dopaminergic function might be critical in the therapeutic effect of lorcaserin, but its exact effect is unknown. Here, we studied the effect of the peripheral administration of lorcaserin on the ventral tegmental area (VTA), the substantia nigra pars compacta (SNc) dopaminergic neural activity, dopamine (DA) dialysis levels in the nucleus accumbens and striatum and on DA tissue levels in 29 different rat brain regions. Lorcaserin (5–640 μg/kg, i.v.) m…

Indomethacin blocks the increased conditioned rewarding effects of cocaine induced by repeated social defeat

2018

It is well established that repeated social defeat stress can induce negative long-term consequences such as increased anxiety-like behavior and enhances the reinforcing effect of psychostimulants in rodents. In the current study, we evaluated how the immune system may play a role in these long-term effects of stress. A total of 148 OF1 mice were divided into different experimental groups according to stress condition (exploration or social defeat) and pre-treatment (saline, 5 or 10 mg/kg of the anti-inflammatory indomethacin) before each social defeat or exploration episode. Three weeks after the last social defeat, anxiety was evaluated using an elevated plus maze paradigm. After this tes…

Centrifugal projections to the main olfactory bulb revealed by trans‐synaptic retrograde tracing in mice

2020

A wide range of evidence indicates that olfactory perception is strongly involved in food intake. However, the polysynaptic circuitry linking the brain areas involved in feeding behavior to the olfactory regions is not well known. The aim of this article was to examine such circuits. Thus, we described, using hodological tools such as transsynaptic viruses (PRV152) transported in a retrograde manner, the long-distance indirect projections (two to three synapses) onto the main olfactory bulb (MOB). The ß-subunit of the cholera toxin which is a monosynaptic retrograde tracer was used as a control to be able to differentiate between direct and indirect projections. Our tracing experiments show…

Social defeat stress: mechanisms underlying the increase in rewarding effects of drugs of abuse

2018

Social interaction is known to be the main source of stress in human beings, which explains the translational importance of this research in animals. Evidence reported over the last decade has revealed that, when exposed to social defeat experiences (brief episodes of social confrontations during adolescence and adulthood), the rodent brain undergoes remodeling and functional modifications, which in turn lead to an increase in the rewarding and reinstating effects of different drugs of abuse. The mechanisms by which social stress cause changes in the brain and behavior are unknown, and so the objective of this review is to contemplate how social defeat stress induces longlasting consequence…

Neurons in the pigeon caudolateral nidopallium differentiate Pavlovian conditioned stimuli but not their associated reward value in a sign-tracking p…

2016

AbstractAnimals exploit visual information to identify objects, form stimulus-reward associations, and prepare appropriate behavioral responses. The nidopallium caudolaterale (NCL), an associative region of the avian endbrain, contains neurons exhibiting prominent response modulation during presentation of reward-predicting visual stimuli, but it is unclear whether neural activity represents valuation signals, stimulus properties, or sensorimotor contingencies. To test the hypothesis that NCL neurons represent stimulus value, we subjected pigeons to a Pavlovian sign-tracking paradigm in which visual cues predicted rewards differing in magnitude (large vs. small) and delay to presentation (s…

Pain-induced alterations in the dynorphinergic system within the mesocorticolimbic pathway: Implication for alcohol addiction.

2020

Latest studies have revealed that pain negatively impacts on reward processing and motivation leading to negative affective states and stress. These states not only reduce quality of life of patients by increasing the appearance of psychiatric comorbidities, but also have an important impact on vulnerability to drug abuse, including alcohol. In fact, clinical, epidemiological but also preclinical studies have revealed that the presence of pain is closely related to alcohol use disorders (AUDs). All this evidence suggests that pain is a factor that increases the risk of suffering AUD, predicting heavy drinking behavior and relapse drinking in those patients with a previous history of AUD. Th…

2017

Perinatal maternal consumption of energy dense food increases the risk of obesity in children. This is associated with an overconsumption of palatable food that is consumed for its hedonic property. The underlying mechanism that links perinatal maternal diet and offspring preference for fat is still poorly understood. In the present study we aim at studying the influence of maternal high-fat/ high-sugar diet feeding (western-diet, WD) during gestation and lactation on the reward pathways controlling feeding in the rat offspring from birth to sexual maturity. We performed a longitudinal follow-up of WD and Control offspring at three critical time periods (childhood, adolescence and adulthood…

Glutamate and opioid antagonists modulate dopamine levels evoked by innately attractive male chemosignals in the nucleus accumbens of female rats

2017

Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in the attraction toward sexual chemosignals. Our data show that female rats with no previous experience with males or their chemosignals display an innate preference for male-soiled bedding. Focal administration of the opioid antagonist b-funaltrexamine into the posterior ventral tegmental area does no…

Le goût sucré, de l’enfance… à la dépendance ?

2013

Summary: Can one talk about addiction to sugar? Sugar is an important part of our diet, and an important source of pleasure, as of a young age. The definition of addiction involves that addictive substances act on the reward circuit, and lead to two symptoms, withdrawal and tolerance. Is it the case with sugar? According to the literature, brain activations in regions involved in the reward circuit are observed in response to “sugar”, and they differ according to the type of sugar (caloric carbohydrates, sweet or not; sweeteners). Besides, withdrawal and tolerance symptoms are not well characterized: food cravings often concern sweet foods, but there is a decrease with age of the preference…

Premis, càstigs i educació

2008

Els autors defensen que el costum i la llei confi guren la legalitat i la moralitat socials i determinen el nostre comportament, alhora que qüestionen els resultats 'esperats' de l'aplicació mecànica dels premis i càstigs en educació. Distingeixen el control extern 'supervisió' i l'intern 'motivació' en l'esdevenir dels comportaments analitzats, en relació a l'aplicació d'aquelles sancions i tot seguit aborden l'estudi monogràfi c des del conductisme, des del cognitivisme i des de la perspectiva moral. Ara aborden la complexitat contextual de la intervenció pedagògica i les alternatives possibles des dels plantejaments actitudinals dels subjectes, per concloure que els premis tenen la fi na…