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1.
Artigo em Inglês | MEDLINE | ID: mdl-36191805

RESUMO

Dopamine is a modulating factor in effort-based decision-making, and emerging evidence from pharmacological research suggests that the dopamine D1 receptor is the primary regulator. Given the limited selectivity of pharmacological tools, we further explored this hypothesis using dopamine D1 mutant (DAD1-/-) rats which have a specific genetic reduction in functional D1 receptors. Moreover, given the strong focus on males in neuroscience research in general and in the role of D1 receptors in effort-based learning, we compared both sexes in the present study. Adult male and female DAD1-/- mutant rats and wild type controls were trained to press a lever for a reinforcer. Once trained, subjects completed multiple fixed ratio, progressive ratio, and operant effort-choice (concurrent progressive ratio/chow feeding task [PROG/chow]) experiments. We predicted that DAD1-/- mutant rats would press the lever significantly less than controls across all experiments, have lower breakpoints, and consume more freely available food. As predicted, DAD1-/- mutant rats (regardless of sex) pressed the lever significantly less than controls and had lower breakpoints. Interestingly, there was a sex * genotype interaction for acquisition rates of lever pressing and change in breakpoints with free food available. Only 31% of DAD1-/- mutant males acquired lever pressing while 73% of DAD1-/- mutant females acquired lever pressing. Additionally, DAD1-/- mutant males had significantly larger decreases in breakpoints when free food was available. These findings extend the pharmacological research suggesting that the dopamine D1 receptor modulates decisions based on effort, which has implications for the development of treatment targeting amotivation in neuropsychiatric disorders. The sex * genotype interaction highlights the importance of including both sexes in future research, especially when there are sex differences in incidences and severity of neuropsychiatric disorders.


Assuntos
Antagonistas de Dopamina , Receptores de Dopamina D1 , Animais , Feminino , Masculino , Ratos , Condicionamento Operante , Tomada de Decisões , Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Ratos Sprague-Dawley , Receptores de Dopamina D1/genética , Caracteres Sexuais
2.
Artigo em Inglês | MEDLINE | ID: mdl-35988849

RESUMO

One of the main obstacles in treating psychostimulant addiction is relapse even after long-term abstinence. The nucleus accumbens (NAc) is located in the basal forebrain, responsible for regulating several behaviors, specifically reward-related effect of psychostimulants. In the current study, an unbiased place conditioning paradigm was performed to inquire the role of the hypocretin/orexin system in the NAc in the extinction and reinstatement of methamphetamine (Meth)-induced conditioned place preference (CPP). Similar to previous investigations, rats were conditioned with Meth (1 mg/kg; sc) for five consecutive days to elicit CPP. The rats underwent Meth conditioning protocol received SB334867 or TCS OX2 29, an orexin receptor 1 (OXr1) antagonist or orexin receptor 2 (OXr2) antagonist (0, 3, 10, and 30 nmol/0.5 µL DMSO %12) in the NAc during the extinction period to elucidate the role of OXrs on the extinction of Meth-induced CPP. Meanwhile, extinguished rats received SB334867 or TCS OX2 29 (0, 1, 3, 10, and 30 nmol/0.5 µL DMSO %12) in the NAc prior to an effective priming dose of Meth to evaluate the impact of OXr antagonists on the reinstatement of Meth-induced CPP. The current data pointed out intra-NAc microinjection of SB334867 or TCS OX2 29 blocked both extinction and reinstatement of Meth-induced CPP. In addition, the OXr1 antagonist was more potent than the OXr2 antagonist to suppress both extinction and reinstatement phases of Meth-induced CPP. Based on the current data, the OX system in the NAc is extensively implicated in the reward properties of Meth; therefore, modulation of this system has therapeutic potential in treating psychostimulant use disorders.


Assuntos
Estimulantes do Sistema Nervoso Central , Metanfetamina , Ratos , Animais , Núcleo Accumbens/metabolismo , Metanfetamina/farmacologia , Orexinas , Receptores de Orexina/metabolismo , Condicionamento Operante , Extinção Psicológica , Dimetil Sulfóxido/farmacologia , Ratos Wistar , Antagonistas dos Receptores de Orexina/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia
4.
Sci Rep ; 12(1): 19683, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36385347

RESUMO

Progressive ratio (PR) schedules of drug delivery are used to determine the 'motivational' state of an animal and drug 'reinforcing efficacy'. This widely held interpretation is supported mainly by the observation that the PR breakpoint (BP) is proportional to the unit dose of self-administered drug. The compulsion zone theory of cocaine self-administration was applied to determine whether it can explain the pattern of lever-pressing behavior and cocaine injections under the PR schedule in rats. This theory states that cocaine induces lever pressing when levels are below the satiety threshold and above the priming/remission threshold. Rats were trained to self-administer cocaine on a fixed ratio FR1 schedule over a range of cocaine unit doses. Then they were switched to a PR schedule. Typical for the self-administration under a PR schedule, long post-injection pauses occurred when calculated cocaine levels were in the satiety zone. The compulsion zone theory interprets BP simply as the maximal number of responses which rats can perform after an injection while cocaine levels remain within the compulsion zone. The thresholds delineating the compulsion zone were very stable and independent of the self-administration schedule. PR and fixed ratio schedules convey the same pharmacokinetic/pharmacodynamic information, i.e., these two schedules are invariant.


Assuntos
Cocaína , Ratos , Animais , Cocaína/farmacologia , Esquema de Reforço , Condicionamento Operante , Ratos Sprague-Dawley , Autoadministração
5.
Addict Biol ; 27(6): e13235, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36301214

RESUMO

When facing a choice, most animals quit drugs in favour of a variety of nondrug alternatives. We recently found, rather unexpectedly, that choice of the nondrug alternative is in fact inflexible and habitual. One possible contributing factor to habitual choice is the intermittency and uncontrollability of choice trials in previous studies. Here, we asked whether and to what extent volitional control over the occurrence of choice trials could change animals' preference by preventing habitual choice. To do so, rats were trained to nosepoke in a hole to trigger the presentation of two operant levers: one associated with cocaine, the other with saccharin. Rats were then free to choose among the two levers to obtain the corresponding reward, after which both levers retracted until rats self-initiated the next choice trial. Overall, we found that volitional control over choice trials did not change preference. Most rats preferred saccharin over cocaine and selected this option almost exclusively. Intriguingly, after repeated choice and consumption of saccharin, rats transiently lost interest in this option (i.e., due to sensory-specific satiety), but they did not switch to cocaine, preferring instead to pause during long periods of time before reinitiating a choice trial for saccharin. This finding suggests that during volitional initiation of a choice trial, rats fail to consider cocaine as an option. We discuss a possible associative mechanism to explain this perplexing behaviour.


Assuntos
Cocaína , Animais , Ratos , Comportamento de Escolha , Cocaína/farmacologia , Condicionamento Operante , Sacarina , Autoadministração
6.
J Exp Psychol Anim Learn Cogn ; 48(4): 396-412, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36265026

RESUMO

The present article explored the fate of previously formed response-outcome associations when the relation between R and O was disrupted by arranging for O to occur independently of R. In each of three experiments response independent outcome delivery selectively reduced the R earning that O. Nevertheless, in Experiments 1 and 2, the R continued to show sensitivity to outcome devaluation, suggesting that the strength of the R-O association was undiminished by this treatment. These experiments used a two-lever, two-outcome design introducing the possibility that devaluation reflected the influence of specific Pavlovian lever-outcome associations. In an attempt to nullify the influence of these incidental Pavlovian cues Experiment 3 used a single bidirectional vertical lever that rats could press left or right for different outcomes. Again, response-independent outcome presentations selectively depressed the performance of the R that delivered the response-independent O. However, in this situation, the response independent O also reduced the sensitivity of R to outcome devaluation; whereas the nondegraded R was sensitive to devaluation, the degraded R was not. We conclude that selective degradation of the instrumental contingency can weaken a specific R-O association while leaving other R-O associations intact. Furthermore, the use of a bidirectional vertical lever in Experiment 3 revealed that unidirectional and spatially separated instrumental manipulanda, such as levers or chains, may produce Pavlovian cues capable of forming incidental associations with the instrumental outcome that can obscure the relative influence of R-O associations after various manipulations. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Condicionamento Operante , Sinais (Psicologia) , Ratos , Animais , Condicionamento Operante/fisiologia , Ratos Long-Evans
7.
J Exp Psychol Anim Learn Cogn ; 48(4): 413-434, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36265027

RESUMO

Six experiments with rats examined the nature of inhibition learned in an operant feature-negative (FN) discrimination. The results of prior experiments that examined instrumental extinction rather than FN learning suggest that inhibition can be very specific to the inhibited response. In Experiment 1, we trained lever-press and chain-pull responses in separate but parallel FN discriminations (AR1+, ABR1-, CR2+, and CDR2-) and then tested both inhibitors (B and D) with both responses. Of primary interest was the extent to which the inhibitors suppressed the response they were trained with (same-response inhibition) versus the other response (cross-response inhibition). We found that cross-response inhibition was robust and essentially equal to same-response inhibition. Experiment 2 replicated this result and confirmed stronger inhibition after FN learning than after a differential inhibition procedure (AR1+, BR1-, CR2+, and DR2-). There was also little evidence that cross-response inhibition was due to a demonstrable competing response. Experiment 3 found that cross-response inhibition did not depend on having the two responses reinforced by a common outcome. Experiments 4 and 5 then found that cross-response inhibition depended substantially (though not completely) on the transfer target response having been trained in its own FN discrimination. However, Experiment 6 found that inhibition after instrumental extinction (as opposed to FN learning) was still highly response-specific when the transferred-to response had been trained in an FN discrimination. The overall results suggest that the characteristics of inhibition in instrumental extinction and FN learning differ and that transfer of FN inhibition across responses depends at least partly on previous "inhibitability" of the target response. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Condicionamento Operante , Extinção Psicológica , Ratos , Animais , Condicionamento Operante/fisiologia , Extinção Psicológica/fisiologia , Aprendizagem , Inibição Psicológica
8.
Sci Rep ; 12(1): 17528, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36266316

RESUMO

Adaptation to our social environment requires learning how to avoid potentially harmful situations, such as encounters with aggressive individuals. Threatening facial expressions can evoke automatic stimulus-driven reactions, but whether their aversive motivational value suffices to drive instrumental active avoidance remains unclear. When asked to freely choose between different action alternatives, participants spontaneously-without instruction or monetary reward-developed a preference for choices that maximized the probability of avoiding angry individuals (sitting away from them in a waiting room). Most participants showed clear behavioral signs of instrumental learning, even in the absence of an explicit avoidance strategy. Inter-individual variability in learning depended on participants' subjective evaluations and sensitivity to threat approach feedback. Counterfactual learning best accounted for avoidance behaviors, especially in participants who developed an explicit avoidance strategy. Our results demonstrate that implicit defensive behaviors in social contexts are likely the product of several learning processes, including instrumental learning.


Assuntos
Aprendizagem da Esquiva , Condicionamento Operante , Humanos , Aprendizagem da Esquiva/fisiologia , Condicionamento Operante/fisiologia , Recompensa , Expressão Facial , Meio Social
9.
PLoS Comput Biol ; 18(10): e1010580, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36191055

RESUMO

Reinforcement learning algorithms have a long-standing success story in explaining the dynamics of instrumental conditioning in humans and other species. While normative reinforcement learning models are critically dependent on external feedback, recent findings in the field of perceptual learning point to a crucial role of internally generated reinforcement signals based on subjective confidence, when external feedback is not available. Here, we investigated the existence of such confidence-based learning signals in a key domain of reinforcement-based learning: instrumental conditioning. We conducted a value-based decision making experiment which included phases with and without external feedback and in which participants reported their confidence in addition to choices. Behaviorally, we found signatures of self-reinforcement in phases without feedback, reflected in an increase of subjective confidence and choice consistency. To clarify the mechanistic role of confidence in value-based learning, we compared a family of confidence-based learning models with more standard models predicting either no change in value estimates or a devaluation over time when no external reward is provided. We found that confidence-based models indeed outperformed these reference models, whereby the learning signal of the winning model was based on the prediction error between current confidence and a stimulus-unspecific average of previous confidence levels. Interestingly, individuals with more volatile reward-based value updates in the presence of feedback also showed more volatile confidence-based value updates when feedback was not available. Together, our results provide evidence that confidence-based learning signals affect instrumentally learned subjective values in the absence of external feedback.


Assuntos
Reforço Psicológico , Recompensa , Condicionamento Operante , Retroalimentação , Humanos
10.
PLoS Comput Biol ; 18(10): e1009945, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36215326

RESUMO

Obsessive-compulsive disorder (OCD) is characterized by uncontrollable repetitive actions thought to rely on abnormalities within fundamental instrumental learning systems. We investigated cognitive and computational mechanisms underlying Pavlovian biases on instrumental behavior in both clinical OCD patients and healthy controls using a Pavlovian-Instrumental Transfer (PIT) task. PIT is typically evidenced by increased responding in the presence of a positive (previously rewarded) Pavlovian cue, and reduced responding in the presence of a negative cue. Thirty OCD patients and thirty-one healthy controls completed the Pavlovian Instrumental Transfer test, which included instrumental training, Pavlovian training for positive, negative and neutral cues, and a PIT phase in which participants performed the instrumental task in the presence of the Pavlovian cues. Modified Rescorla-Wagner models were fitted to trial-by-trial data of participants to estimate underlying computational mechanism and quantify individual differences during training and transfer stages. Bayesian hierarchical methods were used to estimate free parameters and compare the models. Behavioral and computational results indicated a weaker Pavlovian influence on instrumental behavior in OCD patients than in HC, especially for negative Pavlovian cues. Our results contrast with the increased PIT effects reported for another set of disorders characterized by compulsivity, substance use disorders, in which PIT is enhanced. A possible reason for the reduced PIT in OCD may be impairment in using the contextual information provided by the cues to appropriately adjust behavior, especially when inhibiting responding when a negative cue is present. This study provides deeper insight into our understanding of deficits in OCD from the perspective of Pavlovian influences on instrumental behavior and may have implications for OCD treatment modalities focused on reducing compulsive behaviors.


Assuntos
Condicionamento Operante , Transtorno Obsessivo-Compulsivo , Humanos , Teorema de Bayes , Recompensa , Sinais (Psicologia)
11.
Elife ; 112022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36305588

RESUMO

Learning which stimuli (classical conditioning) or which actions (operant conditioning) predict rewards or punishments can improve chances of survival. However, the circuit mechanisms that underlie distinct types of associative learning are still not fully understood. Automated, high-throughput paradigms for studying different types of associative learning, combined with manipulation of specific neurons in freely behaving animals, can help advance this field. The Drosophila melanogaster larva is a tractable model system for studying the circuit basis of behaviour, but many forms of associative learning have not yet been demonstrated in this animal. Here, we developed a high-throughput (i.e. multi-larva) training system that combines real-time behaviour detection of freely moving larvae with targeted opto- and thermogenetic stimulation of tracked animals. Both stimuli are controlled in either open- or closed-loop, and delivered with high temporal and spatial precision. Using this tracker, we show for the first time that Drosophila larvae can perform classical conditioning with no overlap between sensory stimuli (i.e. trace conditioning). We also demonstrate that larvae are capable of operant conditioning by inducing a bend direction preference through optogenetic activation of reward-encoding serotonergic neurons. Our results extend the known associative learning capacities of Drosophila larvae. Our automated training rig will facilitate the study of many different forms of associative learning and the identification of the neural circuits that underpin them.


Assuntos
Condicionamento Operante , Drosophila , Animais , Condicionamento Operante/fisiologia , Drosophila/fisiologia , Larva/fisiologia , Drosophila melanogaster/fisiologia , Condicionamento Clássico/fisiologia
12.
Naunyn Schmiedebergs Arch Pharmacol ; 395(12): 1573-1585, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36100758

RESUMO

By employing a reductionistic (but not simplistic) approach using an established invertebrate model system, the pond snail Lymnaea stagnalis, we investigated whether (1) lipopolysaccharide (LPS)-induced inflammation would cause a sickness state and impair cognitive function, and-if so-(2) would aspirin (acetylsalicylic acid-ASA) restore the impaired cognition. To test our hypotheses, we first determined if the injection of 25 mg (6.25 µg/mL) of Escherichia coli-derived LPS serotype O127:B8 altered homeostatic behavior, aerial respiration, and then determined if LPS altered memory formation when this behavior was operantly conditioned. Next, we determined if ASA altered the LPS-induced changes in both aerial respiration and cognitive functions. LPS induced a sickness state that increased aerial respiration and altered the ability of snails to form or recall long-term memory. ASA reverted the LPS-induced sickness state and thus allowed long-term memory both to be formed and recalled. We confirmed our hypotheses and provided the first evidence in an invertebrate model system that an injection of LPS results in a sickness state that obstructs learning and memory, and this impairment can be prevented by a non-steroidal anti-inflammatory.


Assuntos
Lipopolissacarídeos , Memória , Animais , Lipopolissacarídeos/toxicidade , Condicionamento Operante , Aspirina/farmacologia , Lymnaea , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico
13.
J Exp Anal Behav ; 118(2): 261-277, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36054597

RESUMO

Functional analysis data and previous studies on animal training have demonstrated that social interaction with humans can serve as a reinforcer for animals. Yet, some studies have demonstrated that tactile interaction (e.g., patting, petting, or scratching) is less effective or ineffective when compared to food. However, the reinforcement procedures used may account for these discrepancies. The current study investigated whether tactile interaction, in the form of petting and scratching, could be used as a reinforcer to train behaviors to two horses and a mule. First, each equine learned when reinforcement would be available and what behaviors to engage in during reinforcement delivery. Next, a series of shaping steps and a changing-criterion design were used to test whether tactile interaction could be used to shape two new behaviors, stay and come. All three equines completed reinforcement training and met the mastery criteria for training stay and come. These results demonstrate that tactile interaction can be used as a reinforcer to train equines and also suggest that details of the reinforcement delivery process may be an important consideration when tactile interaction is used as a reinforcer.


Assuntos
Condicionamento Operante , Interação Social , Animais , Cavalos , Humanos , Poaceae , Esquema de Reforço , Reforço Psicológico
14.
Psychopharmacology (Berl) ; 239(11): 3621-3632, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36109391

RESUMO

RATIONALE: Recently, it has been suggested that isoflurane might reduce dopamine release from rat midbrain dopaminergic neurons, the neurobiological substrate implicated in the reinforcing effects of abused drugs and nondrug rewards. However, little is known about effects of isoflurane on neurobehavioral activity associated with chronic exposure to psychoactive substances. OBJECTIVE: The present study was designed to investigate the effects of isoflurane on cocaine-reinforced behavior. Using behavioral paradigm in rats, we evaluated the effects of isoflurane on cocaine self-administration under fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement. We also tested the effects of isoflurane on lever responding by nondrug reinforcers (sucrose and food) in drug-naive rats to control for the nonselective effects of isoflurane on cocaine- and nicotine-taking behavior. To further assess the ability of isoflurane to modulate the motivation for taking a drug, we evaluated the effects of isoflurane on nicotine self-administration. Using different groups of rats, the effects of isoflurane on the locomotor activity induced by a single intraperitoneal injection of cocaine (15 mg/kg) were also examined. RESULTS: Isoflurane significantly suppressed the self-administration of cocaine and nicotine without affecting food consumption. Unlike food-reinforced responding, responding for sucrose reinforcement was decreased by isoflurane. Isoflurane reduced breaking points under a PR schedule of reinforcement in a dose-dependent manner, indicating its efficacy in decreasing the incentive value of cocaine. Isoflurane also attenuated acute cocaine-induced hyperlocomotion. CONCLUSIONS: The results provided evidence that isoflurane decreases cocaine- and nicotine-reinforced responses, while isoflurane effect is not selective for cocaine- and nicotine-maintained responding. These results suggest that isoflurane inhibitions of cocaine- and nicotine-maintenance responses may be related to decreased effects of dopamine, and further investigation will need to elucidate this relationship.


Assuntos
Anestesia , Comportamento Aditivo , Cocaína , Isoflurano , Ratos , Animais , Nicotina/farmacologia , Isoflurano/farmacologia , Dopamina/farmacologia , Ratos Sprague-Dawley , Cocaína/farmacologia , Autoadministração , Sacarose/farmacologia , Esquema de Reforço , Relação Dose-Resposta a Droga , Condicionamento Operante
15.
Pharmacol Biochem Behav ; 220: 173462, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36084838

RESUMO

Cocaine use disorder occurs in an environment where cocaine and other nondrug commodities are concurrently available. Preclinical drug-vs-nondrug choice procedures are one simplified method of modeling this complex clinical environment. The present study established a discrete-trial cocaine-vs-social interaction choice procedure in male and female rats and determined sensitivity of choice behavior to manipulations of reinforcer magnitude and non-contingent "sample" reinforcer presentation. Rats could make up to nine discrete choices between an intravenous cocaine infusion (0.1-1.0 mg/kg/inf) and social interaction with a same-sex social "Partner" rat. Cocaine infusions were available under a progressive-ratio (PR) schedule of reinforcement, and social interaction was available under a fixed-ratio (FR) 3 schedule. Social interaction was chosen over no or small cocaine doses (saline, 0.01 mg/kg/inf) and behavior was reallocated away from social and towards cocaine at larger cocaine doses (1.0 mg/kg/inf). Manipulating social interaction time as one method to alter social reinforcer magnitude did not significantly alter cocaine-vs-social choice. Removing the non-contingent reinforcer presentations before the discrete choice trials also failed to affect cocaine-vs-social choice, suggesting the time interval was sufficient to minimize any potential influence of the non-contingent cocaine infusions on subsequent choice behavior. Overall, the present results were consistent with previous drug-vs-social choice studies and extend our knowledge of environmental factors impacting drug-vs-social choice. Future studies determining the pharmacological sensitivity of cocaine-vs-social choice will be important in expanding the preclinical utility of these procedures for candidate medication drug development.


Assuntos
Cocaína , Animais , Comportamento de Escolha , Cocaína/farmacologia , Condicionamento Operante , Relação Dose-Resposta a Droga , Feminino , Masculino , Ratos , Esquema de Reforço , Autoadministração
16.
Neurosci Biobehav Rev ; 142: 104869, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36108980

RESUMO

Habits are the subject of intense international research. Under the associative dual-process model the outcome devaluation paradigm has been used extensively to classify behaviours as being either goal-directed (sensitive to shifts in the value of associated outcomes) or habitual (triggered by stimuli without anticipation of consequences). This has proven to be a useful framework for studying the neurobiology of habit and relevance of habits in clinical psychopathology. However, in recent years issues have been raised about this rather narrow definition of habits in comparison to habitual behaviour experienced in the real world. Specifically, defining habits as the absence of goal-directed control, the very specific set-ups required to demonstrate habit experimentally and the lack of direct evidence for habits as stimulus-response behaviours are viewed as problematic. In this review paper we address key critiques that have been raised about habit research within the framework of the associative dual-process model. We then highlight novel research approaches studying different features of habits with methods that expand beyond traditional paradigms.


Assuntos
Condicionamento Operante , Hábitos , Humanos , Condicionamento Operante/fisiologia , Processos Mentais , Objetivos
17.
J Exp Anal Behav ; 118(3): 353-375, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36149379

RESUMO

The effects of delivering nondrug alternative reinforcement on resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing were evaluated in two experiments. In both, rats self-administered ethanol by lever pressing in a two-component multiple schedule during baseline. In the Rich component, alternative food reinforcement was made available for performing an alternative response (Experiment 1) or according to a differential-reinforcement-of-other-behavior schedule for lever pressing (Experiment 2). In the Lean component, only ethanol was available. Moreover, the frequency of alternative reinforcement was manipulated across conditions in Experiment 1. Following baseline, lever pressing was extinguished in both components by suspending ethanol reinforcement, and alternative food reinforcers were discontinued. Finally, to test for reinstatement, ethanol reinforcers were delivered independently of lever pressing in both components. In both experiments, proportion-of-baseline response rates were higher during extinction and reinstatement testing in the Rich component than in the Lean component (although differentiation was not observed at the lowest frequency of alternative reinforcement in Experiment 1). Thus, alternative nondrug reinforcers increased resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing, even when those reinforcers were delivered contingently on an alternative response or on abstinence from lever pressing.


Assuntos
Condicionamento Operante , Etanol , Ratos , Animais , Etanol/farmacologia , Extinção Psicológica , Reforço Psicológico , Comportamento Animal , Esquema de Reforço
18.
J Exp Anal Behav ; 118(3): 442-461, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36156248

RESUMO

The present study investigated the effects of variability requirements on learning difficult target sequences in humans. Twenty university students emitted five-response sequences. For the experimental groups, 30 nontarget sequences were reinforced according to the Lag-10 variation criterion or the Lag-3 repetition criterion across conditions. For the control groups, the probability of reinforcers for nontarget sequences was yoked to that obtained by the experimental groups. In addition, for both groups, two difficult target sequences were continuously reinforced. U values were higher with the Lag-10 variation criterion than with the Lag-3 repetition criterion for the experimental groups and were unsystematic for the control groups. Higher U values ​​were accompanied by a random pattern in the emission of nontarget sequences for all groups. Higher levels of variability, regardless of whether they were directly produced by reinforcement or were contingency induced, facilitated learning of difficult target sequences.


Assuntos
Condicionamento Operante , Reforço Psicológico , Humanos , Esquema de Reforço , Aprendizagem , Probabilidade
19.
Pharmacol Res ; 184: 106463, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36162602

RESUMO

Stress alters the level of reward evaluation and seeking. However, the neural circuitry mechanisms underlying stress induced effects on natural reward seeking remain unclear. Here we report a septal-accumbens pathway that mediates the effects of acute stress on reward seeking suppression. We first established the sucrose oral self-administration paradigm and measured the effects of acute stress on reward seeking behavior after 21 days of abstinence. Both forced swimming stress and foot shock stress significantly suppressed the natural reward seeking. Among a variety of brain regions, intermediolateral septum (LSi) appear as a strong stress-responsive area containing abundant c-Fos positive cells; chemogenetic inactivation of LSi reinstated the reward seeking behavior. To elucidate the downstream targets receiving LSi projections, we combined pathway-specific retro-labeling and chemogenetic manipulation to confirm the involvement of LSi-nucleus accumbens (NAc) rather than the Ventral tegmental area (VTA) in mediating the observed behavioral responses. In conclusion, the septal-accumbal projection constitute a discrete circuit dictating the stress evoked alterations on reward seeking and may implicate in treatment of stress induced anhedonia.


Assuntos
Condicionamento Operante , Núcleo Accumbens , Condicionamento Operante/fisiologia , Recompensa , Sacarose/farmacologia , Área Tegmentar Ventral
20.
PLoS One ; 17(9): e0274913, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36178949

RESUMO

Reward based learning is broadly acknowledged to underpin the development and maintenance of addictive behaviour although the mechanism in sexual compulsivity is less understood. Using a Pavlovian-to-Instrumental Transfer (PIT) task we tested whether the motivational aspect of conditioned Pavlovian conditioned stimulus invigorated instrumental responding in relation to specific compatible monetary rewards. Performance on the task was analysed between two groups of males based on Low (N = 38) and High (N = 41) self-report online sexual behaviour (OSB). Psychometric tests including sexual compulsivity scale and behavioural activation/behavioural inhibition (BIS/BAS) were also administered to determine the relationship between OSB and general reward sensitivity. We show clear evidence of acquisition in the Pavlovian and instrumental conditioning phases. Specific transfer effect was greater in the High-OSB group although the difference compared to the Low-OSB group was non-significant. OSB negatively correlated with both BIS and BAS indicative of introversion and low reward sensitivity. OSB positively correlated with sexual compulsivity although it is unclear whether individuals in the High-OSB group considered their behaviour either excessive or problematic. These findings contribute to the ongoing debate regarding the nature of problematic OSB. Fundamental differences in motivational characteristics and mechanism contributing to compulsive behaviour in relation to high-OSB might indicate incompatibility with behavioural addiction models. PIT was not enhanced in high-OSB by appetitive conditioning, although problematic OSB could stem from failure to inhibit actions. Further research should investigate whether aversive conditioning differentially affects responding in high-OSB individuals, potentially explaining perseverant behaviour despite negative consequences.


Assuntos
Comportamento Aditivo , Transferência de Experiência , Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Humanos , Masculino , Recompensa , Comportamento Sexual , Transferência de Experiência/fisiologia
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