Research

Primary rewards and aversive outcomes have comparable effects on attentional bias.

Attention is biased toward stimuli previously associated with reward. The same is true for aversive conditioning; stimuli previously associated with an aversive outcome also bias attention, suggesting that motivational salience guides attention. Most research that supports this conclusion has manipulated monetary gain—a secondary reinforcer—for reward learning, and electric shocks—a primary punisher—for aversive conditioning, making it difficult to directly compare their influence on attention. Therefore, in the present study, we matched for reinforcer dimensions by using primary taste as reinforcers/punishers and assessed their influence on attention. In a training phase, participan...
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Chemogenetic activation of lateral habenula accelerates the extinction of the appetitive conditioned responses.

A previous study reported lateral habenula (LHb) lesions decelerated appetitive extinction. Therefore, we examined whether LHb activation accelerated appetitive extinction. In this study, rats received appetitive Pavlovian conditioning, pairing a conditioned stimulus (CS, light) with an unconditioned stimulus (food pellets), followed by CS-alone presentations. Chemogenetic LHb activation accelerated the decline in conditioned food-cup responses during extinction. The present results and the reports of previous LHb lesion studies suggest that LHb mediates appetitive extinction. (PsycInfo Database Record (c) 2023 APA, all rights reserved)
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A history of ethanol intake accelerates the development of morphine analgesic tolerance: A protective potential for omega-3 fatty acids.

Adolescence is a critical life period during which significant neurodevelopmental changes occur within the central nervous system. Consistently, substance abuse in this stage has been found to induce persistent changes in brain responsiveness to future drug challenges. Nowadays, heavy episodic alcohol consumption during adolescence, also known as binge-drinking behavior, is a growing concern in modern societies. On the other hand, alcohol is well known to act as a gateway drug, that is, it promotes the individual’s craving for consumption of other drugs of abuse. With this in mind, we aimed to assess whether adolescent ethanol exposure could alter the development of tolerance and dependenc...
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Pair housing does not alter incubation of craving, extinction, and reinstatement after heroin self-administration in female and male rats.

Evidence suggests that single housing in rats acts as a chronic stressor, raising the possibilities that it contributes to measures of heroin craving and that pair housing ameliorates such measures. This study aimed to determine whether pair housing after heroin self-administration reduces the incubation of craving, extinction, and reinstatement of heroin seeking. Single-housed female and male Sprague-Dawley rats underwent daily 6-hr heroin self-administration, wherein active lever presses produced a heroin infusion paired with light/tone cues. One day after self-administration, rats underwent a baseline cued-seeking test wherein active lever presses only produced light/tone cues. Immediatel...
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Use of magnetic resonance spectroscopy to explore metacognitive ability.

Previous studies have reported the importance of the precuneus in mediating metacognition and the prefrontal cortex in decision-making tasks. However, the mechanisms underlying metacognition remain to be fully elucidated. N-acetyl aspartate/creatine + phosphocreatine (NAA/Cr + PCr) is a putative neuronal marker level, which has been used in cognitive disorders. Long echo time proton magnetic resonance spectroscopy was used to further explore the metabolic correlates of metacognition. Metacognition was based on a self-reported questionnaire of nursing students. Magnetic resonance spectra of the bilateral precuneus and medial prefrontal cortex were recorded. A significant positive correlation ...
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The effects of time horizon and guided choices on explore–exploit decisions in rodents.

Humans and animals have to balance the need for exploring new options with exploiting known options that yield good outcomes. This tradeoff is known as the explore–exploit dilemma. To better understand the neural mechanisms underlying how humans and animals address the explore–exploit dilemma, a good animal behavioral model is critical. Most previous rodents explore–exploit studies used ethologically unrealistic operant boxes and reversal learning paradigms in which the decision to abandon a bad option is confounded by the need for exploring a novel option for information collection, making it difficult to separate different drives and heuristics for exploration. In this study, we inve...
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Memory and anxiety-like behavior of rats in the plus-maze discriminative avoidance task: Role of serotonergic transmission in the basolateral amygdala.

Optimal levels of anxiety are critical to memory consolidation, but maladaptive anxiety can disrupt memory acquisition. Serotonergic activity within the amygdala influences both anxiety-like behavior and aversive memory consolidation. To evaluate the effects of serotoninergic manipulations within the basolateral amygdala (BLA) on anxiety-like behavior and aversive memory in rats tested in the plus-maze discriminative avoidance task (PMDAT). The PMDAT investigates aversive memory and anxiety-like behavior simultaneously in rodents. Three-month-old male Wistar rats received bilateral infusions (1 μL per side) of saline, 8-OH-DPAT (5-HT1 agonist; 10 nmol), WAY100135 (5-HT1 antagonist; 0.9 nmol...
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