Involvement of the ventral tegmental area but not periaqueductal gray matter in the paradoxical rewarding and aversive effects of morphine.
The paradoxical effects of reward and aversion with abused drugs may interact to produce drug addiction, which is the so-called paradoxical effect hypothesis of abused drugs. However, there is no research examining how the ventral tegmental area (VTA) or periaqueductal gray matter (PAG) regulates morphine’s paradoxical effect of reward and aversion. The present study addresses this issue, utilizing a high concentration of N-methyl-D-aspartic acid (NMDA) via injections to destroy the VTA or the PAG. Moreover, the study employed the new “pre- and postassociation” experimental paradigm (2010) to test whether the simulta...
Source: Behavioral Neuroscience - July 29, 2021 Category: Neuroscience Source Type: research
Social buffering of plasma corticosterone and amygdala responses of young rats following exposure to periorbital shock: Implications for eyeblink conditioning development.
The developmental onset of aversive learning processes depends on complex interactions between endocrine, neural, and social influences. Emergence of avoidance conditioning in rat pups is triggered by elevated plasma corticosterone activating the amygdala. Further, the mother’s ability to buffer the corticosterone response delays the onset of avoidance in ˜2-week-old pups. Eyeblink conditioning (EBC) also develops during the pre-weaning period. In previous work, little or no conditioning was observed on Day 17 for pups housed in the home cage with mother and littermates between training sessions, whereas pups isolated b...
Source: Behavioral Neuroscience - July 29, 2021 Category: Neuroscience Source Type: research
Sex differences in conditioned orienting and the role of estradiol in addiction-related behaviors.
Conditioned orienting response (OR) is a form of cue-directed behavior thought to indicate increased attentional and/or motivational processing of reward-associated stimuli. OR as a phenotype has been shown to predict both direct drug proclivity in female rats and behaviors indirectly related to drug proclivity in male rats, but no extant research has compared males and females in terms of their OR behavior or its notable substrates. As females are at increased risk for substance abuse, and the ovarian hormone estradiol is often cited as a driving factor for this predilection, it is important to characterize sex difference...
Source: Behavioral Neuroscience - July 22, 2021 Category: Neuroscience Source Type: research
Repeated, moderate footshock reduces the propensity to relapse to alcohol seeking in female, but not male, iP rats.
This study examined relapse-like behavior in male and female alcohol-preferring iP rats following punishment-imposed voluntary abstinence to alcohol seeking. We focused on alcohol seeking in the punishment-associated environment after prolonged abstinence. Finally, we sought to understand the predictability of relapse-like behavior by examining AUD comorbidities, namely, anxiety-like behavior and the response to repeated, moderate punishment. We found no sex differences in operant self-administration of alcohol. However, we did find a reduced propensity to relapse in the punishment-associated environment in female rats fol...
Source: Behavioral Neuroscience - July 22, 2021 Category: Neuroscience Source Type: research
Assessment of distinct subcortical and cortical contributions to affect and approach/withdrawal behavior by means of resting-state functional connectivity approach.
The relevance of subcortical structures and interhemispheric subcortical–cortical interactions among positive/negative affect and approach/withdrawal tendencies during resting-state are not fully understood. Gaining this knowledge may foster the know-how on their role in subsequent task-engagement and also on the interlinkage among affective measures and approach/withdrawal dichotomy. Here we performed a study based on Region of Interest (ROI)-based analysis and graph-theory estimates for global and subnetworks on a limited sample of healthy 50 male volunteers who recorded resting functional magnetic resonance imaging (f...
Source: Behavioral Neuroscience - July 22, 2021 Category: Neuroscience Source Type: research
The dorsal subiculum is not necessary for step-through inhibitory avoidance acquisition and consolidation in rats.
The dorsal subiculum (DSub) has reciprocal connections with the dorsal hippocampus, and these regions play a role in spatial representation in contextual fear conditioning (CFC). Recently, we used AP5 and muscimol infusions to show that the DSub is required for CFC consolidation. The CFC component can be present in other learning tasks, such as step-through inhibitory avoidance (ST IA), which requires the dorsal hippocampus for acquisition and consolidation. This suggests that the DSub may be also involved in ST IA if the CFC component of the protocol is strong enough. Therefore, this study tested whether the DSub particip...
Source: Behavioral Neuroscience - July 22, 2021 Category: Neuroscience Source Type: research
Orbitofrontal cortex and learning predictions of state transitions.
The orbitofrontal cortex (OFC) has been implicated in goal-directed planning and model-based decision-making. One key prerequisite for model-based decision-making is learning the transition structure of the environment—the probabilities of transitioning from one environmental state to another. In this work, we investigated how the OFC might be involved in learning this transition structure, by using fMRI to assess OFC activity while humans experienced probabilistic cue–outcome transitions. We found that OFC activity was indeed correlated with behavioral measures of learning about transition structure. On a trial-by-tri...
Source: Behavioral Neuroscience - July 22, 2021 Category: Neuroscience Source Type: research
Autonomic arousal tracks outcome salience not valence in monkeys making social decisions.
The evolutionary and neural underpinnings of human prosociality are still being identified. A growing body of evidence suggests that some species find the sight of another individual receiving a reward reinforcing, called vicarious reinforcement, and that this capacity is supported by a network of brain areas including the anterior cingulate cortex (ACC) and the amygdala. At the same time, analyses of autonomic arousal have been increasingly used to contextualize and guide neural research, especially for studies of reward processing. Here, we characterized the autonomic pupil response of eight monkeys across two laboratori...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
A novel model of obesity prediction: Neurobehaviors as targets for treatment.
Obesity is a worldwide epidemic that is on the rise, with approximately 30% of the world population classified as either overweight or obese. The United States has some of the highest rates of obesity, and in most countries in the world, obesity now poses more of a serious health concern than malnutrition. Obesity is a chronic, relapsing disorder that is both preventable and treatable; however, traditional interventions that target eating less and exercising more have low success rates, especially in the long term. Therefore, identifying the neurobehaviors that predict obesity is important to help identify targets to decre...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Phasic inhibition of dopamine neurons is an instrumental punisher.
It is well established that the activity of VTA dopamine neurons is sufficient to serve as a Pavlovian reinforcer but whether this activity can also serve as instrumental reinforcer is less well understood. Here we studied the effects of optogenetic inhibition of VTA dopamine neurons in instrumental conditioning preparations. We show that optogenetic inhibition of VTA dopamine neurons causes a response-specific, contingency-sensitive suppression of instrumental responding. This suppression was due to instrumental response, not Pavlovian stimulus, learning and could not be attributed to deepened instrumental extinction lear...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Effect of simple and complex enrichment added to standard-sized cages in behavioral, physiological, and neurological variables in female Swiss mice (Mus musculus).
Environmental enrichment (EE) has been a widely used tool to improve animal welfare, as well as to study brain plasticity. Traditional EE settings in the field of neuroscience employ highly complex cages with numerous objects and increased space, whereas more simple additions included for the control treatment are rarely considered in the experimental design. This leads to a lack of consistency of what neuroscientists designate as “standard housing,” which might compromise the reproducibility of the results. Therefore, we employed standard-sized cages to study how different EE configurations can affect several biologic...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Dopamine D2R upregulation in ventral striatopallidal neurons does not affect Pavlovian or go/no-go learning.
Ventral striatal dopamine is thought to be important for associative learning. Dopamine exerts its role via activation of dopamine D1 and D2 receptors in the ventral striatum. Upregulation of dopamine D2R in ventral striatopallidal neurons impairs incentive motivation via inhibiting synaptic transmission to the ventral pallidum. Here, we determined whether upregulation of D2Rs and the resulting impairment in ventral striatopallidal pathway function modulates associative learning in an auditory Pavlovian reward learning task as well as Go/No-Go learning in an operant based reward driven Go/No-Go task. We found that upregula...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Regulation of maternal care by corticotropin-releasing factor receptors in the dorsal raphe nucleus in mice.
We previously reported that the dorsal raphe nucleus (DRN) was involved in the regulation of maternal care in lactating female mice. The DRN receives multiple innervations from a variety of the brain regions. Corticotropin-releasing factor (CRF) Type 1 and Type 2 receptors are distributed in the DRN. Both receptors have been implicated in regulating negative aspects including stress, fear, and anxiety. However, it remains unknown how CRF receptors in the DRN regulate maternal care. In the present study, we investigated how CRF receptors in the DRN is involved in regulating maternal care in lactating female mice. Injection ...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Optogenetic stimulation of the basolateral amygdala accelerates acquisition of object-context associations.
The basolateral complex of the amygdala (BLA) is capable of modulating memory and is thought to do so via projections to regions such as the hippocampus. The present study used optogenetic stimulation of glutamatergic projection neurons in the BLA as rats learned object-context associations during a well-studied hippocampus-dependent memory task. Relative to a control condition, optogenetic BLA stimulation resulted in the accelerated acquisition of when stimulation was delivered following correct choices but not when it was delivered during the intertrial interval. These results extend prior examples of amygdala-mediated m...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
Contributions of postrhinal and perirhinal cortex to contextual information processing.
The role of the postrhinal cortex (POR) and the perirhinal cortex (PER) in processing relational or contextual information was examined with Pavlovian fear conditioning. Rats with electrolytic or neurotoxic lesions of the POR or PER were tested in 2 contextual fear conditioning paradigms. In Experiment 1, electrolytic lesions of the POR or PER produced impairments in contextual fear conditioning but not in conditioning to a phasic auditory conditioned stimulus. Neurotoxic lesions of the POR or PER likewise resulted in anterograde (Experiment 2) and retrograde (Experiment 3) deficits in fear conditioning to the training con...
Source: Behavioral Neuroscience - July 15, 2021 Category: Neuroscience Source Type: research
