Behavioral neuroscience最新文献

N-methyl-D-aspartate (NMDA) receptor antagonists are increasingly used for treating mood disorders, but there is much to learn about their cognitive effects. Research shows NMDA receptor antagonists have varying effects in temporal decision making, either increasing or decreasing optimal choice behaviors related to impulsiveness and delay sensitivity. To clarify their role in these behaviors, we investigated the role of the NMDA receptor antagonist MK-801 in the diminishing returns designed to investigate the ability to delay immediate rewards to optimize total rewards per session. Male and female rats were given the option to choose either a fixed delay lever that returned reward after 10 s or a progressive delay lever that delivered reward with no initial delay but increased by 1 s after each press. The task included two conditions: no-reset where the progressive delay continues to increase and reset where the progressive delay resets to 0 s after an fixed delay press. Following training, rats were injected with MK-801 (0.06 mg/kg, 0.1 mg/kg, 0.2 mg/kg) or saline before a session. In the no-reset condition, rats on the high dose demonstrated impaired choice behavior characterized by frequent nontask related lever presses during delay periods. In the reset condition, males and females on the high dose made more optimal sequences of choices despite females increasing omitted trials. In both conditions, lever press behavior points to a loss of sensitivity to delay intervals driving the observed effects. Overall, results revealed complex effects of sex and NMDA receptor antagonists on optimal foraging behaviors and overall task responsiveness. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

A series of experiments tested the role of sex and cycling ovarian hormones in the renewal of conditioned freezing after either extinction or counterconditioning. In all experiments, conditioning occurred in Context A, response reduction (extinction or counterconditioning) occurred in Context B, and renewal occurred in a familiar yet neutral Context C. Experiment 1a compared renewal after extinction for male and female rats. Both groups demonstrated robust renewal. This finding was replicated in Experiment 1b, which also included a group of ovariectomized female rats to test a potential role of cycling ovarian hormones. Renewal was present and did not differ between groups. Experiment 2 extended these findings to examine renewal after aversive-to-appetitive counterconditioning. Once again, renewal did not differ between male and female rats (Experiment 2a), nor between male, intact female, and ovariectomized female rats (Experiment 2b). For all experiments, summation testing failed to detect differential context-U.S. associations between Contexts B and C. We discuss the role for cycling ovarian hormones in renewal, noting methodological differences with prior studies, and we also discuss how contexts can influence behavior during either extinction or counterconditioning. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Adaptive behavior depends on the ability to predict specific events, particularly those related to rewards. Armed with such associative information, we can infer the current value of predicted rewards based on changing circumstances and desires. To support this ability, neural systems must represent both the value and identity of predicted rewards, and these representations must be updated when they change. Here we tested whether prediction error signaling of dopamine neurons depends on two areas known to represent the specifics of rewarding events, the hippocampus (HC) and orbitofrontal cortex (OFC). We monitored the spiking activity of dopamine neurons in rat ventral tegmental area during changes in the number or flavor of expected rewards designed to induce errors in the prediction of reward value or reward identity, respectively. In control animals, dopamine neurons registered both error types, transiently increasing firing to additional drops of reward or changes in reward flavor. These canonical firing signatures of value and identity prediction errors were altered in rats with ipsilateral neurotoxic lesions of either HC or OFC. Specifically, HC lesions caused a failure to register either type of prediction error, whereas OFC lesions caused abnormally persistent signaling of identity prediction errors and much more subtle effects on signaling of value errors. These results demonstrate that HC and OFC contribute distinct types of information to the computation of prediction errors signaled by ventral tegmental area dopamine neurons. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Deep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM) has been preliminarily investigated as a potential treatment for dementia. The degeneration of NBM cholinergic neurons is a pathological feature of many forms of dementia. Although NBM stimulation has been demonstrated to improve learning, the ideal parameters for NBM stimulation have not been elucidated. This study assesses the differential effects of varying stimulation patterns and duration on learning in a dementia rat model with cholinergic deficits. 192-IgG saporin (SAP) or Dulbecco's phosphate buffered saline was injected into the NBM to produce dementia in rats. Next, all rats underwent unilateral implantation of a DBS electrode in the NBM. The experimental groups consisted of (a) normal, (b) untreated SAP-injected rats with cholinergic deficits, and (c) SAP rats receiving NBM DBS. The stimulation paradigms included testing different modes (tonic and burst) and durations (1 hr, 5 hr, and 24 hr/day) over 10 daily sessions. Memory was assessed using two established learning paradigms: novel object recognition and auditory operant chamber learning. Both normal and stimulated rats demonstrated improved performance in novel object recognition and auditory learning as compared to the unstimulated SAP group. The burst stimulation groups performed better than the tonic group. Increasing the daily stimulation duration to 24 hr did not further improve cognitive performance in an auditory recognition task and degraded the results on a novel object recognition task as compared with 5 hr. The present findings suggest that naturalistic NBM burst DBS may offer potential effective therapy for treating dementia and suggests potential strategies for the reevaluation of current human NBM stimulation paradigms. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The orbitofrontal cortex (OFC) is critical for learning and decision making, but its organization in terms of anatomical connections to other brain areas is not well understood in humans. Here we used diffusion magnetic resonance imaging and probabilistic tractography to characterize the cortical and subcortical white matter connections of the human OFC. We found widespread connectivity of the OFC with frontal and temporal cortices, anterior cingulate, insula, olfactory cortex, as well as the striatum, hippocampus, amygdala, and thalamic nuclei. We then used k-means clustering to parcellate the OFC into different subregions based on these connections, revealing a medial-lateral division with two clusters, and a separation into medial, lateral-anterior, and lateral-posterior subdivisions with three clusters. Higher order parcellations revealed more complex subdivisions mirroring cytoarchitectural boundaries of the primate OFC. Analysis of the white matter connectivity of the medial and lateral OFC clusters revealed differences in their connectivity patterns with frontal cortices, insula, olfactory cortex, anterior cingulate cortex, as well as the striatum and several thalamic nuclei. In addition, lateral-anterior and lateral-posterior OFC clusters showed different connectivity strengths with several frontal cortices, anterior cingulate cortex, insula, and the caudate. These findings suggest parallels between the anatomical organization of the human and macaque OFC and may help to elucidate how the OFC contributes to adaptive behavior. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Individuals differ in sensitivity to the adverse consequences of their actions. We have shown that these differences can be linked to differences in correctly learning causal relationships between actions and their negative consequences. To further assess this, here we used a conditioned punishment task in 195 participants. Explicit punishment contingency information was provided before or after participants had experienced strong (40%) or weak (10%) punishment contingencies. We found the same phenotypes of human punishment learning reported previously (Jean-Richard-Dit-Bressel et al., 2021; Jean-Richard-Dit-Bressel et al., 2023). Early provision of punishment contingency information promoted punishment avoidance under strong punishment contingencies but was relatively ineffective under weak punishment contingencies. This persistent punishment insensitivity despite early contingency information was not due to habit learning or failure to understand the associative task structure. Rather, persistent insensitivity to punishment was due to a failure in integrating punishment contingency knowledge with action selection. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

We have previously demonstrated that gonadally intact female rats become habitual following around 120 response-outcome (R-Os) exposures during operant training. This rapid development of habit does not occur in gonadally intact male rats, which remain goal-directed up to at least 320 R-Os. The present study sought to examine the effect of removing gonadal hormones on the acquisition and expression of goal-directed and habitual behaviors separately in both male and female rats. To accomplish this, separate experimental groups of adult Long-Evans rats were utilized, including intact and ovariectomized (OVX) females, as well as intact and castrated (CAST) males. All groups were trained to 240 R-Os, and one half of each experimental group was subjected to a reinforcer devaluation procedure, while the remaining half served as nondevalued controls. An extinction test was then used to determine habitual versus goal-directed behavior. Results found intact females trained to 240 R-Os showed habit and intact males trained to 240 R-Os showed goal-directed behavior. Results also found that ovariectomy disrupts habit in female rats, keeping them goal-directed at 240 R-Os, while castration in male rats produced habitual responding at 240 R-Os, thus effectively reversing the sex differences observed in intact rats at 240 R-Os. An additional experiment was done in OVX and CAST males trained to 160 R-Os to determine if gonadectomy altered goal/habit behavior earlier in instrumental learning. Results showed that both OVX females and CAST males were goal-directed at 160 R-Os. Overall, these results indicate the lack of ovarian hormones effectively delays habit in female rats, and lack of testicular hormones produces earlier habit in males. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Extinction is fundamental to adaptive behavior in that it allows organisms to alter previously conditioned behaviors based on the prevailing environmental contingencies. Extinguished responses, however, will renew when the conditioned stimulus is presented outside the extinction context. There has been some suggestion that renewal after extinction of appetitive conditioning is a sex-specific process, with only male rats showing renewal (e.g., Anderson & Petrovich, 2015, 2017, 2018). The purpose of the present experiments was to revisit the role of sex in appetitive renewal, in part because an earlier literature demonstrated renewal in experiments with only female rats (e.g., Brooks & Bouton, 1994). In three experiments, rats underwent appetitive Pavlovian conditioning in Context A, followed by extinction in Context B, and then within-subject renewal testing in both B and A. In Experiment 1a, renewal was present for both male and female rats. In Experiment 1b, the procedure included exposures to Context A during the extinction phase. Once again, renewal was observed in female rats. In Experiment 2, we assessed if cycling hormones contribute to renewal in female rats. To do so we compared intact female rats with ovariectomized female rats, and observed robust renewal in both groups. Our results support the notion that renewal is a general behavioral phenomenon, and is one reason why behavior change may be difficult to sustain (Bouton, 2014). (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The neuropeptide oxytocin is traditionally known for its roles in parturition, lactation, and social behavior. Other data, however, show that oxytocin can modulate behaviors outside of these contexts, including drug self-administration and some aspects of cost-benefit decision making. Here we used a pharmacological approach to investigate the contributions of oxytocin signaling to decision making under risk of explicit punishment. Female and male Long-Evans rats were trained on a risky decision-making task in which they chose between a small, "safe" food reward and a large, "risky" food reward that was accompanied by varying probabilities of mild footshock. Once stable choice behavior emerged, rats were tested in the task following acute intraperitoneal injections of oxytocin or the oxytocin receptor antagonist L-368,899. Oxytocin dose-dependently reduced preference for the large, risky reward only in females, whereas L-368,899 dose-dependently reduced preference for the large, risky reward in both sexes. Control experiments showed that these effects could not be accounted for by drug-induced alterations in preference for the large reward or shock sensitivity. Together, these results reveal partially sex-dependent effects of oxytocin signaling on risky decision making in rats. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The social and nonsocial cognitive deficits found in schizophrenia (SZ) and in individuals at risk for the illness are relatively treatment-resistant and yet are the best predictors of real-world functioning. As such, pathophysiological markers that have been shown to be remediable, and associated with cognitive and functional targets, may serve as an indirect approach to improved outcomes. Heart rate variability (HRV), a measure of autonomic adaptability, is suppressed in individuals with SZ and predictive of psychosocial function. Here, we aimed to clarify the relationships between autonomic adaptability, social cognition, and psychosocial dysfunction in individuals who may be at risk for psychosis. HRV was measured before and after a stressor task to assess baseline and recovery, and social cognition was assessed with affective valence recognition in 25 at-risk individuals who report distress to psychotic-like experiences (PLE) and 30 healthy comparisons. PLE demonstrated blunted baseline HRV, worse performance for neutral, but not positive or negative, affective faces, as well as role and social dysfunction. In PLE, significant relationships were found between negative valence accuracy and baseline HRV and role function, as well as between recovery HRV and social and role function. Group classification revealed 70.9% accuracy when using recovery HRV and role function. Results are the first to demonstrate that aberrant autonomic arousal is predictive of maladaptive social cognitive and functional behaviors in individuals who may be at risk for psychosis. Early identification of those at risk may mitigate functional decline. (PsycInfo Database Record (c) 2025 APA, all rights reserved).