Behavioral neuroscience最新文献

The n-back task has been widely used to study working memory. Previous studies investigating the electrophysiological (electroencephalogram [EEG]) and hemodynamic correlates (functional near-infrared spectroscopy [fNIRS]) of the n-back task have been generally based on verbal stimuli and only investigated EEG frequency bands. We simultaneously acquired the EEG and fNIRS in 35 participants (16 males; age = 26.4 ± 4.3 years; educational attainment = 18 ± 2 years) during a visuospatial n-back task. The task encompassed a control condition and a low (requiring to recall one previous stimulus) and a high (requiring to recall two previous stimuli) working memory load experimental conditions. Accuracy decreased and reaction times slowed in the high compared to both low load and control conditions. Regarding EEG, P3a showed higher amplitude in the experimental conditions compared to the control one, and P3b exhibited higher amplitude in the low compared to the high load condition. Regarding fNIRS, the high load condition showed higher deoxygenated hemoglobin compared to the control one. Moreover, the central frontopolar cortex showed higher activation compared with the left frontal cortex. Our study showed that working memory load during a visuospatial n-back task influenced behavioral and electrophysiological indices. Even if the load effect was only observed for deoxygenated hemoglobin on hemodynamic data, this was in line with previous studies and coherent with its electrophysiological correlates. Thus, our study confirms that EEG and fNIRS can be successfully used in multimodal acquisitions, but also highlights that future studies are needed to develop a novel version of the task. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pavlovian extinction reduces the performance of conditioned responses and occurs when the conditioned stimulus (CS) is repeatedly presented in the absence of the unconditioned stimulus (US). However, when the CS is experienced in a context that is different from the extinction context, there is a recovery of the conditioned response, a phenomenon known as renewal. There is some evidence that the renewal of appetitive conditioning is influenced by sex, with females failing to exhibit renewed responding. Further, there is recent evidence that renewal of fear might also not occur in female rats. In both appetitive and fear preparations, the lack of renewal in females has been postulated to be related to cycling ovarian hormones. Therefore, in Experiments 1 and 2, we directly compared fear renewal in males and females (Experiment 1) as well as ovariectomized (OVX) females (Experiment 2) when conditioning occurred in Context A, extinction in B, and testing in A (ABA renewal). Experiments 3 and 4 examined renewal when conditioning and extinction occurred in A and testing occurred in B (AAB renewal). In all experiments, renewal was not significantly different between male and female rats. Further, in Experiments 2 and 4, renewal did not differ between males, intact females, and OVX females. Additionally, in each experiment, there was no evidence that context excitation and/or inhibition contributed to renewal; instead suggesting that renewal was controlled by an occasion-setting mechanism. Overall, these results suggest little evidence for the role of sex in renewal of conditioned freezing and also indicate that cycling ovarian hormones have little role in the strength of renewal in female rats. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social isolation can have long-term effects on brain development and behavior and increases the risk of developing clinical conditions, including anxiety disorders. One modulator of the stress response is gamma-aminobutyric acid, an inhibitory neurotransmitter synthesized by glutamic acid decarboxylase (GAD). This study examined sex differences in behavior and GAD expression following prolonged social isolation beginning in adolescence in Long Evans rats. Males and females were equally divided into group-housed (GH) and socially isolated conditions on Postnatal Day 28 (n = 8 per group). Beginning 5 weeks later, tests were conducted for anxietylike behaviors (open-field test and elevated plus maze), social interactions (sociability test), and spatial memory (novel object location). Sex differences in behavior were observed, with GH females showing fewer anxietylike behaviors in the open-field test and elevated plus maze and spending more time with objects (sociability task) compared to GH males. Isolation had no effect on males but increased anxiety and reduced neophilic measures in females, removing sex differences. On the sociability task, all groups spent more time with novel rats compared to objects, suggesting social interest was retained after isolation. In the hippocampus, isolation reduced GAD in both sexes, and sex differences were seen (F > M). However, no group differences in behavior were observed in the hippocampal-dependent novel object location task. Our findings suggest that prolonged social isolation beginning in adolescence is anxiogenic for female Long Evans rats. Furthermore, sex and housing impact hippocampal GABA-ergic activity, which may have important implications in the treatment of anxiety disorders. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dietary maternal deficiency in omega-3 polyunsaturated fatty acids (n-3 PUFA) is a potential risk factor for the development of anxiety and other mood disorders in children and adolescents. Here, we used a previously characterized maternal n-3 PUFA dietary deficiency model in rats to determine the impact of postweaning supplementation on adolescent anxiety-like behaviors. We focused on two models of anxiety: innate anxiety tested by the elevated plus maze and a novel operant model of learned anxiety where animals learn that actions may be associated with a variable probability of harm. Given that recent basic and clinical studies have associated anxiety and other adverse effects of n-3 PUFA deficiency on inflammatory processes and microglial structure and function, we also assessed the impact of our dietary deficiency model and supplementation on adolescent microglial morphology in multiple brain regions. We found that the male and female adolescent n-3 PUFA-deficient groups exhibit increased innate anxiety, but only females showed enhanced learned anxiety. Supplementation after weaning did not significantly affect innate anxiety but ameliorated learned anxiety in females. Thus, the beneficial effects of supplementation on adolescent anxiety may be sex-specific and depend on the type of anxiety. We also found that n-3 PUFA deficiency influences microglia function in adolescents in the amygdala and nigrostriatal, but not mesolimbic, brain regions. Collectively, these data suggest that while n-3 PUFA dietary supplementation may be effective in reducing adolescent anxiety, this effect is context-, sex-, and brain network-specific. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

In our modern environment, we are bombarded with stimuli or cues that exert significant influence over our actions. The extent to which such cues attain control over or disrupt goal-directed behavior is dependent on several factors, including one's inherent tendencies. Using a rodent model, we have shown that individuals vary in the value they place on stimuli associated with reward. Some individuals, termed "goal-trackers," primarily attribute predictive value to reward cues, whereas others, termed "sign-trackers," attribute predictive and incentive value. Thus, for sign-trackers, the reward cue is transformed into an incentive stimulus that is capable of eliciting maladaptive behaviors. The sign-tracker/goal-tracker animal model has allowed us to refine our understanding of behavioral and computational theories related to reward learning and to parse the underlying neural processes. Further, the neurobehavioral profile of sign-trackers is relevant to several psychiatric disorders, including substance use disorder, impulse control disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, and posttraumatic stress disorder. This model, therefore, can advance our understanding of the psychological and neurobiological mechanisms that contribute to individual differences in vulnerability to psychopathology. Notably, initial attempts at translation-capturing individual variability in the propensity to sign-track in humans-have been promising and in line with what we have learned from the animal model. In this review, we highlight the pivotal role played by the sign-tracker/goal-tracker animal model in enriching our understanding of the psychological and neural basis of motivated behavior and psychiatric symptomatology. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Before we can make any choice, we must gather information from the environment about what our options are. This information-gathering process is critically mediated by attention, and our attention is, in turn, shaped by our previous experiences with-and learning about-stimuli and their consequences. In this review, we highlight studies demonstrating a rapid and automatic influence of reward learning on attentional capture and argue that these findings provide a human analog of sign-tracking behavior observed in nonhuman animals-wherein signals of reward gain incentive salience and become attractive targets for attention (and overt behavior) in their own right. We then consider the implications of this idea for understanding the drivers of cue-controlled behavior, with focus on addiction as a case in which choices with regard to reward-related stimuli can become injurious to health. We argue that motivated behavior in general-and addiction in particular-can be understood within a "biased competition" framework: Different options and outcomes compete for attentional priority as a function of top-down goals, bottom-up salience, and prior experience, and the winner of this competition becomes the target for subsequent outcome-directed and flexible behavior. Finally, we outline the implications of the biased-competition framework for cognitive, behavioral, and socioeconomic interventions for addiction. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

There is a growing number of studies investigating discriminatory fear conditioning and conditioned inhibition of fear to assess safety learning, in addition to extinction of cued fear. Despite all of these paradigms resulting in a reduction in fear expression, there are nuanced differences among them, which could be mediated through distinct behavioral and neural mechanisms. These differences could impact how we approach potential treatment options in clinical disorders with dysregulated fear responses. The objective of this review is to give an overview of the conditional discrimination and inhibition findings reported in both animal models and human neuropsychiatric disorders. Both behavioral and neural findings are reviewed among human and rodent studies that include conditional fear discrimination via conditional stimuli with and without reinforcement (CS+ vs. CS-, respectively) and/or conditional inhibition of fear through assessment of the fear response to a compound CS-/CS+ cue versus CS+. There are several parallels across species in behavioral fear expression as well as neural circuits promoting fear reduction in response to a CS- and/or CS-/CS+ compound cue. Continued and increased efforts to compare similar behavioral fear inhibition paradigms across species are needed to make breakthrough advances in our understanding and treatment approaches to individuals with fear disorders. (PsycInfo Database Record (c) 2024 APA, all rights reserved).