Behavioral neuroscience最新文献

The amygdala and orbitofrontal cortex (OFC) are interconnected regions that serve as key nodes in brain circuits supporting social and affective behaviors. An important question that has come into focus is whether these regions also play a fundamental role in responding to novelty. One possibility is that these regions are important for discriminating novel from familiar stimuli. An alternative possibility is that these regions contribute to affective responses to stimuli in novelty-based tasks. For example, the amygdala and OFC could contribute to assessing novel stimuli as being threatening or previously selected stimuli as having reward value. The present study tested rhesus macaque monkeys with damage to the amygdala or OFC, along with sham-operated control monkeys, across six variants of novelty-based memory tasks. The results showed that monkeys with damage to the amygdala or OFC performed better overall than control monkeys across the tasks. The results indicated that neither region was essential for discriminating novel from familiar stimuli. Instead, the findings suggested that the improved performance observed in novelty-based tasks following damage to these regions was more likely attributable to influences on affect. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The main psychoactive compound within the cannabis plant, Δ9-tetrahydrocannabinol (THC), is thought to drive both the sensation of "high" and the cognitive impairments associated with cannabis consumption. Researchers keen to understand how cannabis impairs cognition have, therefore, studied the behavioral effects of systemic injections of THC in animal models. However, cannabis contains multiple other cannabinoids which may critically modulate the resulting cognitive effects. Users also typically eat or smoke cannabis, leading to concern over the translational validity of pure THC injections. We, therefore, tested whether acute oral administration of two different commercially available cannabis extracts, marketed as C. indica or C. sativa, decreased male Long-Evans rats' willingness to exert greater cognitive effort in order to maximize reward earned, as expected from previous experiments using injected THC. Both oils were matched for THC and cannabidiol content. While both cannabis products slowed response times at higher doses, only C. indica oil at the highest dose administered (10 mg/kg THC) decreased the number of trials on which rats chose to complete high-effort/high-reward trials. Repeated dosing with a medium dose of either cannabinoid product (3 mg/kg THC) did not influence choice. Ex vivo analyses confirmed comparable levels of brain THC after C. indica or C. sativa administration. Although controversial in the field, these results support the suggestion that products marketed as different cannabis cultivars have dissociable cognitive effects that may not resemble pure THC and emphasize the importance of the route of administration in experimental design. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Do we preferentially learn from outcomes that confirm our choices? In recent years, we investigated this question in a series of studies implementing increasingly complex behavioral protocols. The learning rates fitted in experiments featuring partial or complete feedback, as well as free and forced choices, were systematically found to be consistent with a choice-confirmation bias. One of the prominent behavioral consequences of the confirmatory learning rate pattern is choice hysteresis: that is, the tendency of repeating previous choices, despite contradictory evidence. However, choice-confirmatory pattern of learning rates may spuriously arise from not taking into consideration an explicit choice (gradual) perseveration term in the model. In the present study, we reanalyze data from four published papers (nine experiments; 363 subjects; 126,192 trials), originally included in the studies demonstrating or criticizing the choice-confirmation bias in human participants. We fitted two models: one featured valence-specific updates (i.e., different learning rates for confirmatory and disconfirmatory outcomes) and one additionally including gradual perseveration. Our analysis confirms that the inclusion of the gradual perseveration process in the model significantly reduces the estimated choice-confirmation bias. However, in all considered experiments, the choice-confirmation bias remains present at the meta-analytical level, and significantly different from zero in most experiments. Our results demonstrate that the choice-confirmation bias resists the inclusion of a gradual perseveration term, thus proving to be a robust feature of human reinforcement learning. We conclude by pointing to additional computational processes that may play an important role in estimating and interpreting the computational biases under scrutiny. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The mechanisms underlying chronic psychiatric-like impairments after traumatic brain injury (TBI) are currently unknown. The goal of the present study was to assess the role of diet and the gut microbiome in psychiatric symptoms after TBI. Rats were randomly assigned to receive a high-fat diet (HFD) or calorie-matched low-fat diet (LFD). After 2 weeks of free access, rats began training on the rodent gambling task (RGT), a measure of risky decision-making and motor impulsivity. After training, rats received a bilateral frontal TBI or a sham procedure and continued postinjury testing for 10 weeks. Fecal samples were collected before injury and 3-, 30-, and 60 days postinjury to evaluate the gut microbiome. HFD altered the microbiome, but ultimately had low-magnitude effects on behavior and did not modify functional outcomes after TBI. Injury-induced functional deficits were far more robust; TBI substantially decreased optimal choice and increased suboptimal choice and motor impulsivity on the RGT. TBI also affected the microbiome, and a model comparison approach revealed that bacterial diversity measured 3 days postinjury was predictive of chronic psychiatric-like deficits on the RGT. A functional metagenomic analysis identified changes to dopamine and serotonin synthesis pathways as a potential candidate mechanism. Thus, the gut may be a potential acute treatment target for psychiatric symptoms after TBI, as well as a biomarker for injury and deficit severity. However, further research will be needed to confirm and extend these findings. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

As a hallmark characteristic of schizophrenia, abnormal perception of time is thought to arise from cognitive impairment; however, the absence of translational models indexing this pathological relationship creates barriers to understanding the functional and biological bases of timing impairments. Here, we investigate the relationship between timing and cognition using the maternal immune activation (MIA) rat model of schizophrenia. We additionally investigate the role of prefrontal cortex L-arginine metabolism in these processes via high-performance liquid chromatography and liquid chromatography/mass spectrometry. Results revealed that MIA rats exhibit greater underestimation of interval durations (2-8 s); greater underestimation corresponded with declines in sustained attention capacity. Working memory impairments were not found to contribute to timing deficits. These findings represent the first direct identification of a timing-attention relationship within rodents and are discussed with respect to the dopamine hypothesis of temporal pace. We also found that MIA exposure altered aspects of arginine metabolism as observed in schizophrenia, and we present preliminary evidence suggesting that these changes have functional consequences for cognition. These findings support the MIA rat model as a valuable tool for future investigations exploring the biological instantiation of interrelated timing and cognitive deficits in schizophrenia. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The COVID-19 pandemic is an ongoing stressor that has resulted in the exacerbation of mental health problems worldwide. However, longitudinal studies that identify preexisting behavioral and neurobiological factors associated with mental health outcomes during the pandemic are lacking. Here, we examined associations between prepandemic coping strategy engagement and frontolimbic circuitry with internalizing symptoms during the pandemic. In 85 adults (71.8% female; age 18-30 years), we assessed prototypically adaptive coping strategies (Connor-Davidson Resilience Scale), resting-state functional magnetic resonance imaging functional connectivity (FC) of frontolimbic circuitry, and depression and anxiety symptoms (Beck Depression Inventory, Screen for Child Anxiety-Related Emotional Disorders-Adult, respectively). We conducted general linear models to test preregistered hypotheses that (1) lower coping engagement prepandemic and (2) weaker frontolimbic FC prepandemic would predict elevated symptoms during the pandemic; and (3) coping would interact with FC to predict symptoms during the pandemic. Depression and anxiety symptoms worsened during the pandemic (ps < .001). Prepandemic adaptive coping engagement and frontolimbic FC were not associated with depression or anxiety symptoms during the pandemic (uncorrected ps > .05). Coping interacted with insula-rostral anterior cingulate cortex (ACC) FC (p = .003, pFDR = .014) and with insula-ventral ACC FC (p < .001, pFDR < .001) to predict depression symptoms, but these findings did not survive FDR correction after removal of outliers. Findings from our preregistered study suggest that specific prepandemic factors, particularly adaptive coping and frontolimbic circuitry, are not robustly associated with emotional responses to the pandemic. Additional studies that identify preexisting neurobehavioral factors implicated in mental health outcomes during global health crises are needed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Repetitive bouts of binge drinking can lead to neuroplastic events that alter ethanol's pharmacologic effects and perpetuate excessive consumption. The corticotropin-releasing factor (CRF) system is an example of ethanol-induced neuroadaptations that drive excessive ethanol consumption. Our laboratory has previously shown that CRF antagonist, when infused into the central amygdala (CeA), reduces binge-like ethanol consumption. The present study extends this research by assessing the effects of silencing CRF-producing neurons in CeA on binge-like ethanol drinking stemming from "Drinking in the Dark" (DID) procedures. CRF-ires-Cre mice underwent surgery to infuse G_i/o-coupled Designer Receptors Exclusively Activated by Designer Drugs (DREADD) virus or a control virus into either the CeA or basolateral amygdala (BLA). G_i/o-DREADD-induced CRF-neuronal inhibition in the CeA resulted in a 33% decrease in binge-like ethanol consumption. However, no effect on ethanol consumption was seen after DREADD manipulation in the BLA. Moreover, CeA CRF-neuronal inhibition had no effect on sucrose consumption. The effects of silencing CRF neurons in the CeA on ethanol consumption are not secondary to changes in motor function or anxiety-like behaviors as assessed in the open-field test (OFT). Finally, the DREADD construct's functional ability to inhibit CRF-neuronal activity was demonstrated by reduced ethanol-induced c-Fos following DREADD activation. Together, these data suggest that the CRF neurons in the CeA play an important role in binge ethanol consumption and that inhibition of the CRF-signaling pathway remains a viable target for manipulating binge-like ethanol consumption. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Successful navigation depends critically upon two broad categories of spatial navigation strategies that include allocentric and egocentric reference frames, relying on external or internal spatial information, respectively. As with older adults, aged rats show robust impairments on a number of different spatial navigation tasks. There is some evidence that these navigation impairments are accompanied by a bias toward relying on egocentric over allocentric navigation strategies. To test the degree to which young and aged animals utilize these two navigation approaches, a novel behavioral arena was used in which rats are trained to traverse a circular track and to stop at a learned goal location that is fixed with respect to a panorama of visual cues projected onto the surrounding walls. By instantaneously rotating the cues, allocentric and egocentric reference frames were put in direct and immediate conflict and goal navigation performance was assessed with respect to how accurately young and aged animals were able to utilize the rotated cues. Behavioral data collected from nine young and eight aged animals revealed that both age groups were able to update their navigation performance following cue rotation. Contrary to what was expected, however, aged animals showed more accurate overall goal navigation performance, stronger allocentric strategy use, and more evident changes in behavior in response to cue rotation compared to younger animals. The young rats appeared to mix egocentric and allocentric strategies for ICR task solution. (PsycInfo Database Record (c) 2022 APA, all rights reserved).