Noradrenergic regulation of two-armed bandit performance.
Reversal learning depends on cognitive flexibility. Many reversal learning studies assess cognitive flexibility based on the number of reversals that occur over a test session. Reversals occur when an option is repeatedly chosen, e.g., eight times in a row. This design feature encourages win-stay behavior and thus makes it difficult to understand how win-stay decisions influence reversal performance. We used an alternative design, reversals over blocks of trials independent of performance, to study how perturbations of the medial orbital cortex and the noradrenergic system influence reversal learning. We found that choice ...
Source: Behavioral Neuroscience - October 14, 2021 Category: Neuroscience Source Type: research
Differences in dopamine and opioid receptor ratios in the nucleus accumbens relate to physical contact and undirected song in pair-bonded zebra finches.
Long-term social bonds are critical for survival and reproductive success in many species. Although courtship and pair-bond formation are relatively well studied, much less is known about the neural regulation of behaviors that occur after pair bonding that reinforce the bond and contribute to reproductive success. Dopamine and opioids in the nucleus accumbens (NAc) alter motivational state and reward by binding to receptor subtypes that engage distinct and opposing second messenger systems, and there is evidence that receptor ratios may influence social behavior. We used quantitative real-time PCR to explore relationships...
Source: Behavioral Neuroscience - October 7, 2021 Category: Neuroscience Source Type: research
Amygdala or hippocampus damage only minimally impacts affective responding to threat.
Decades of research studying the behavioral effects of damage to structures in medial temporal lobe of rhesus monkeys have documented that such damage, particularly damage to the amygdala, causes animals to become hyporesponsive to threat and hyper-social. This phenotype, a subset of the behaviors known as “Klüver-Bucy Syndrome,” is one of the most well-known phenomena in behavioral neuroscience. Carrying on the tradition of evaluating hyposensitivity to threat in monkeys with temporal lobe lesions, we evaluated the responses of rhesus monkeys with bilateral ibotenic acid lesions of the amygdala or hippocampus and pro...
Source: Behavioral Neuroscience - October 7, 2021 Category: Neuroscience Source Type: research
Reinforcement learning modeling reveals a reward-history-dependent strategy underlying reversal learning in squirrel monkeys.
Insight into psychiatric disease and development of therapeutics relies on behavioral tasks that study similar cognitive constructs in multiple species. The reversal learning task is one popular paradigm that probes flexible behavior, aberrations of which are thought to be important in a number of disease states. Despite widespread use, there is a need for a high-throughput primate model that can bridge the genetic, anatomic, and behavioral gap between rodents and humans. Here, we trained squirrel monkeys, a promising preclinical model, on an image-guided deterministic reversal learning task. We found that squirrel monkeys...
Source: Behavioral Neuroscience - September 27, 2021 Category: Neuroscience Source Type: research
Individual differences in neurocognitive aging in outbred male and female long-evans rats.
Individual differences in biology as well as experience and exposures throughout life may contribute risk or resilience to neurocognitive decline in aging. To investigate the role of sex as a biological variable in cognitive function due to normal aging, we used substantial cohorts of healthy male and female aged outbred rats maintained under similar conditions throughout life to assess whether both sexes display a similar distribution of individual differences in behavioral performance using a water maze task optimized to assess hippocampal-dependent cognition in aging. We found both aged male and female rats performed po...
Source: Behavioral Neuroscience - September 23, 2021 Category: Neuroscience Source Type: research
In vivo microdialysis shows differential effects of prenatal protein malnutrition and stress on norepinephrine, dopamine, and serotonin levels in rat orbital frontal cortex.
Prenatal protein malnutrition (PPM) alters the developing brain including changes in monoaminergic systems and attention. In the present study, we used in vivo microdialysis to examine the relationship between PPM, acute stress, and extracellular serotonin (5HT), dopamine (DA) and norepinephrine (NE) in both hemispheres of lateral orbital frontal cortices (lOFC) in the adult rat. We hypothesized that prenatal protein malnutrition would alter extracellular concentrations of cortical monoamines. The effects of an acute restraint stress were also assessed because PPM alters the brain’s response to stress. We used adult male...
Source: Behavioral Neuroscience - September 16, 2021 Category: Neuroscience Source Type: research
Physical exercise and catecholamine reuptake inhibitors affect orienting behavior and social interaction in a rat model of attention-deficit/hyperactivity disorder.
The effects of methylphenidate (MPH), atomoxetine (ATMX), and/or physical exercise (EX) on orienting behavior and social interaction were examined in spontaneously hypertensive rats (SHRs), a commonly used animal model of attention-deficit/hyperactivity disorder (ADHD). During the orienting procedure, rats received repeated presentations of a nonreinforced visual stimulus. As observed previously, orienting behavior (rearing up on the hind legs) habituated across trials in normo-active control rats (Wistars) but not in SHRs, suggesting that SHRs have difficulty ignoring irrelevant behavioral stimuli. Treatment with MPH (0.1...
Source: Behavioral Neuroscience - September 16, 2021 Category: Neuroscience Source Type: research
Inheritance of hormonal stress response and temperament in infant rhesus macaques (Macaca Mulatta): Nonadditive and sex-specific effects.
Objective: Early life interindividual variation in hypothalamic-pituitary-adrenal (HPA) reactivity to stress is predictive of later life psychological and physical well-being, including the development of many pathological syndromes that are often sex-biased. A complex and interactive set of environmental and genetic causes for such variation has been implicated by previous studies, though little attention has been paid to nonadditive effects (e.g. dominance, X-linked) or sex-specific genetic effects. Method: We used a large pedigreed sample of captive 3–4 months old infant rhesus macaques (N = 2,661, 54% female) to fit ...
Source: Behavioral Neuroscience - September 13, 2021 Category: Neuroscience Source Type: research
Ambiguity and conflict: Dissecting uncertainty in decision-making.
Making decisions is fundamental to how we navigate, survive, and thrive in our environment. The quality of information used to support decisions is rarely perfect. Many decisions are made under conditions of uncertainty, arising from ambiguous or conflicting information. Conflict and ambiguity, though conceptually distinct, both generate uncertainty, a commonality that has led to overlapping and inconsistent terminology in the literature. Evidence from human and animal research suggests a behavioral dissociation in responding to conflict and ambiguity. This dissociation can be studied through the implementation of spatial ...
Source: Behavioral Neuroscience - September 13, 2021 Category: Neuroscience Source Type: research
Unique features of stimulus-based probabilistic reversal learning.
Reversal learning paradigms are widely used assays of behavioral flexibility with their probabilistic versions being more amenable to studying integration of reward outcomes over time. Prior research suggests differences between initial and reversal learning, including higher learning rates, a greater need for inhibitory control, and more perseveration after reversals. However, it is not well-understood what aspects of stimulus-based reversal learning are unique to reversals, and whether and how observed differences depend on reward probability. Here, we used a visual probabilistic discrimination and reversal learning para...
Source: Behavioral Neuroscience - August 30, 2021 Category: Neuroscience Source Type: research
Retrograde amnesia of contextual fear conditioning: Evidence for retrosplenial cortex involvement in configural processing.
It has been suggested that contextual fear conditioning can be supported by either an elemental system, where individual features of the environment are associated with shock, or a configural system, where environmental features are bound together and associated with shock. Although the retrosplenial cortex (RSC) is known to be involved in contextual fear conditioning, it is not clear whether it contributes to the elemental or configural system. To isolate the role of the RSC in contextual fear conditioning, the current experiments examined the influence of RSC lesions on the context preexposure facilitation effect, a proc...
Source: Behavioral Neuroscience - August 30, 2021 Category: Neuroscience Source Type: research
Endogenous hippocampal, not peripheral, estradiol is the key factor affecting the novel object recognition abilities of female rats.
In conclusion, our study strongly demonstrates that hippocampal E2, but not peripheral E2, plays a critical role in NOR ability and that Kalirin-7 may be involved in this mechanism. (PsycInfo Database Record (c) 2021 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - August 16, 2021 Category: Neuroscience Source Type: research
The costs of coping: Different strategies to deal with social defeat stress might come with distinct immunologic, neuroplastic, and oxidative stress consequences in male Wistar rats.
The impact of stress on health and well-being is determined by the ability of an individual to cope with challenges imposed by the stressor. Animals exposed to social defeat stress show different patterns of response during confrontations, leading to distinct stress-induced consequences. Using an established resident–intruder paradigm, we explored the outcomes of adopting active or passive coping strategies during a social defeat protocol over peripheral and central nervous system (CNS) levels of inflammatory cytokines, growth factors, glucocorticoid, and oxidative stress markers in male Wistar rats. Animals that present...
Source: Behavioral Neuroscience - August 12, 2021 Category: Neuroscience Source Type: research
Is there a neuroscience-based, mechanistic rationale for transcranial direct current stimulation as an adjunct treatment for posttraumatic stress disorder?
It is well-known that there is considerable variation in the effectiveness of evidence-based treatments for psychiatric disorders, and a continued need to improve the real-world effectiveness of these treatments. In the last 20+ years the examination of noninvasive brain stimulation techniques for psychiatric treatment has increased dramatically. However, in order to test these techniques for effective therapeutic use, it is critical to understand (a) (what are) the key neural circuits to engage for specific disorders or clusters of symptoms, and (b) (how) can these circuits be reached effectively using neurostimulation? H...
Source: Behavioral Neuroscience - August 2, 2021 Category: Neuroscience Source Type: research
Social behavior in prepubertal neurexin 1α deficient rats: A model of neurodevelopmental disorders.
Loss-of-function mutations in the synaptic protein neurexin1α (NRXN1α) are associated with several neurodevelopmental disorders, including autism spectrum disorder (ASD), schizophrenia, and attention-deficit hyperactivity disorder (ADHD), and many of these disorders are defined by core deficits in social cognition. Mouse models of Nrxn1α deficiency are not amenable to studying aspects of social cognition because, in general, mice do not engage in complex social interactions such as social play or prosocial helping behaviors. Rats, on the contrary, engage in these complex, well-characterized social behaviors. Using the N...
Source: Behavioral Neuroscience - July 29, 2021 Category: Neuroscience Source Type: research
