Flexible and Adaptive Behavioral Strategies: A Personal Journey.

The ground-breaking research of patient H.M. brought to light the importance of the hippocampus for our memories of everyday and special events.

A role for the midbrain reticular formation in delay-based decision making.

In many real-life situations, decisions involve temporal delays between actions and their outcomes. During these intervals, waiting is an active process that requires maintaining motivation and anticipating future rewards. This study aimed to explore the role of the midbrain reticular formation (MRF) in delay-based decision-making.

Flexible decision-making is related to strategy learning, vicarious trial and error, and medial prefrontal rhythms during spatial set-shifting.

Flexible decision-making requires a balance between exploring features of an environment and exploiting prior knowledge. Behavioral flexibility is typically measured by how long it takes subjects to consistently make accurate choices after reward contingencies switch or task rules change. This measure, however, only allows for tracking flexibility across multiple trials, and does not assess the degree of flexibility.

Thriving in neuroscience careers: Three lessons from 12+ years of the BRAINS Program.

The NINDS-funded BRAINS Program for neuroscientists from underrepresented and marginalized groups has positively impacted its participants and the field. We discuss three lessons to advance excellence and diversity: center relationships, provide ongoing engagement, and leverage programmatic expertise.

The medial prefrontal cortex during flexible decisions: Evidence for its role in distinct working memory processes.

During decisions that involve working memory, task-related information must be encoded, maintained across delays, and retrieved. Few studies have attempted to causally disambiguate how different brain structures contribute to each of these components of working memory. In the present study, we used transient optogenetic disruptions of rat medial prefrontal cortex (mPFC) during a serial spatial reversal learning (SSRL) task to test its role in these specific working memory processes.

Connecting Counterspaces and Community Cultural Wealth in a Professional Development Program.

This qualitative study analyzes the relationship between two concepts from critical race theory-counterspaces and community cultural wealth. Counterspaces are supportive, identity-affirming community spaces, while community cultural wealth highlights the importance of the knowledge, skills, and networks used by individuals belonging to marginalized groups to successfully navigate academia. This study investigates the hypothesis that the processes operating within counterspaces serve to strengthen an individual's access to their community cultural wealth.

Hippocampal beta rhythms as a bridge between sensory learning and memory-guided decision-making.

A pillar of systems neuroscience has been the study of neural oscillations. Research into these oscillations spans brain areas, species, and disciplines, giving us common ground for discussing typically disparate fields of neuroscience. In this review, we aim to strengthen the dialog between sensory systems research and learning and memory systems research by examining a 15-40 Hz oscillation known as the beta rhythm.

Response Flexibility: The Role of the Lateral Habenula.

The ability to make appropriate decisions that result in an optimal outcome is critical for survival. This process involves assessing the environment as well as integrating prior knowledge about the environment with information about one's current internal state. There are many neural structures that play critical roles in mediating these processes, but it is not yet known how such information coalesces to influence behavioral output.

Lateral Habenula Beyond Avoidance: Roles in Stress, Memory, and Decision-Making With Implications for Psychiatric Disorders.

In this Perspective review, we highlight some of the less explored aspects of lateral habenula (LHb) function in contextual memory, sleep, and behavioral flexibility. We provide evidence that LHb is well-situated to integrate different internal state and multimodal sensory information from memory-, stress-, motivational-, and reward-related circuits essential for both survival and decision making. We further discuss the impact of early life stress (ELS) on LHb function as an example of stress-induced hyperactivity and dysregulation of neuromodulatory systems within the LHb that promote anhedonia and motivational deficits following ELS.

A Machine Learning Approach for Detecting Vicarious Trial and Error Behaviors.

Vicarious trial and error behaviors (VTEs) indicate periods of indecision during decision-making, and have been proposed as a behavioral marker of deliberation. In order to understand the neural underpinnings of these putative bridges between behavior and neural dynamics, researchers need the ability to readily distinguish VTEs from non-VTEs. Here we utilize a small set of trajectory-based features and standard machine learning classifiers to identify VTEs from non-VTEs for rats performing a spatial delayed alternation task (SDA) on an elevated plus maze.

A selective role for the mPFC during choice and deliberation, but not spatial memory retention over short delays.

Important interactions between memory and decision-making processes are required to maintain high-levels of spatial working memory task performance. Past research reveals that the medial prefrontal cortex (mPFC) and hippocampus (HPC) are both vital structures involved in these processes. Recent evidence suggests that interactions between these two structures are dynamic and task dependent.

Loss of Sensitivity to Rewards by Dopamine Neurons May Underlie Age-Related Increased Probability Discounting.

Normative aging is known to affect how decisions are made in risky situations. Although important individual variability exists, on average, aging is accompanied by greater risk aversion. Here the behavioral and neural mechanisms of greater risk aversion were examined in young and old rats trained on an instrumental probability discounting task.

Selective Functional Interaction Between the Lateral Habenula and Hippocampus During Different Tests of Response Flexibility.

The lateral habenula (LHb) has been shown to play critical roles in a variety of appetitive tasks (e.g., spatial memory and object recognition) that require animals to flexibly respond to changing task conditions.

Transient Input-Specific Neural Plasticity in the Lateral Habenula Facilitates Learning.

In this issue of Neuron, Trusel et al. (2019) demonstrate that circuit-specific plasticity in the lateral habenula is dynamically involved in translating CS-US contingencies into cue-driven avoidance behavior. Disruption of this plasticity prevents learning about CS-US relationships when they are uncertain.

A Novel Role for the Periaqueductal Gray in Consummatory Behavior.

The periaqueductal gray (PAG) has a well-established role in pain processing, autonomic function and behavioral responses to fear. Anatomical work suggests the PAG may mediate food intake and reward processing as it has extensive reciprocal connections within brain circuits that mediate appetitive processes and consummatory behaviors such as prefrontal cortex, hypothalamus, amygdala, parabrachial nucleus (PBN) and ventral tegmental area (Kelley et al., 2005).

Dynamic coding of predatory information between the prelimbic cortex and lateral amygdala in foraging rats.

Predation is considered a major selective pressure in the evolution of fear, but the neurophysiology of predator-induced fear is unknown. We simultaneously recorded lateral amygdala (LA) and prelimbic (PL) area neuronal activities as rats exited a safe nest to search for food in an open space before, during, and after encountering a "predator" robot programmed to surge from afar. Distinct populations of LA neurons transiently increased spiking as rats either advanced or fled the robot, whereas PL neurons showed longer-lasting spike trains that preceded and persisted beyond LA activity.

Control of behavioral flexibility by the lateral habenula.

The ability to rapidly switch behaviors in dynamic environments is fundamental to survival across species. Recognizing when an ongoing behavioral strategy should be replaced by an alternative one requires the integration of a diverse number of cues both internal and external to the organism including hunger, stress, or the presence of reward predictive cues. Increasingly sophisticated behavioral paradigms coupled with state of the art electrophysiological and pharmacological approaches have delineated a brain circuit involved in behavioral flexibility.

The Lateral Habenula and Adaptive Behaviors.

The evolutionarily conserved lateral habenula (LHb) enables dynamic responses to continually changing contexts and environmental conditions. A model is proposed to account for greater mnemonic and contextual control over LHb-mediated response flexibility as vertebrate brains became more complex. The medial prefrontal cortex (mPFC) provides instructions for context-specific responses to LHb, which assesses the extent to which this response information matches the motivation or internal state of the individual.

The BRAINS Program: Transforming Career Development to Advance Diversity and Equity in Neuroscience.

In order to better prepare trainees and advance diversity in neuroscience, career development must move beyond scientific skills. The BRAINS Program's continuous professional development model positively impacts participants' careers by fostering a sense of community and creating a counterspace for critical conversations.

Hippocampal neural activity reflects the economy of choices during goal-directed navigation.

Distinguishing spatial contexts is likely essential for the well-known role of the hippocampus in episodic memory. We studied whether types of hippocampal neural organization thought to underlie context discrimination are impacted by learned economic considerations of choice behavior. Hippocampal place cells and theta activity were recorded as rats performed a maze-based probability discounting task that involved choosing between a small certain reward or a large probabilistic reward.

A framework for understanding and advancing intertemporal choice research using rodent models.

Intertemporal choices are common and consequential to private and public life. Thus, there is considerable interest in understanding the neural basis of intertemporal decision making. In this minireview, we briefly describe conceptual and psychological perspectives on intertemporal choice and then provide a comprehensive evaluation of the neural structures and signals that comprise the underlying cortico-limbic-striatal circuit.

The Lateral Habenula Circuitry: Reward Processing and Cognitive Control.

There has been a growing interest in understanding the role of the lateral habenula (LHb) in reward processing, affect regulation, and goal-directed behaviors. The LHb gets major inputs from the habenula-projecting globus pallidus and the mPFC, sending its efferents to the dopaminergic VTA and SNc, serotonergic dorsal raphe nuclei, and the GABAergic rostromedial tegmental nucleus. Recent studies have made advances in our understanding of the LHb circuit organization, yet the precise mechanisms of its involvement in complex behaviors are largely unknown.

Learning to Thrive: Building Diverse Scientists' Access to Community and Resources through the BRAINS Program.

Broadening the Representation of Academic Investigators in NeuroScience is a National Institutes of Health-funded, national program that addresses challenges to the persistence of diverse early-career neuroscientists. In doing so, BRAINS aims to advance diversity in neuroscience by increasing career advancement and retention of post-PhD, early-career neuroscientists from underrepresented groups (URGs). The comprehensive professional development program is structured to catalyze conversations specific to URGs in neuroscience and explicitly addresses factors known to impact persistence such as a weak sense of belonging to the scientific community, isolation and solo status, inequitable access to resources that impact career success, and marginalization from informal networks and mentoring relationships.

Analysis of morphine-induced changes in the activity of periaqueductal gray neurons in the intact rat.

Microinjection of morphine into the periaqueductal gray (PAG) produces antinociception. In vitro slice recordings indicate that all PAG neurons are sensitive to morphine either by direct inhibition or indirect disinhibition. We tested the hypothesis that all PAG neurons respond to opioids in vivo by examining the extracellular activity of PAG neurons recorded in lightly anesthetized and awake rats.