Cognitive control is believed to arise from task-dependent interactions among networks of brain regions. Although several debilitating neuropsychiatric disorders are characterized by cognitive network dysfunction, the neural circuit mechanisms supporting task-dependent network activity are largely unknown. External and internal task demands elicit opposing responses from key cognitive networks, and claustrum projections target regions associated with both network states. We tested if claustrum supports task-dependent network activity in humans using fMRI during tasks with externally and internally driven demands: working memory ( n = 420) and autobiographical memory ( n = 35). Claustrum activity increased in both tasks. Claustrum exhibited anatomical connectivity with regions representing all implicated networks, and claustrum effective connectivity suggested an excitatory influence on regions in multiple task-associated networks. Task response and connectivity measures differed between the claustrum and regions prominently implicated in directing network states—the anterior insula and pulvinar. These findings establish a role for the claustrum in supporting task-dependent network states subserving cognitive control.

The claustrum is a subcortical nucleus with widespread, reciprocal connections to the cortex and beyond, inspiring many models of its function. Decades of work from rodents provide a foundational understanding of the anatomy and functional organization of the claustrum, which is more recently aided by human functional neuroimaging studies. However, important questions remain with broad functional implications. These center on claustrum anatomical boundaries, functional organization, and the putative expansion of human claustrum connectivity over that predicted by rodent studies alone. Providing new insights by spanning the large rodent-to-human void, a landmark study by Lei and colleagues recently provided thorough molecular and connectivity profiling of the macaque claustrum. Surprising findings of lateralized and expanded claustrum connectivity with cortical and subcortical partners help to explain human functional connectivity data and the discovery of a well-developed organization of the monkey claustrum into overlapping functional sub-domains provides deep insight into claustrum function when considering rodent synaptic connectivity data. Contextualizing these findings, we provide an elaborated model of the function of the claustrum in cognition.

Alcohol use disorder is characterized by persistent drinking in the face of negative consequences. Such inflexible drinking requires dorsolateral striatum fast-spiking interneurons, which comprise roughly 1% of all striatal neurons. How chronic ethanol exposure affects fast-spiking interneuron physiology is poorly understood. We discover in mice that chronic ethanol exposure induced a dramatic loss of GABAergic, but not glutamatergic, synapses onto dorsolateral striatum fast-spiking interneuron somata and proximal dendrites where perineuronal nets, a subdivision of the extracellular matrix, are enriched. We found that chronic ethanol exposure degraded these perineuronal nets and that enzymatically degrading perineuronal nets similarly reduced GABAergic transmission onto dorsolateral striatum fast-spiking interneurons. Modeling the effect of alcohol, we find that silencing extrinsic GABAergic projections to the dorsolateral striatum increased voluntary ethanol consumption. Taken together, these data suggest chronic alcohol exposure remodels perineuronal nets and inhibitory synapses on fast-spiking interneurons to facilitate alcohol drinking.

Pain arises from coordinated activity across distributed brain networks. The claustrum, a thin subcortical nucleus with extensive bidirectional connectivity with the neocortex, has recently emerged as a potential hub in this network. Although historically difficult to isolate due to its thin anatomical structure and proximity to other pain-associated regions, recent advances in neuroimaging and circuit-specific manipulations have revealed new insights into its role in pain. This review synthesizes the evidence from human and animal studies and evaluates the evidential strength of current approaches, ranging from incidental reporting in whole-brain neuroimaging studies to claustrum-targeted imaging, electrophysiology and projection-specific manipulations. The literature suggests that the claustrum contributes to pain not as a primary sensory relay, but as a modulatory and integrative structure influencing various facets of cognition. We have organized these findings into three theory-guided frameworks: (1) sensory filtering of salient stimuli, (2) cognitive network engagement, and (3) offline consolidation of pain-related memory during rest and sleep. In chronic pain, claustrocortical function is altered in ways that map onto each of these frameworks, with rodent models pointing to depressed claustrocingulate output and loss of inhibitory control, and human imaging linking claustrum signals to catastrophizing, expectancy, and altered network recruitment. Taken together, the evidence highlights the claustrum as a promising but incompletely understood node in pain circuitry and underscores the need for more anatomically precise and mechanistically decisive studies to define its contribution to normal and pathological pain states.

Cognitive impairment is a major component of Alcohol Use Disorder. Optimal cognitive performance requires anterior cingulate input activation of the claustrum, a subcortical nucleus that orchestrates cortical activity. Yet the impact of chronic alcohol exposure on the ability for the anterior cingulate cortex to drive activity of claustrum projection neuron subtypes is unknown. In adult male and female mice, we found that the majority of non-burst firing Type 1 claustrum projection neurons did not express the vesicular glutamate transporter 2 (VGLUT2), while the majority of burst firing Type 2 projection neurons were VGLUT2-expressing. Following chronic intermittent vaporized ethanol exposure (CIE), we found that all claustrum neuron types exhibited increased responsivity to anterior cingulate cortex input activation. In Type 1 and VGLUT2-non-expressing neurons this was associated with increased postsynaptic membrane excitability. In contrast, Type 2 and VGLUT2-expressing projection neurons exhibited increased responsivity to anterior cingulate cortex input due to strengthened pre- and post-synaptic transmission mechanisms. Altogether, we uncovered a hyper-excitatory drive of the claustrum by the anterior cingulate cortex following chronic alcohol exposure. The data provide a foundational resource for the complex effects of chronic alcohol exposure on the claustrum, a critical cognitive control nucleus.

Alcohol use disorder (AUD) is characterized by compulsive drinking, which is thought to be mediated by effects of chronic intermittent ethanol exposure on the dorsal striatum, the input nucleus of the basal ganglia. Despite significant efforts to understand the impact of ethanol on the dorsal striatum, the rich diversity of striatal cell types and multitude of ethanol targets expressed by them necessitates an unbiased, discovery-based approach. In this study, we used single-nuclei RNA-sequencing (snRNA-seq; n = 86,715 cells) to examine the impact of chronic intermittent ethanol exposure on the dorsal striatum in C57BL/6 male and female mice. We detected 462 differentially expressed genes at FDR < 0.05, the majority of which were mapped to spiny projection neurons (SPNs), the most prominent cell type in the striatum. Gene co-expression network analysis and functional annotation of differentially expressed genes revealed down-regulation of postsynaptic intracellular signaling cascades in SPNs. Inflammation-related genes were down-regulated across many neuronal and non-neuronal cell types. Gene set enrichment analyses also pointed to altered states of rare cell types, including the induction of angiogenesis-related genes in vascular cells. A gene module down-regulated specifically in canonical SPNs was enriched for calcium-signaling genes and components of glutamatergic synapses, as well as for genes associated with genetic risk for AUD. Genetic perturbations of six of this module's hub genes - Foxp1, Bcl11b, Pde10a, Rarb, Rgs9, and Itgr1 - had causal effects on its expression in the mouse striatum and/or on the broader set of differentially expressed genes in alcohol-exposed mice. These data provide important clues as to the impact of ethanol on striatal biology and provide a key resource for future investigation.

Through its widespread reciprocal connections with the cerebral cortex, the claustrum is implicated in sleep and waking cortical network states. Yet, basic knowledge of neuromodulation in this structure is lacking. The claustrum is richly innervated by serotonergic fibers, expresses serotonin receptors, and is suggested to play a role in the ability of psilocybin, which is metabolized to the non-specific serotonin receptor agonist psilocin, to disrupt cortex-wide network states. We therefore addressed the possible role of serotonin, and the classic psychedelic psilocybin, in modulating cortical signaling through the claustrum. We show that serotonin activates 5-HT1B receptors on anterior cingulate cortex inputs - a primary driver of claustrum activity - to suppress signaling to parietal association cortex-projecting claustrum neurons. Additionally, we demonstrate that psilocybin injection also activates anterior cingulate cortex presynaptic 5-HT1B receptors to suppress cortical signaling through the claustrum. Thus, serotonin, via 5-HT1B, may provide gain-control of cortical input to the claustrum, a mechanism that may be directly targeted by psilocybin to modulate downstream cortical network states.

Cognitive control is believed to arise from interactions among multiple brain networks depending on task demands. Although several debilitating neuropsychiatric disorders are characterized by cognitive network dysfunction, the neural circuit mechanisms supporting task-dependent network activation are largely unknown. Because the claustrum possesses widespread connections with cortex and can synchronize distant cortical regions, we tested whether the claustrum activates task-dependent network states using fMRI during working memory (n = 420) and autobiographical memory (n = 35), tasks which elicit opposing responses from key cognitive control networks. In both tasks, the claustrum exhibited increased activity and excitatory influence on task-associated cognitive control network nodes, with corroborating underlying structural connectivity. The claustrum also displayed stronger excitatory effective connectivity during task performance and greater structural connectivity with task-related network nodes than regions prominently implicated in directing network states-the anterior insula and pulvinar. These findings establish a role for the claustrum in initiating network states for cognitive control.

The two main cell types in the striatum, dopamine receptor 1 and adenosine receptor 2a spiny projection neurons (D1-SPNs and A2A-SPNs), have distinct roles in regulating motor- and reward-related behaviors. Cre-selective CRISPR-dCas9 systems allow for cell-type specific, epigenomic-based manipulation of gene expression with gene-specific single guide RNAs (sgRNAs) and have potential to elucidate molecular mechanisms underlying striatal subtype mediated behaviors. Conditional transgenic Rosa26:LSL-dCas9-p300 mice were recently generated to allow for robust expression of dCas9-p300 expression with Cre-driven cell-type specificity. This system utilizes p300, a histone acetyltransferase which regulates gene expression by unwinding chromatin and making that region of the genome more accessible for transcription. Rosa26-LSL-dCas9-p300 mice were paired with Drd1-Cre and Ador2a-Cre mice to generate Drd1-Cre:dCas9-p300 and Ador2a-Cre:dCas9-p300 mouse lines and underwent behavioral phenotyping when sgRNAs were not present. Both Drd1-Cre:dCas9-p300 and Ador2a-Cre:dCas9-p300 have cell-type-specific expression of spCas9 mRNA. Baseline behavioral assessments revealed that, under a sgRNA absent nontargeted state, Drd1-Cre:dCas9-p300 mice display repetitive spinning behavior, hyperlocomotion, and enhanced acquisition of reward learning in comparison with all genotypic littermates. In contrast, Ador2a-Cre:dCas9-p300 do not exhibit any changes in behavior in comparison with their littermates. Electrophysiological recordings of dorsal striatum D1-SPNs revealed that Drd1-Cre:dCas9-p300 mice have increased input resistance and increased spontaneous excitatory postsynaptic current amplitude, together suggesting greater excitatory drive of D1-SPNs. Overall, these data demonstrate the necessity to validate CRISPR-dCas9 lines for research investigations. Additionally, the Drd1-Cre:dCas9-p300 line has the potential to be used to study underlying mechanisms of stereotypy and reward learning.

Dysregulation of normal reward processing via psychological stress contributes to the development of psychiatric disorders. Estrogen is involved in reward processing in females, but this effect has not been well studied in males despite the abundant conversion of androgens to estrogens in the male brain. Here, we used a combination of genetic deletions, behavioral assays, pharmacology, circuit dissection, electrophysiology, in vivo fiber photometry, and optogenetics/chemogenetics to determine the role of the most prevalent and potent estrogen, 17β-estradiol, in male stress-induced reward processing dysfunction. We found that absence of estrogen receptor (ER) β renders male but not female mice susceptible to stress-induced maladaptive reward-processing behaviors. We demonstrated that activation of ERβ-projecting neurons from the basolateral amygdala to nucleus accumbens induced rewarding effects in male, but not female mice. Moreover, we show that the activity of ERβ-expressing neurons projecting from the basolateral amygdala to nucleus accumbens is reduced in hypogonadal male mice subjected to stress, while activation of this circuit reverses stress-induced maladaptive reward processing behaviors and inhibition induces stress susceptibility. We identified that absence of estradiol, but not testosterone per se, underlies susceptibility to stress-mediated dysfunction of rewarding behaviors and that brain-selective delivery of estradiol and intra-basolateral amygdala administration of an ERβ-specific agonist prevent maladaptive reward-processing behaviors in hypogonadal male mice. These findings delineate an estrogen-based mechanism underlying stress susceptibility and provide a novel therapeutic strategy for the treatment of reward-related disorders associated with hypogonadal conditions.

Cognitive control, the ability to manage information during purposeful actions, is crucial for everyday functioning and can become impaired in a variety of neuropsychiatric disorders. The claustrum, a subcortical brain structure with widespread cortical connections, is proposed to activate with cognitive load to support cortical network demands across cognitive domains. With this model in mind, we examined the claustrum signal within a dataset (n = 55) that includes functional MRI (fMRI) of healthy participants engaged in four well-established cognitive control tasks: the Stroop task, AX-continuous performance task (AX-CPT), cued task-switching and Sternberg working memory task. Bilateral claustrum activation was observed during certain conditions and trial phases of all four tasks, particularly during times of increased cognitive demand, and coinciding with task-positive cortical network activations. These findings demonstrate claustrum activation across multiple cognitive control tasks and potentially pave the way for new insights into how cognitive processes are compromised in neuropsychiatric disorders.

Aberrant cognitive network activity and cognitive deficits are established features of chronic pain. However, the nature of cognitive network alterations associated with chronic pain and their underlying mechanisms require elucidation. Here, we report that the claustrum, a subcortical nucleus implicated in cognitive network modulation, is activated by acute painful stimulation and pain-predictive cues in healthy participants. Moreover, we discover pathological activity of the claustrum and a region near the posterior inferior frontal sulcus of the right dorsolateral prefrontal cortex (piDLPFC) in migraine patients during acute pain and cognitive task performance. Dynamic causal modeling suggests a directional influence of the claustrum on activity in this piDLPFC region, and diffusion weighted imaging verifies their structural connectivity. These findings advance understanding of claustrum function during acute pain and provide evidence of a possible circuit mechanism driving cognitive impairments in chronic pain.

Neuronal computation is metabolically expensive and relies on the timely delivery of energy substrates via tightly controlled blood flow to prevent energetic deficits. The range of mechanisms responsible for this coupling of neural activity to blood flow are collectively termed ‘neurovascular coupling’ (NVC). These NVC mechanisms are typically assumed to be invariant and the possibility that they may be plastic, allowing reshaping of energy delivery according to ever-shifting neuronal metabolic needs, has not been considered. We present evidence that neuronal activity resculpts blood flow control mechanisms inherent to the endothelium, which forms the inner lining of all blood vessels, through a process we refer to as vascular signalling plasticity (VSP). Using an environmental enrichment paradigm, we find that housing mice in an environment that increases input to the barrel cortex drives profound synaptic plasticity within this network. This is accompanied by a remarkable resculpting of local vascular reactivity, augmenting the efficacy of mechanisms that signal for an increase in blood flow. This increase in sensitivity manifests as an increase red blood cell flux to capillary stimulation with extracellular K+, which activates strong inward rectifier K+ (Kir2.1) channel-dependent capillary-to-arteriole electrical signalling to elicit hyperemia. To support this augmentation, we find that VSP induces a ~70% increase in the density of Kir2.1 channels in endothelial cells membranes which is underlain by transcriptional and translational changes in capillary ECs. Using an ex vivo capillary-arteriole preparation, we demonstrate that this increase in membrane Kir2.1 channels translates into a profound shift in the sensitivity of capillaries to K+ stimulation to evoke upstream arteriolar dilation. Together, these results suggest that increasing neuronal energy consumption leads to a profound potentiation of the retrograde hyperpolarization generated by the endothelium during activity, enhancing upstream dilation at the penetrating arteriole and augmenting blood delivery to match enhanced local needs. Our data thus recast the capillary bed as a plastic, brain-wide, neural activity sensing network that is modulated at the molecular level by local neural input. This allows fine-tuning of existing blood delivery mechanisms to meet continually fluctuating neural energy needs. VSP represents a novel facet of brain plasticity that may be utilised by various physiological processes and may be disrupted in aging and in the broad range of brain pathologies that have a vascular component. Support for this work was provided by the NIH National Institute on Aging and National Institute of Neurological Disorders and Stroke (1R01AG066645, 5R01NS115401 [PI: S. Sakadžić], and 1DP2NS121347-01, to T.A.L), the American Heart Association (Awards 17SDG33670237 and 19IPLOI34660108 to T.A.L) and an NIH S10 grant (S10 OD026698, to University of Maryland School of Medicine CIBR Core Confocal Facility). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Impulsive choice has enduring trait-like characteristics and is defined by preference for small immediate rewards over larger delayed ones. Importantly, it is a determining factor in the development and persistence of substance use disorder (SUD). Emerging evidence from human and animal studies suggests frontal cortical regions exert influence over striatal reward processing areas during decision-making in impulsive choice or delay discounting (DD) tasks. The goal of this study was to examine how these circuits are involved in decision-making in animals with defined trait impulsivity. To this end, we trained adolescent male rats to stable behavior on a DD procedure and then re-trained them in adulthood to assess trait-like, conserved impulsive choice across development. We then used chemogenetic tools to selectively and reversibly target corticostriatal projections during performance of the DD task. The prelimbic region of the medial prefrontal cortex (mPFC) was injected with a viral vector expressing inhibitory designer receptors exclusively activated by designer drugs (Gi-DREADD), and then mPFC projections to the nucleus accumbens core (NAc) were selectively suppressed by intra-NAc administration of the Gi-DREADD actuator clozapine-n-oxide (CNO). Inactivation of the mPFC-NAc projection elicited a robust increase in impulsive choice in rats with lower vs. higher baseline impulsivity. This demonstrates a fundamental role for mPFC afferents to the NAc during choice impulsivity and suggests that maladaptive hypofrontality may underlie decreased executive control in animals with higher levels of choice impulsivity. Results such as these may have important implications for the pathophysiology and treatment of impulse control, SUDs, and related psychiatric disorders.

Parvalbumin-expressing dorsal striatal fast-spiking interneurons, comprising ∼1% of the total dorsal striatal neuronal population, are necessary for the expression of compulsive-like ethanol consumption mice. Fast-spiking interneurons are driven to fire by glutamatergic inputs derived primarily from the cortex. However, these neurons also receive substantial GABAergic input from two sources: the globus pallidus and the reticular nucleus of the thalamus. How ethanol modulates inhibitory input onto fast-spiking neurons is unclear and, more broadly, alcohol effects on GABAergic synaptic transmission onto GABAergic interneurons are understudied. Examining this, we found that acute bath application of ethanol (50 mM) potentiated GABAergic transmission from both the globus pallidus and the reticular nucleus of the thalamus onto fast-spiking interneurons in mouse of both sexes. This ethanol-induced potentiation required postsynaptic calcium and was not accompanied by a sustained change in presynaptic GABA release probability. Examining whether this ethanol effect persisted following chronic intermittent ethanol exposure, we found attenuated acute-ethanol potentiation of GABAergic transmission from both the globus pallidus and the reticular nucleus of the thalamus onto striatal fast-spiking interneurons. These data underscore the impact of ethanol on GABAergic signaling in the dorsal striatum and support the notion that ethanol may disinhibit the dorsolateral striatum.

The striatum is a subcortical structure that serves as the primary input nucleus of the basal ganglia. Through its diverse arrangement of afferent and efferent connections, the striatum regulates the expression of actions by integrating motor commands with cognitive, motivational, and emotional input (Haber, 2016). By merging internal value with external cues, the striatum learns which actions, and in which context, result in the acquisition of a reward and reinforces those actions to guide future reward-driven behavior. If the reward being sought is a drug of abuse, the striatum pathologically promotes actions that lead to acquisition of the substance. Consider the process of drinking a few beers after a stressful week of work. Execution of this behavior requires the selection of a motor plan motivated by an internal drive (e.g., to reduce stress) and the integration of the reward history of that motor action (e.g., drinking previously was rewarding). Once this motor program is learned, through repeated execution and reinforcement, this behavior becomes engrained in striatal circuits and can be elicited almost automatically by sensory cues in the environment—even in the face of known negative consequences (e.g., drinking previously led to poor work performance). As such, the striatum plays a fundamental role in the decisions and actions we make every day, and by extension how we define ourselves through those actions.

Generating animal models for individual patients within clinically-useful timeframes holds great potential toward enabling personalized medicine approaches for genetic epilepsies. The ability to rapidly incorporate patient-specific genomic variants into model animals recapitulating elements of the patient's clinical manifestations would enable applications ranging from validation and characterization of pathogenic variants to personalized models for tailoring pharmacotherapy to individual patients. Here, we demonstrate generation of an animal model of an individual epilepsy patient with an ultra-rare variant of the NMDA receptor subunit GRIN2A, without the need for germline transmission and breeding. Using in utero prime editing in the brain of wild-type mice, our approach yielded high in vivo editing precision and induced frequent, spontaneous seizures which mirrored specific elements of the patient's clinical presentation. Leveraging the speed and versatility of this approach, we introduce PegAssist, a generalizable workflow to generate bedside-to-bench animal models of individual patients within weeks. The capability to produce individualized animal models rapidly and cost-effectively will reduce barriers to access for precision medicine, and will accelerate drug development by offering versatile in vivo platforms to identify compounds with efficacy against rare neurological conditions.

The dorsal striatum (DS) mediates the selection of actions for reward acquisition necessary for survival. Striatal pathology contributes to several neuropsychiatric conditions, including aberrant selection of actions for specific rewards in addiction. A major source of glutamate driving striatal activity is the rostral intralaminar nuclei (rILN) of the thalamus. Yet, the information that is relayed to the striatum to support action selection is unknown. Here, we discovered that rILN neurons projecting to the DS are innervated by a range of cortical and subcortical afferents and that rILN→DS neurons stably signaled at two time points in mice performing an action sequence task reinforced by sucrose reward: action initiation and reward acquisition. In vivo activation of this pathway increased the number of successful trials, whereas inhibition decreased the number of successful trials. These findings illuminate a role for the rostral intralaminar nuclear complex in reinforcing actions.