An ace in the hole? Opportunities and limits of using mice to understand schizophrenia neurobiology

In applying model organisms to study the neurobiology of mental disorders, rodents offer unique potential for probing, with high spatiotemporal resolution, the neural and molecular mechanisms underlying behavior in a mammalian system. Furthermore, investigators can wield exceptional power to manipulate genes, molecules, and circuits in mice to pin down causal relationships. While these advantages have allowed us to understand much more deeply than ever before the brain mechanisms regulating complex behaviors, the impact of rodent models on developing therapeutic strategies for psychiatric disorders has remained thus far limited. Herein, we will discuss the opportunities and limits of using mouse models in the context of schizophrenia, a complex psychiatric disorder with strong genetic basis that poses various unmet clinical needs calling out for basic science research. We review approaches for employing behavioral, genetic, and circuit-based methods in rodents to inform schizophrenia symptomatology, pathophysiology, and, ultimately, treatment.

Resting-State Functional MRI Reveals Altered Seed-Based Connectivity in Diabetic Osteoporosis Patients

Background

Diabetic osteoporosis (DOP) can cause abnormal brain neural activity, but its mechanism is still unclear. This study aims to further explore the abnormal functional connectivity between different brain regions based on the team's previous research.

Methods

Resting-state functional magnetic resonance imaging (rs-fMRI) data were obtained from 14 participants diagnosed with type 2 diabetes mellitus (T2DM) and osteoporosis. For comparison, data from 13 T2DM patients without osteoporosis were analyzed. The seed regions for functional connectivity (FC) analysis were chosen according to brain areas previously reported to exhibit abnormal regional homogeneity (ReHo).

Results

DOP patients exhibited significantly decreased BMD, T-scores, MoCA scores, and osteocalcin (OC) levels compared to controls (p<0.05). FC analysis revealed: 1) Reduced connectivity between the left middle temporal gyrus (increased ReHo) and middle occipital gyrus; 2) Enhanced connectivity between the right angular gyrus (increased ReHo) and left Rolandic operculum; 3) Weakened the left precuneus (increased ReHo) and right superior/left middle frontal gyri. These alterations correlated with deficits in visual processing, working memory, and executive function.

Conclusion

Distinct FC reorganization in DOP patients reflects synergistic effects of metabolic and skeletal pathologies on neural networks, potentially mediating cognitive decline through visual pathway disruption and prefrontal-default mode network decoupling. The findings highlight neuroimaging biomarkers for metabolic bone disease-related cognitive disorders.

Intelligence, brain structure, dendrites, and genes: Genetic, epigenetic and the underlying of the quadruple helix complexity

Intelligence can be referred to as the mental ability to learn, comprehend abstract concepts, and solve complex problems. Twin and adoption studies have provided insights into the influence of the familial environment and highlighted the importance of heritability in the development of cognition. Detecting the relative contribution of brain areas, neuronal structures, and connectomes has brought some understanding on how various brain areas, white/gray matter structures and neuronal connectivity process information and contribute to intelligence. Using histological, anatomical, electrophysiological, neuropsychological, neuro-imaging and molecular biology methods, several key concepts have emerged: 1) the parietofrontal-hippocampal integrations probably constitute a substrate for smart behavior, 2) neuronal activity results in structural plasticity of dendritic branches responsible for information transfer, critical for learning and memory, 3) intelligent people process information efficiently, 4) the environment triggers mnemonic epigenomic programs (via dynamic regulation of chromatin accessibility, DNA methylation, loop interruption/formation and histone modification) conferring cognitive phenotypes throughout life, and 5) single/double DNA breaks are prominent in human brain disorders associated with cognitive impairment including Alzheimer's disease and schizophrenia. Along with these observations, molecular/cellular/biological studies have identified sets of specific genes associated with higher scores on intelligence tests. Interestingly, many of these genes are associated with dendritogenesis. Because dendrite structure/function is involved in cognition, the control of dendrite genesis/maintenance may be critical for understanding the landscape of general/specific cognitive ability and new pathways for therapeutic approaches.

Astrocyte Dysfunctions in Obsessive Compulsive Disorder: Rethinking Neurobiology and Therapeutic Targets

Obsessive-compulsive disorder (OCD) has long been conceptualized as a neuron-centric disorder of cortico-striato-thalamo-cortical (CSTC) circuit dysregulation. However, a growing body of evidence is now reframing this narrative, placing astrocytes-once relegated to passive support roles-at the center of OCD pathophysiology. Astrocytes are critical regulators of glutamate and GABA homeostasis, calcium signaling, and synaptic plasticity, all of which are disrupted in OCD. Recent high-resolution molecular and proteomic studies reveal that specific astrocyte subpopulations, including Crym-positive astrocytes, directly shape excitatory/inhibitory balance and control perseverative behaviors by modulating presynaptic inputs from the orbitofrontal cortex. Disruptions in astrocytic neurotransmitter clearance and dopamine metabolism amplify CSTC circuit hyperactivity and reinforce compulsions. This review reframes OCD as a disorder of neuro-glial dysfunctions, proposing that targeting astrocytic signaling, metabolism, and structural plasticity may unlock transformative therapeutic strategies. By integrating human and animal data, we advocate for a glial-centric model of OCD that not only enhances mechanistic understanding but also opens new frontiers for precision treatment.

Somatostatin-expressing Neurons in the Medial Prefrontal Cortex Promote Sevoflurane Anesthesia in Mice

BACKGROUND

The medial prefrontal cortex plays a crucial role in regulating consciousness. However, the specific functions of its excitatory and inhibitory networks during anesthesia remain uncertain. Here, the authors explored the hypothesis that somatostatin interneurons in the medial prefrontal cortex enhance the effects of sevoflurane anesthesia by increasing γ-aminobutyric acid (GABA) transmission to pyramidal neurons.

METHODS

Electroencephalography was utilized to reflect the depth of anesthesia. Immunostaining and fiber photometry were employed to assess neuronal activities and GABA delivery. The regulation of neuronal activity was achieved by chemogenetics and optogenetics.

RESULTS

The expression of c-Fos was increased in somatostatin neurons of the medial prefrontal cortex during sevoflurane anesthesia (air vs. sevoflurane: 26.4 ± 6.5% vs. 48 ± 6.2%; P = 0.0007; n = 5 mice). Chemogenetic inhibition or activation of somatostatin neurons in the medial prefrontal cortex reduced (from 84 ± 24 s to 51 ± 18 s; P = 0.008; n = 7 mice) or prolonged (from 97 ± 31 s to 140 ± 30 s; P = 0.006; n = 7 mice) the sevoflurane anesthesia recovery time. Increased GABA input to pyramidal neurons in the medial prefrontal cortex precedes sevoflurane-induced loss of consciousness (baseline vs . pre-loss of the righting reflex: from 0.46 ± 0.57% to 2.25 ± 1.42%; P = 0.031; n = 10 mice). Activation of somatostatin neurons in the medial prefrontal cortex leads to a significant reduction in calcium signals within local pyramidal neurons (baseline vs . 20 Hz stimulation: from -0.14 ± 0.52% to -10.08 ± 4.44%; P = 0.002; n = 10 mice). Additionally,GABA input on pyramidal neurons increased (baseline vs . 20 Hz stimulation: from -0.001 ± 0.001% to 0.28 ± 0.03%; P = 0.002; n = 7 mice) in a time-locked manner. Chemogenetic inhibition of pyramidal neurons prolonged the recovery from sevoflurane anesthesia in mice (from 101 ± 46 s to 136 ± 54 s; P = 0.017; n = 19 mice).

CONCLUSIONS

Cortical somatostatin neurons may inhibit local pyramidal neurons by enhancing GABA transmission, which increases the effectiveness of sevoflurane anesthesia.

Functional-based parcellation of the mouse prefrontal cortex for network perturbation analysis

The prefrontal cortex (PFC) is a brain region involved in higher-order cognitive processes such as attention, emotional regulation, and social behavior. However, the delineation of distinct subdivisions within the mouse PFC and their contributions to the broader brain network function remain debated. This study utilizes resting-state functional magnetic resonance imaging (MRI) from a cohort of 100 C57BL/6J wild-type mice to derive the functional connectivity (FC)-based parcellation of the mouse PFC with voxel resolution. Our findings reveal clusters that deviate from the established anatomical subdivisions within the cingulate and prelimbic areas while aligning in infralimbic and orbital cortices. Upon the chemogenetic perturbation of one of the clusters, FC perturbations occur only within the functional network linked to the targeted cluster and do not spread to neighboring anatomical areas or functional clusters. We propose FC-based parcellation as a valuable approach for tracking the site of activation and network impact of neurostimulation strategies.

Effects of different AI-driven Chatbot feedback on learning outcomes and brain activity

Artificial intelligence (AI) driven chatbots provide instant feedback to support learning. Yet, the impacts of different feedback types on behavior and brain activation remain underexplored. We investigated how metacognitive, affective, and neutral feedback from an educational chatbot affected learning outcomes and brain activity using functional near-infrared spectroscopy. Students receiving metacognitive feedback showed higher transfer scores, greater metacognitive sensitivity, and increased brain activation in the frontopolar area and middle temporal gyrus compared to other feedback types. Such activation correlated with metacognitive sensitivity. Students receiving affective feedback showed better retention scores than those receiving neutral feedback, along with higher activation in the supramarginal gyrus. Students receiving neutral feedback exhibited higher activation in the dorsolateral prefrontal cortex than other feedback types. The machine learning model identified key brain regions that predicted transfer scores. These findings underscore the potential of diverse feedback types in enhancing learning via human-chatbot interaction, and provide neurophysiological signatures.

Direct comparisons of neural activity during placebo analgesia and nocebo hyperalgesia between humans and rats

Placebo analgesia and nocebo hyperalgesia can profoundly alter pain perception, offering critical implications for pain management. While animal models are increasingly used to explore the underlying mechanisms of these phenomena, it remains unclear whether animals experience placebo and nocebo effects in a manner comparable to humans or whether the associated neurobiological pathways are conserved across species. In this study, we introduce a novel framework for comparing brain activity between humans and rodents during placebo analgesia and nocebo hyperalgesia. Using c-Fos immunohistochemistry in rats and fMRI in humans, we examined neural activity in 70 pain-related brain regions, identifying both conserved and species-specific connectivity changes. Functional connectivity analysis, refined by pruning connections based on known anatomical pathways, revealed significant overlap in key regions, including the amygdala, anterior cingulate cortex, and nucleus accumbens, highlighting conserved circuits driving placebo and nocebo responses. This cross-species methodology offers a powerful new approach for investigating the neurobiology of pain modulation, bridging the gap between animal models and human studies. Identifying these common connections validates the use of animal models and enables preclinical researchers to focus on circuits that are conserved across species, ensuring greater translational relevance when developing new and effective treatments for pain conditions.

Understanding disrupted motivation in Parkinson's disease through a value-based decision-making lens

Neurobehavioural disturbances such as loss of motivation have profound effects on the lives of many people living with Parkinson's disease (PD), as well as other brain disorders. The field of decision-making neuroscience, underpinned by a plethora of work across species, provides an important framework within which to investigate apathy in clinical populations. Here we review how changes in a number of different processes underlying value-based decision making may lead to the common phenotype of apathy in PD. The application of computational models to probe both behaviour and neurophysiology show promise in elucidating these cognitive processes crucial for motivated behaviour. However, observations from the clinical management of PD demand an expanded view of this relationship, which we aim to delineate. Ultimately, effective treatment of apathy may depend on identifying the pattern in which decision making and related mechanisms have been disrupted in individuals living with PD.

Biomarker identification in bipolar disorder

Bipolar disorder (BD) is a severe psychiatric condition whose pathophysiology is complex and multifactorial. Genetic, environmental and social risk factors play a role in its development as well as in its progressive course. Research is currently focusing on the identification of the biological basis underlying these processes in order to suggest novel biomarkers capable to predict BD etiopathogenesis and staging. Staging has been recognized as of great value for the treatment and management of many illnesses and might also be suitable for mental health issues, particularly in disorders like BD, which progress from an initial mild phase to a more severe and thus difficult-to-treat situation. Thus, it would be of great help the characterization of to suggest better treatment requirements and improve prognosis across the different stages of the illness. Here, we summarize current research on the biological hypotheses of BD and the biomarkers associated with its progression, reviewing clinical studies available in the literature.

Development of the rodent prefrontal cortex: circuit formation, plasticity, and impacts of early life stress

The prefrontal cortex (PFC), located at the anterior region of the cerebral cortex, is a multimodal association cortex essential for higher-order brain functions, including decision-making, attentional control, memory processing, and regulation of social behavior. Structural, circuit-level, and functional abnormalities in the PFC are often associated with neurodevelopmental disorders. Here, we review recent findings on the postnatal development of the PFC, with a particular emphasis on rodent studies, to elucidate how its structural and circuit properties are established during critical developmental windows and how these processes influence adult behaviors. Recent evidence also highlights the lasting effects of early life stress on the PFC structure, connectivity, and function. We explore potential mechanisms underlying these stress-induced alterations, with a focus on epigenetic regulation and its implications for PFC maturation and neurodevelopmental disorders. By integrating these insights, this review provides an overview of the developmental processes shaping the PFC and their implications for brain health and disease.

Taurine, an essential amino acid, attenuates rotenone-induced Parkinson's disease in rats by inhibiting alpha-synuclein aggregation and augmenting dopamine release

Reducing antioxidant levels exacerbates the generation of reactive oxygen/nitrogen species, leading to alpha-synuclein aggregation and the degeneration of dopaminergic neurons. These play a key role in the onset of Parkinson's disease (PD), for which effective treatment remains elusive. This study examined the neuroprotective effects of taurine, an essential β-amino acid with antioxidant and antiinflammation properties, in Swiss male mice exposed to rotenone-induced PD. Mice (20-25 g) were grouped into seven groups (n = 9) and treated with taurine alone (5, 10 and 20 mg/kg, p.o) or levodopa (10 mg/kg, p.o) for 28 consecutive days following intraperitoneal co-administration of rotenone (1.5 mg/kg, in 5 % dimethylsulfoxide) for 14 alternate days. Open-field, rota-rod and hanging-wire motor performance and coordination tests were conducted on days 26-28. Oxidative stress and neuroinflammatory markers; levels of acetylcholinesterase enzyme activity, dopamine, and alpha-synuclein were assayed in the striatal and prefrontal-cortical regions alongside histological examinations. Rotenone significantly reduced latency to fall and akinesia-like behavior with several slip/error relative to vehicle groups. Taurine increased the latency to fall, notably improving motor coordination, locomotor deficit, and neuromuscular competence. Also, rotenone significantly increased malondialdehyde and nitrite; while decreasing acetylcholinesterase activity, glutathione, catalase, superoxide-dismutase, and glutathione-S-transferase levels in the striatum and prefrontal-cortex respectively, which were attenuated by taurine. Taurine increased dopamine levels in the striatum and prefrontal cortex dose-independently. Like carbidopa, taurine decreased alpha-synuclein, tumor-necrosis factor-α and interleukin-6 levels in the striatum and prefrontal-cortex. Additionally, taurine-reversed rotenone-induced neurodegeneration in the striatum and prefrontal cortex indicates neuroprotective function. Conclusively, taurine attenuates rotenone-induced PD-like behavior by enhancing the brain's antioxidant system, inhibiting pro-inflammatory cytokine release, reducing α-synuclein formation, and augmenting dopaminergic release in mice's brains.

The emergent property of inhibitory control: implications of intermittent network-based fNIRS neurofeedback training

Background

Studies have shown that inhibitory control is supported by frontal cortex and small-world brain networks. However, it remains unclear how regulating the topology changes the inhibitory control. We investigated the effects of small-worldness upregulation training on resting-state networks via fNIRS neurofeedback training, which will contribute to a deeper insight of inhibitory control.

Methods

A five-day training session was used to regulate the small-worldness of the frontal cortex, and the color-word Stroop task was tested before and after training. Fifty healthy adults were recruited and randomly assigned to the sham feedback group (sham group), or intermittent fNIRS-based brain network feedback group (fNIRS-NF group). On the basis of the exclusion of incomplete data, 45 valid data sets were retained and analyzed (sham: 21, fNIRS-NF: 24).

Results

Training increased resting-state small-worldness and improved Stroop task performance, with a significant correlation between these changes (r = -0.32, p = 0.032). The fNIRS-NF group exhibited reduced hemodynamic activation (βvalue decreased, indicating lower cognitive load) during posttest and follow-up. Notably, the right dorsolateral prefrontal cortex (dlPFC) showed greater intra-regional connectivity increases than the left dlPFC, suggesting asymmetric plasticity.

Conclusion

Intermittent fNIRS neurofeedback effectively modulates resting-state small-world networks and enhances inhibitory control, with effects sustained for at least one week. These findings highlight small-worldness as a novel target for cognitive interventions.

Different Sides of Craniotomy for Anteriorly Superiorly Projecting Anterior Communicating Artery Aneurysm Clipping: Outcome and Long-Term Cognitive Function: A Single-Center Retrospective Study

BACKGROUND

We explored the impact of various craniotomy approaches on the outcomes and long-term cognitive function of microsurgical clipping for superiorly projecting anterior communicating artery (ACoA) aneurysms.

METHODS

We retrospectively analyzed 127 superiorly projected ACoA aneurysms that underwent microsurgical clipping between January 2014 and January 2022. Patients were categorized into 2 types: type 1 (n = 70), characterized by the posterior positioning of the ipsilateral A2 segment (open A2 plane side); and type 2 (n = 57), characterized by the anterior positioning of the ipsilateral A2 segment (closed A2 plane side). The analysis focused on clinical outcomes (modified Rankin Scale score) and long-term cognitive function (Montreal Cognitive Assessment).

RESULTS

No significant differences in initial attributes were observed between the 2 groups. No differences were found in modified Rankin Scale score (P = 0.483), cognitive impairment (P = 0.190), or severe cognitive impairment (P = 0.332) between the 2 groups. Furthermore, no significant differences in delayed cerebral ischemia (P = 0.852), delayed bleeding (P = 0.912), or intraoperative rupture (P = 0.141) was found between the 2 groups. However, the occurrence of Montreal Cognitive Assessment subcategories of postponed memory items (P < 0.05) and conceptualization items (P < 0.05) demonstrated a significant decrease on the accessible A2 plane side during a shorter operative time (P = 0.03) and reduced gyrus rectus aspiration frequency (P < 0.001).

CONCLUSIONS

The anterior position of the A2 segment can offer better visualization of the aneurysm dome, bilateral A2, and AcoA, leading to reduced operative time and gyrus rectus aspiration frequency, potentially enhancing long-term cognitive function.

Illuminating the impact of stress: In vivo approaches to track stress-related neural adaptations

Stressful experiences can affect both daily life and long-term health outcomes in a variety of ways. Acute challenges may be adaptive, promoting arousal and enhancing memory and cognitive function. Importantly, however, chronic stress dysregulates the body's physiological regulatory mechanisms consisting of complex hormone interactions throughout the peripheral and central nervous systems. This disrupted signaling consequently alters the balance of synapse formation, maturation and pruning, processes which regulate neural communication, plasticity, learning, cognitive flexibility and adaptive behaviors - hallmarks of a healthy, functional brain. The chronically stressed brain state, therefore, is one which may be uniquely vulnerable. To understand the development of this state, how it is sustained and how behavior and neural function are transiently or indelibly impacted by it, we can turn to a number of advanced approaches in animal models which offer unprecedented insights. This has been the aim of my recent work within the field and the goal of my new independent research program. To achieve this, I have employed methods to uncover how key brain circuits integrate information to support motivated behaviors, how stress impacts their ability to perform this process and how best to operationalize behavioral readouts. Here I present an overview of research contributions that I find most meaningful for advancing our understanding of the impact of stress and propose new avenues which will guide my own framework to address the salient outstanding questions within the field.

Heterogeneity of Layer 1 Interneurons in the Mouse Medial Prefrontal Cortex

Cortical Layer 1 (L1) acts as a critical relay for processing long-range inputs. GABAergic inhibitory interneurons (INs) in this layer (Layer 1 interneurons [L1INs]) function as inhibitory gates, regulating these inputs and modulating the activity of deeper cortical layers. However, their characteristics and circuits in the medial prefrontal cortex (mPFC) remain poorly understood. Using biocytin labeling, we identified three distinct morphological types of mPFC L1INs: neurogliaform cells (NGCs), elongated NGCs (eNGCs), and single-bouquet cell-like (SBC-like) cells. Whole-cell recordings revealed distinct firing patterns across these subtypes: NGCs and eNGCs predominantly exhibited late-spiking (LS) patterns, and SBC-like cells displayed a higher prevalence of non-LS (NLS) patterns. We observed both electrical and chemical connections among mPFC L1INs. Optogenetic activation of NDNF+ L1INs demonstrated broad inhibitory effects on deeper layer neurons. The strength of inhibition on pyramidal neurons (PyNs) and INs displayed layer-specific preference. These findings highlight the functional diversity of L1INs in modulating mPFC circuits and suggest their potential role in supporting higher order cognitive functions.

Abnormal Functional Attributes of Central Executive Network in Patients with Mild Cognitive Impairment Associated with End-Stage Renal Disease

RATIONALE AND OBJECTIVES

To assess changes in the central executive network (CEN) of patients with mild cognitive impairment (MCI) associated with end-stage renal disease (ESRD).

METHODS

A total of 121 patients with ESRD and 66 healthy controls (HCs) were enrolled. Patients were divided into an MCI group (n = 67) and a cognitively unimpaired group (n = 54). All participants underwent resting-state functional magnetic resonance imaging and were evaluated using the Montreal Cognitive Assessment (MoCA). The functional attributes of the CEN were calculated using three methods of functional connectivity (FC) analysis. Relationships among imaging features, cognitive scale scores, and clinical data were assessed, and a model was constructed to diagnose MCI in patients with ESRD.

RESULTS

The comparison of the three groups showed that there were significant differences in the FC values of five connection pairs within the CEN, and the CEN demonstrated significant differences in connectivity to ten brain regions. In patients with MCI associated with ESRD, the information transmission efficiency of the CEN was reduced, which demonstrates the characteristics of a random network to some extent. Significant correlations were observed among imaging parameters, cognitive scale scores, and clinical data. The diagnostic model constructed based on these results demonstrated excellent discrimination and calibration.

CONCLUSION

Alterations in the function of the CEN provide relevant bases for revealing the neuropathological mechanism of MCI in patients with ESRD. The diagnostic model developed in this study may help to establish more reliable imaging markers for detecting early cognitive impairment in this patient population.

Orexin mechanisms in the prelimbic cortex modulate the expression of contextual conditioned fear

RATIONALE

Despite the existing anatomical and physiological evidence pointing to the involvement of orexinergic projections from the lateral hypothalamus (LH) in regulating fear-related responses, little is known regarding the contribution of the orexin system in the prelimbic cortex (PL) on contextual fear.

OBJECTIVES

We investigated the role of orexin-A (OrxA) and orexin type 1 receptors (Orx1R) in the PL during the expression of contextual conditioned fear in mice.

METHODS

Neural tract tracing of the LH-PL pathway and Orx1R immunoreactivity in the PL of C57BL/6 male mice were performed. In a pharmacological approach, the animals were treated with either the Orx1R selective antagonist SB 334,867 (3, 30, and 300 nM/0.1 µL) or OrxA (28, 70, and 140 pmol/0.1 µL) in the PL before the test session of contextual fear conditioning.

RESULTS

Neural tract tracing deposits in the LH showed some perikarya, mainly axons and terminal buttons in the PL, suggesting LH-PL reciprocate pathways. Furthermore, we showed a profuse network comprised of Orx1R-labeled thin varicose fibers widely distributed in the same field of LH-PL pathways projection. The selective blockade of Orx1R with SB 334,867 at 30 and 300 nM in the PL caused a decrease in freezing response, whereas the treatment with OrxA at 140 pmol promoted an increase in freezing response.

CONCLUSION

In summary, these data confirmed an anatomical link between LH and PL, established the presence of Orx1R in the PL, and a modulatory role of the orexin system in such structure, possibly mainly via Orx1R, during contextual fear conditioning.

Trajectories of working memory and decision making abilities along juvenile development in mice

Rodents commonly serve as model organisms for the investigation of human mental disorders by capitalizing on behavioral commonalities. However, our understanding of the developmental dynamics of complex cognitive abilities in rodents remains incomplete. In this study, we examined spatial working memory as well as odor-and texture-based decision making in mice using a delayed non-match to sample task and a two-choice set-shifting task, respectively. Mice were investigated during different stages of development: pre-juvenile, juvenile, and young adult age. We show that, while working memory abilities in mice improve with age, decision making performance peaks during juvenile age by showing a sex-independent trajectory. Moreover, cFos expression, as a first proxy for neuronal activity, shows distinct age-and brain area-specific changes that relate to task-specific behavioral performance. The distinct developmental trajectories of working memory and decision making in rodents resemble those previously reported for humans.

The hemispheric differences in prefrontal function of Internet game disorder and non-Internet game disorder: an activation likelihood estimation meta-analysis

This study explored the differences in brain activation between individuals with and without Internet gaming disorder (IGD) through activation likelihood estimation analysis. In total, 39 studies were included based on the inclusion and exclusion criteria by searching the literature in the PubMed and Web of Science databases, as well as reading other reviews. The analysis revealed that the activated brain regions in IGD were the right inferior frontal gyrus, left cingulate gyrus, and left lentiform nucleus. In comparison, the activated brain regions in non-IGD were the left middle frontal, left inferior frontal, left anterior cingulate, left precentral, and right precentral gyri. The results of the present study on differences in activation further confirm existing theoretical hypotheses. Future studies should explore hemispheric differences in prefrontal brain function between IGD and non-IGD.

A shared threat-anticipation circuit is dynamically engaged at different moments by certain and uncertain threat

Temporal dynamics play a central role in models of emotion: "fear" is widely conceptualized as a phasic response to certain-and-imminent danger, whereas "anxiety" is a sustained response to uncertain-or-distal harm. Yet the underlying neurobiology remains contentious. Leveraging a translationally relevant fMRI paradigm and theory-driven modeling approach in 220 adult humans, we demonstrate that certain- and uncertain-threat anticipation recruit a shared circuit that encompasses the central extended amygdala (EAc), periaqueductal gray, midcingulate, and anterior insula. This circuit exhibits persistently elevated activation when threat is uncertain and distal, and transient bursts of activation just before certain encounters with threat. Although there is agreement that the EAc plays a critical role in orchestrating responses to threat, confusion persists about the respective contributions of its major subdivisions, the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (Ce). Here we used anatomical regions-of-interest to demonstrate that the BST and Ce exhibit statistically indistinguishable threat dynamics. Both regions exhibited activation dynamics that run counter to popular models, with the Ce showing sustained responses to uncertain-and-distal threat and the BST showing phasic responses to certain-and-imminent threat. For many scientists, feelings are the hallmark of fear and anxiety. Here we used an independently validated multivoxel brain 'signature' to covertly probe the moment-by-moment dynamics of anticipatory distress for the first time. Results mirrored the dynamics of neural activation. These observations provide fresh insights into the neurobiology of threat-elicited emotions and set the stage for more ambitious clinical and mechanistic research.

Enhancing Early Diagnosis of Bipolar Disorder in Adolescents Through Multimodal Neuroimaging

BACKGROUND

Bipolar disorder (BD), a severe neuropsychiatric condition, often appears during adolescence. Traditional diagnostic methods, which primarily rely on clinical interviews and single-modal magnetic resonance imaging (MRI) techniques, may have limitations in accuracy. This study aimed to improve adolescent BD diagnosis by integrating behavioral assessments with multimodal MRI. We hypothesized that this combination would enhance diagnostic accuracy for at-risk adolescents.

METHODS

A retrospective cohort of 309 participants, including patients with BD, offspring of patients with BD (with and without subthreshold symptoms), non-BD offspring with subthreshold symptoms, and healthy control participants, was analyzed. Behavioral attributes were integrated with MRI features from T1-weighted, resting-state functional MRI, and diffusion tensor imaging. Three diagnostic models were developed using GLMNET multinomial regression: a clinical diagnosis model based on behavioral attributes, an MRI-based model, and a comprehensive model integrating both datasets.

RESULTS

The comprehensive model achieved a prediction accuracy of 0.83 (95% CI, 0.72-0.92), significantly higher than the clinical (0.75) and MRI-based (0.65) models. Validation with an external cohort showed high accuracy (0.89, area under the curve = 0.95). Structural equation modeling revealed that clinical diagnosis (β = 0.487, p < .0001), parental BD history (β = -0.380, p < .0001), and global function (β = 0.578, p < .0001) significantly affected brain health, while psychiatric symptoms showed only a marginal influence (β = -0.112, p = .056).

CONCLUSIONS

This study highlights the value of integrating multimodal MRI with behavioral assessments for early diagnosis in at-risk adolescents. Combining neuroimaging enables more accurate patient subgroup distinctions, facilitating timely interventions and improving health outcomes. Our findings suggest a paradigm shift in BD diagnostics, advocating for incorporating advanced imaging techniques in routine evaluations.

Gray matter and cognitive alteration related to chronic obstructive pulmonary disease patients: combining ALE meta-analysis and MACM analysis

Chronic obstructive pulmonary disease (COPD) is frequently comorbid with cognitive impairment, but it has not been paid enough attention, and its neuroanatomical characteristics have not been fully identified. Voxel-based morphometric (VBM) studies comparing gray matter (GM) abnormalities in COPD patients with healthy controls (HCs) were searched using 8 electronic databases from the inception to March 2023. Stereotactic data were extracted and tested for convergence and differences using the activation likelihood estimation (ALE) method. Moreover, based on the ALE results, a structural meta-analytic connectivity modeling (MACM) was conducted to explore the co-atrophy pattern in patients with COPD. Last, behavioral analysis was performed to assess the functional roles of the regions affected by COPD. In total, 11 studies on COPD with 949 participants were included. Voxel-based meta-analysis revealed significant GM abnormalities in the right postcentral gyrus (including inferior parietal lobule), left precentral gyrus, and left cingulate gyrus (including paracentral lobule) in patients with COPD compared with HCs. Further MACM analysis revealed a deeper co-atrophy pattern between the brain regions with abnormal GM structure and the insula in COPD patients. Behavioral analysis showed that the abnormal GM structure in the left cingulate gyrus (including paracentral lobule) was strongly associated with cognitive function, especially executive function. COPD comorbid with cognitive impairment has a specific neurostructural basis of GM structural abnormalities, which may also involve a deeper co-atrophy pattern between the insula. These findings enhance our understanding of the underlying neuropathogenesis and suggest potential imaging markers for cognitive impairment in COPD patients. PROSPERO registration number: CRD42022298722.

A resting-state fMRI cross-sectional study of cardiorespiratory fitness decline after stroke

Objective

The present study aimed to investigate alterations in neural activity and reorganization of functional networks within critical brain regions associated with reduced cardiorespiratory fitness (CRF) in stroke patients. By employing resting-state functional magnetic resonance imaging (fMRI), we sought to identify specific brain areas that may be implicated in CRF decline among this patient population.

Methods

A total of 22 patients with stroke and 15 healthy subjects matched for age, gender, and body mass index were recruited. Rehabilitation assessments included peak oxygen uptake (VO2peak), peak work-rate, 10-meter walk test (10mWT), five times sit-to-stand test (FTSST), and 6-min walking distance (6MWD). Resting-state fMRI data were collected for the two groups, and correlation between changes in the amplitude of low-frequency fluctuations (ALFF) and CRF was analyzed to detect brain regions related to CRF and local neural activity in patients with stroke. On the basis of ALFF analysis, brain network analysis was performed, and the CRF-related brain regions in patients with stroke were selected as seed points. Functional connectivity (FC) analysis was the used to identify brain regions and networks potentially associated with CRF in patients with stroke.

Results

Patients with stroke exhibited significantly lower VO2peak, peak work-rate, 10mWT, and 6MWD compared to healthy controls (p < 0.001). FTSST was significantly higher in patients with stroke than healthy controls (p < 0.001). ALFF analysis identified CRF-related brain regions in patients with stroke, including the ipsilesional superior temporal gyrus (r = 0.56947, p = 0.00036), middle frontal gyrus (r = 0.62446, p = 0.00006), and precentral gyrus (r = 0.56866, p = 0.00036). FC analysis revealed that the functional connectivity of brain regions related to CRF in patients with stroke involved the ipsilesional M1 to ipsilesional precentral gyrus and contralesional postcentral gyrus, and the correlation coefficients were r = 0.54802 (p = 0.00065) and r = 0.49511 (p = 0.0025), respectively. The correlation coefficients of ipsilesional middle frontal gyrus to contralesional middle frontal gyrus, angular gyrus and ipsilesional superior frontal gyrus were r = 0.58617 (p = 0.00022), r = 0.57735 (p = 0.00028), and r = -0.65229 (p = 0.00002), respectively.

Conclusion

This study observed that CRF levels were lower in stroke patients compared to those in healthy individuals. Resting fMRI analysis was applied to identify CRF-related brain regions (ipsilesional superior temporal, middle frontal, precentral gyri) and networks in patients with stroke.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=151095.

Taichi on the brain: an activation likelihood estimated meta-analysis of functional neuroimaging data

Introduction

Tai Chi Chuan (TCC) is an exercise regimen renowned for its comprehensive benefits to both physical and mental health. The present research endeavor aims to elucidate the neurocognitive impacts of TCC compared to alternative exercise modalities or therapeutic interventions.

Methods

A systematic meta-analysis was undertaken, encompassing a rigorous review of diverse datasets, wherein 422 scholarly articles were examined, with a subset of 18 articles meeting the stringent criteria for inclusion in the analytical framework.

Results

The study cohort comprised 677 participants, characterized by a mean age of 56.52 ± 14.89 years and an average educational attainment of 11.06 ± 3.32 years. Noteworthy alterations in functional neural activity were identified within the superior frontal gyrus.

Discussion

This comprehensive analysis provides significant insights into the enduring neural modifications and the distinctive contributions of TCC to cognitive health. Nevertheless, it is imperative to acknowledge the potential for bias in smaller functional magnetic resonance imaging studies owing to their inconclusive outcomes. This observation underscores the critical need for collaborative, multicenter research initiatives with expanded sample sizes to enhance the robustness and generalizability of future findings.

Recurrent activity propagates through labile ensembles in macaque dorsolateral prefrontal microcircuits

Human and non-human primate studies clearly implicate the dorsolateral prefrontal cortex (dlPFC) as critical for advanced cognitive functions.1,2 It is thought that intracortical synaptic architectures within the dlPFC are the integral neurobiological substrate that gives rise to these processes.3,4,5,6,7 In the prevailing model, each cortical column makes up one fundamental processing unit composed of dense intrinsic connectivity, conceptualized as the "canonical" cortical microcircuit.3,8 Each cortical microcircuit receives sensory and cognitive information from upstream sources, which are represented by sustained activity within the microcircuit, referred to as persistent or recurrent activity.4,9 Via recurrent connections within the microcircuit, activity propagates for a variable length of time, thereby allowing temporary storage and computations to occur locally before ultimately passing a transformed representation to a downstream output.4,5,10 Competing theories regarding how microcircuit activity is coordinated have proven difficult to reconcile in vivo, where intercortical and intracortical computations cannot be fully dissociated.5,9,11,12 Here, using high-density calcium imaging of macaque dlPFC, we isolated intracortical computations by interrogating microcircuit networks ex vivo. Using peri-sulcal stimulation to evoke recurrent activity in deep layers, we found that activity propagates through stochastically assembled intracortical networks wherein orderly, predictable, low-dimensional collective dynamics arise from ensembles with highly labile cellular memberships. Microcircuit excitability covaried with individual cognitive performance, thus anchoring heuristic models of abstract cortical functions within quantifiable constraints imposed by the underlying synaptic architecture. Our findings argue against engram or localist architectures, together demonstrating that generation of high-fidelity population-level signals from distributed, labile networks is an intrinsic feature of dlPFC microcircuitry.

Opioidergic activation of the descending pain inhibitory system underlies placebo analgesia

Placebo analgesia is caused by inactive treatment, implicating endogenous brain function involvement. However, the neurobiological basis remains unclear. In this study, we found that μ-opioid signals in the medial prefrontal cortex (mPFC) activate the descending pain inhibitory system to initiate placebo analgesia in neuropathic pain rats. Chemogenetic manipulation demonstrated that specific activation of μ-opioid receptor-positive (MOR+) neurons in the mPFC or suppression of the mPFC-ventrolateral periaqueductal gray (vlPAG) circuit inhibited placebo analgesia in rats. MOR+ neurons in the mPFC are monosynaptically connected and directly inhibit layer V pyramidal neurons that project to the vlPAG via GABAA receptors. Thus, intrinsic opioid signaling in the mPFC disinhibits excitatory outflow to the vlPAG by suppressing MOR+ neurons, leading to descending pain inhibitory system activation that initiates placebo analgesia. Our results shed light on the fundamental neurobiological mechanism of the placebo effect that maximizes therapeutic efficacy and reduces adverse drug effects in medical practice.

Comparative transcriptomic rhythms in the mouse and human prefrontal cortex

Introduction

Alterations in multiple subregions of the human prefrontal cortex (PFC) have been heavily implicated in psychiatric diseases. Moreover, emerging evidence suggests that circadian rhythms in gene expression are present across the brain, including in the PFC, and that these rhythms are altered in disease. However, investigation into the potential circadian mechanisms underlying these diseases in animal models must contend with the fact that the human PFC is highly evolved and specialized relative to that of rodents.

Methods

Here, we use RNA sequencing to lay the groundwork for translational studies of molecular rhythms through a sex-specific, cross species comparison of transcriptomic rhythms between the mouse medial PFC (mPFC) and two subregions of the human PFC, the anterior cingulate cortex (ACC) and the dorsolateral PFC (DLPFC).

Results

We find that while circadian rhythm signaling is conserved across species and subregions, there is a phase shift in the expression of core clock genes between the mouse mPFC and human PFC subregions that differs by sex. Furthermore, we find that the identity of rhythmic transcripts is largely unique between the mouse mPFC and human PFC subregions, with the most overlap (20%, 236 transcripts) between the mouse mPFC and the human ACC in females. Nevertheless, we find that basic biological processes are enriched for rhythmic transcripts across species, with key differences between regions and sexes.

Discussion

Together, this work highlights both the evolutionary conservation of transcriptomic rhythms and the advancement of the human PFC, underscoring the importance of considering cross-species differences when using animal models.

Altered static and dynamic spontaneous brain activity in patients with dysthyroid optic neuropathy: a resting-state fMRI study

Purpose

To investigate static and dynamic brain functional alterations in dysthyroid optic neuropathy (DON) using resting-state functional MRI (rs-fMRI) with the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo).

Materials and methods

Fifty-seven thyroid-associated ophthalmopathy (TAO) patients (23 DON and 34 non-DON) and 27 healthy controls (HCs) underwent rs-fMRI scans. Static and dynamic ALFF (sALFF and dALFF) and ReHo (sReHo and dReHo) values were compared between groups. The support-vector machine (SVM) classification method was used to examine the diagnostic performance of the identified models.

Results

Compared to non-DON patients, DON patients showed decreased sALFF in the bilateral lingual gyrus (LING) and right cuneus (CUN), alongside increased sALFF in the bilateral medial part of the superior frontal gyrus, right dorsolateral part of the superior frontal gyrus (SFGdor), and right precentral gyrus. DON patients also exhibited decreased dALFF in the left LING and right CUN, together with increased dALFF in the right orbital part of the middle frontal gyrus and right SFGdor in comparison to non-DON patients. Meanwhile, DON patients had lower sReHo in the right LING, and higher sReHo and dReHo in the right supramarginal gyrus compared to non-DON patients. When detecting DON, the dALFF model showed optimal diagnostic performance (AUC 0.9987).

Conclusion

Dysthyroid optic neuropathy patients exhibited both static and dynamic brain functional alterations in visual, cognitive, and emotion-related brain regions, deepening our current understanding of the underlying neural mechanisms of this disease. Rs-fMRI-based metrics, especially dALFF, may serve as relevant neuroimaging markers for diagnosing DON.

The role of the prefrontal cortex in modulating aggression in humans and rodents

Accumulating evidence suggests that the prefrontal cortex (PFC) plays an important role in aggression. However, the findings regarding the key neural mechanisms and molecular pathways underlying the modulation of aggression by the PFC are relatively scattered, with many inconsistencies and areas that would benefit from exploration. Here, we highlight the relationship between the PFC and aggression in humans and rodents and describe the anatomy and function of the human PFC, along with homologous regions in rodents. At the molecular level, we detail how the major neuromodulators of the PFC impact aggression. At the circuit level, this review provides an overview of known and potential subcortical projections that regulate aggression in rodents. Finally, at the disease level, we review the correlation between PFC alterations and heightened aggression in specific human psychiatric disorders. Our review provides a framework for PFC modulation of aggression, resolves several intriguing paradoxes from previous studies, and illuminates new avenues for further study.

Adolescent Alcohol Exposure Dysregulates Developing Cortical GABA Circuits

Adolescence is a critical developmental period during which physical, behavioral, and neurobiological maturation occurs. Within the brain, the prefrontal cortex is one of the last brain regions to undergo remodeling, often into adulthood. These relatively late developmental changes leave the prefrontal cortex uniquely vulnerable to insults beginning in adolescence-including alcohol exposure. Adolescents initiate alcohol consumption at a high rate, increasing the risk of lasting consequences through impairing the typical development of the prefrontal cortex. In this chapter, we discuss the development of prefrontal circuitry and the current literature investigating how alcohol influences prefrontal development. We primarily focus on preclinical studies in rodent models, which allow for the study of specific populations of neurons in the prefrontal cortex. We identify several future directions for adolescent alcohol research, including greater focus on neuropeptides and stronger understanding of sex differences in brain maturation and alcohol consumption.

An excitatory neural circuit for descending inhibition of itch processing

Itch serves as a self-protection mechanism against harmful external agents, whereas uncontrolled and persistent itch severely influences the quality of life of patients and aggravates their diseases. Unfortunately, the existing treatments are largely ineffective. The current difficulty in treatment may be closely related to the fact that the central neural mechanisms underlying itch processing, especially descending inhibition of itch, are poorly understood. Here, we demonstrate that an excitatory descending neural circuit from rostral anterior cingulate cortex pyramidal (rACCPy) neurons to periaqueductal gray GABAergic (PAGGABA) neurons plays a key role in the inhibition of itch. The activity of itch-tagged rACCPy neurons decreases during the itch-evoked scratching period. Artificial activation or inhibition of the neural circuits significantly impairs or enhances itch processing, respectively. Thus, an excitatory neural circuit is identified as playing a crucial inhibitory role in descending regulation of itch, suggesting that it could be a potential target for treating itch.

Neural Network Excitation/Inhibition: A Key to Empathy and Empathy Impairment

Empathy is an ability to fully understand and feel the mental states of others. We emphasize that empathy is elicited by the transmission of pain, fear, and sensory information. In clinical studies, impaired empathy has been observed in most psychiatric conditions. However, the precise impairment mechanism of the network systems on the pathogenesis of empathy impairment in psychiatric disorders is still unclear. Multiple lines of evidence suggest that disturbances in the excitatory/inhibitory balance in neurologic disorders are key to empathetic impairment in psychiatric disorders. Therefore, we here describe the roles played by the anterior cingulate cortex- and medial prefrontal cortex-dependent neural circuits and their impairments in psychiatric disorders, including anxiety, depression, and autism. In addition, we review recent studies on the role of microglia in neural network excitation/inhibition imbalance, which contributes to a better understanding of the neural network excitation/inhibition imbalance and may open up innovative psychiatric therapies.

Effectiveness of non-invasive brain stimulation on depressive symptoms targeting prefrontal cortex in functional magnetic resonance imaging studies: a combined systematic review and meta-analysis

The prefrontal cortex (PFC) is a critical non-invasive brain stimulation (NIBS) target for treating depression. However, the alterations of brain activations post-intervention remain inconsistent and the clinical moderators that could improve symptomatic effectiveness are unclear. The study aim was to systematically review the effectiveness of NIBS on depressive symptoms targeting PFC in functional magnetic resonance imaging (fMRI) studies. In our study, we delivered a combined activation likelihood estimation (ALE) meta-analysis and meta-regression. Until November 2020, three databases (PubMed, Web of Science, EMBASE) were searched and 14 studies with a total sample size of 584 were included in the ALE meta-analysis; after NIBS, four clusters in left cerebrum revealed significant activation while two clusters in right cerebrum revealed significant deactivation (P < 0.001, cluster size >150 mm3). Eleven studies were statistically reanalyzed for depressive symptoms pre-post active-NIBS and the pooled effect size was very large [(d = 1.82, 95%CI (1.23, 2.40)]; significant moderators causing substantial heterogeneity (Chi squared = 75.25, P < 0.01; I 2 = 87%) were detected through subgroup analysis and univariate meta-regression. Multivariate meta-regression was then conducted accordingly and the model suggested good fitness (Q = 42.32, P < 0.01). In all, NIBS targeting PFC balanced three core depressive-related neurocognitive networks (the salience network, the default mode network, and the central executive network); the striatum played a central role and might serve as a candidate treatment biomarker; gender difference, treatment-resistant condition, comorbidity, treatment duration, and localization all contributed to moderating depressive symptoms during NIBS. More high-quality, multi-center randomized controlled trails delivering personalized NIBS are needed for clinical practice in the future.

Learning-dependent gating of hippocampal inputs by frontal interneurons

The hippocampus is a brain region that is essential for the initial encoding of episodic memories. However, the consolidation of these memories is thought to occur in the neocortex, under guidance of the hippocampus, over the course of days and weeks. Communication between the hippocampus and the neocortex during hippocampal sharp wave-ripple oscillations is believed to be critical for this memory consolidation process. Yet, the synaptic and circuit basis of this communication between brain areas is largely unclear. To address this problem, we perform in vivo whole-cell patch-clamp recordings in the frontal neocortex and local field potential recordings in CA1 of head-fixed mice exposed to a virtual-reality environment. In mice trained in a goal-directed spatial task, we observe a depolarization in frontal principal neurons during hippocampal ripple oscillations. Both this ripple-associated depolarization and goal-directed task performance can be disrupted by chemogenetic inactivation of somatostatin-positive (SOM+) interneurons. In untrained mice, a ripple-associated depolarization is not observed, but it emerges when frontal parvalbumin-positive (PV+) interneurons are inactivated. These results support a model where SOM+ interneurons inhibit PV+ interneurons during hippocampal activity, thereby acting as a disinhibitory gate for hippocampal inputs to neocortical principal neurons during learning.

Comparing mouse and human cingulate cortex organization using functional connectivity

The subdivisions of the extended cingulate cortex of the human brain are implicated in a number of high-level behaviors and affected by a range of neuropsychiatric disorders. Its anatomy, function, and response to therapeutics are often studied using non-human animals, including the mouse. However, the similarity of human and mouse frontal cortex, including cingulate areas, is still not fully understood. Some accounts emphasize resemblances between mouse cingulate cortex and human cingulate cortex while others emphasize similarities with human granular prefrontal cortex. We use comparative neuroimaging to study the connectivity of the cingulate cortex in the mouse and human, allowing comparisons between mouse 'gold standard' tracer and imaging data, and, in addition, comparison between the mouse and the human using comparable imaging data. We find overall similarities in organization of the cingulate between species, including anterior and midcingulate areas and a retrosplenial area. However, human cingulate contains subareas with a more fine-grained organization than is apparent in the mouse and it has connections to prefrontal areas not present in the mouse. Results such as these help formally address between-species brain organization and aim to improve the translation from preclinical to human results.

Thematic and intertextual analysis from a feasibility study of the Bonny Method of Guided Imagery and Music with clients in eating disorder treatment

Introduction

Eating disorders (ED) are characterized by serious and persistent disturbances with eating, weightcontrol, and body image. Symptoms impact physical health, psychosocial functioning, and can be life-threatening. Individuals diagnosed with an ED experience numerous medical and psychiatric comorbidities due to issues caused by or underlying the ED. Therefore, it is vital to address the complex nature of an ED, as well as the comorbid and underlying issues. This necessitates a psychotherapeutic approach that can help to uncover, explore, and support working through unresolved emotions and experiences. Guided Imagery and Music (GIM) is an in-depth music psychotherapy approach utilizing therapist-programmed music to support the client in uncovering and examining underlying and unresolved issues. The literature surrounding the use of GIM with clients in ED treatment is anecdotal and comprised primarily of clinical case studies.

Method

This secondary analysis, based on a descriptive feasibility study that integrated GIM sessions into the client's regular ED treatment and examined 116 transcripts from a series of sessions of eight clients.

Results

Thematic analysis of the transcripts identified nine subthemes and three themes that emerged. These themes include emotional landscape (feeling stuck, acknowledging emotions, and working through unresolved emotions), relationships (self, others, and eating disorders), and transformation and growth (finding strength, change, and empowerment). A short series of GIM sessions helped ED clients identify and address issues underlying the ED and to gain or reclaim a sense of self that enabled them to make choices for their life that support their recovery and sense of empowerment. Intertextual analysis revealed imagery indicative of the Hero's Journey.

Discussion

Further, how engagement in this embodied aesthetic experience stimulates perceptual, cognitive, and affective brain functions which are key in fostering behavioural and psychological change is explicated as it relates to ED treatment and recovery.

Translation and validation of the abbreviated Prefrontal Symptoms Inventory (PSI-20): A tool for assessing prefrontal symptoms in English-speaking populations

This study introduces the translation and validation of the Prefrontal Symptoms Inventory (PSI) into English, aiming to provide an ecologically valid tool for assessing prefrontal symptoms in English-speaking populations in the United States. The prefrontal cortex (PFC) plays a crucial role in executive functions and other higher-order cognitive processes, with dysfunctions in this area associated with various cognitive, emotional and behavioural changes. Despite the existence of established tools like the Dysexecutive Questionnaire (DEX), the PSI addresses limitations found in the literature, presenting a novel ecologically valid tool for assessing prefrontal symptoms. The current study, involving 226 English-speaking participants, lays a foundational step for validating the PSI for use in a new population. Semi-confirmatory factorial analysis revealed a unidimensional structure, mirroring the Spanish version with robust fit indicators. Additionally, in assessing convergent validity, the abbreviated version (PSI-20) exhibited high correlations with DEX scores and moderate correlations with Psychological Stress Scale and General Health Questionnaire-12 scores. These findings align with previous reports, supporting the PSI-20's measurement of similar constructs related to prefrontal cortex activity and mental health components. The results of this study overall highlight the PSI's potential contribution to advancing prefrontal symptom evaluation in clinical and non-clinical settings.

A tradeoff between efficiency and robustness in the hippocampal-neocortical memory network during human and rodent sleep

Sleep constitutes a brain state of disengagement from the external world that supports memory consolidation and restores cognitive resources. The precise mechanisms how sleep and its varied stages support information processing remain largely unknown. Synaptic scaling models imply that daytime learning accumulates neural information, which is then consolidated and downregulated during sleep. Currently, there is a lack of in-vivo data from humans and rodents that elucidate if, and how, sleep renormalizes information processing capacities. From an information-theoretical perspective, a consolidation process should entail a reduction in neural pattern variability over the course of a night. Here, in a cross-species intracranial study, we identify a tradeoff in the neural population code during sleep where information coding efficiency is higher in the neocortex than in hippocampal archicortex in humans than in rodents as well as during wakefulness compared to sleep. Critically, non-REM sleep selectively reduces information coding efficiency through pattern repetition in the neocortex in both species, indicating a transition to a more robust information coding regime. Conversely, the coding regime in the hippocampus remained consistent from wakefulness to non-REM sleep. These findings suggest that new information could be imprinted to the long-term mnemonic storage in the neocortex through pattern repetition during sleep. Lastly, our results show that task engagement increased coding efficiency, while medically-induced unconsciousness disrupted the population code. In sum, these findings suggest that neural pattern variability could constitute a fundamental principle underlying cognitive engagement and memory formation, while pattern repetition reflects robust coding, possibly underlying the consolidation process.

Accumulation of mitochondrial DNA with a point mutation in tRNALeu(UUR) gene induces brain dysfunction in mice

Brain functions are mediated via the complex interplay between several complex factors, and hence, identifying the underlying cause of an abnormality within a certain brain region can be challenging. In mitochondrial disease, abnormalities in brain function are thought to be attributed to accumulation of mitochondrial DNA (mtDNA) with pathogenic mutations; however, only few previous studies have directly demonstrated that accumulation of mutant mtDNA induced abnormalities in brain function. Herein, we examined the effects of mtDNA mutations on brain function via behavioral analyses using a mouse model with an A2748G point mutation in mtDNA tRNALeu(UUR). Our results revealed that mice with a high percentage of mutant mtDNA showed a characteristic trend toward reduced prepulse inhibition and memory-dependent test performance, similar to that observed in psychiatric disorders, such as schizophrenia; however, muscle strength and motor coordination were not markedly affected. Upon examining the hippocampus and frontal lobes of the brain, mitochondrial morphology was abnormal, and the brain weight was slightly reduced. These results indicate that the predominant accumulation of a point mutation in the tRNALeu(UUR) gene may affect brain functions, particularly the coordination of sensory and motor functions and memory processes. These abnormalities probably caused by both direct effects of accumulation of the mutant mtDNA in neuronal cells and indirect effects via changes of systemic extracellular environments. Overall, these findings will lead to a better understanding of the pathogenic mechanism underlying this complex disease and facilitate the development of optimal treatment methods.

Depicting Primate-Like Granular Dorsolateral Prefrontal Cortex in the Chinese Tree Shrew

It remains unknown whether the Chinese tree shrew, regarded as the closest sister of primate, has evolved a dorsolateral prefrontal cortex (dlPFC) comparable with primates that is characterized by a fourth layer (L4) enriched with granular cells and reciprocal connections with the mediodorsal nucleus (MD). Here, we reported that following AAV-hSyn-EGFP expression in the MD neurons, the fluorescence micro-optical sectioning tomography revealed their projection trajectories and targeted brain areas, such as the hippocampus, the corpus striatum, and the dlPFC. Cre-dependent transsynaptic viral tracing identified the MD projection terminals that targeted the L4 of the dlPFC, in which the presence of granular cells was confirmed via cytoarchitectural studies by using the Nissl, Golgi, and vGlut2 stainings. Additionally, the L5/6 of the dlPFC projected back to the MD. These results suggest that the tree shrew has evolved a primate-like dlPFC which can serve as an alternative for studying cognition-related functions of the dlPFC.

Reduced functional connectivity induced by longitudinal alterations of structure and perfusion may be associated with cognitive impairment in patients on maintenance hemodialysis

Hemodialysis (HD) leads to cognitive impairment; however, the pathophysiology of maintenance HD remains unclear. This study aimed to investigate the longitudinal alterations in gray matter volume (GMV) and cerebral blood flow (CBF) in patients on HD at follow-up compared with baseline, examine the alterations in functional connectivity (FC) by defining co-changed brain regions as seed points, and investigate the correlation between the co-changed brain regions and neuropsychological test scores. Twenty-seven patients with HD and 30 healthy controls were enrolled in this study. All participants underwent high-resolution T1-weighted imaging, arterial spin labeling, and functional MR imaging to measure GMV, CBF, and FC. The patients on HD were assessed at baseline and 3 years subsequently. The right and left medial superior frontal gyrus (SFGmed.L) exhibited significantly lower GMV and CBF in patients on HD at follow-up compared with baseline and lower FC between the SFGmed.L and left middle temporal gyrus (MTG.L). FC between the SFGmed.L and MTG.L was positively correlated with neuropsychological test scores in the HD group at follow-up. Reduced GMV and CBF may result in decreased FC between the SFGmed.L and MTG.L, which may be associated with cognitive impairment in patients on maintenance HD. Our findings provide unique insights into the pathological mechanisms of patients on maintenance HD with cognitive impairment.

Development of Prefrontal Circuits and Cognitive Abilities

The prefrontal cortex is considered as the site of multifaceted higher-order cognitive abilities. These abilities emerge late in life long after full sensorimotor maturation, in line with the protracted development of prefrontal circuits that has been identified on molecular, structural, and functional levels. Only recently, as a result of the impressive methodological progress of the last several decades, the mechanisms and clinical implications of prefrontal development have begun to be elucidated, yet major knowledge gaps still persist. Here, we provide an overview on how prefrontal circuits develop to enable multifaceted cognitive processing at adulthood. First, we review recent insights into the mechanisms of prefrontal circuit assembly, with a focus on the contribution of early electrical activity. Second, we highlight the major reorganization of prefrontal circuits during adolescence. Finally, we link the prefrontal plasticity during specific developmental time windows to mental health disorders and discuss potential approaches for therapeutic interventions.

Comparative transcriptomic rhythms in the mouse and human prefrontal cortex

Alterations in multiple subregions of the human prefrontal cortex (PFC) have been heavily implicated in psychiatric diseases. Moreover, emerging evidence suggests that circadian rhythms in gene expression are present across the brain, including in the PFC, and that these rhythms are altered in disease. However, investigation into the potential circadian mechanisms underlying these diseases in animal models must contend with the fact that the human PFC is highly evolved and specialized relative to that of rodents. Here, we use RNA sequencing to lay the groundwork for translational studies of molecular rhythms through a sex-specific, cross species comparison of transcriptomic rhythms between the mouse medial PFC (mPFC) and two subregions of the human PFC, the anterior cingulate cortex (ACC) and the dorsolateral PFC (DLPFC). We find that while circadian rhythm signaling is conserved across species and subregions, there is a phase shift in the expression of core clock genes between the mouse mPFC and human PFC subregions that differs by sex. Furthermore, we find that the identity of rhythmic transcripts is largely unique between the mouse mPFC and human PFC subregions, with the most overlap (20%, 236 transcripts) between the mouse mPFC and the human ACC in females. Nevertheless, we find that basic biological processes are enriched for rhythmic transcripts across species, with key differences between regions and sexes. Together, this work highlights both the evolutionary conservation of transcriptomic rhythms and the advancement of the human PFC, underscoring the importance of considering cross-species differences when using animal models.

BFAST: joint dimension reduction and spatial clustering with Bayesian factor analysis for zero-inflated spatial transcriptomics data

The development of spatially resolved transcriptomics (ST) technologies has made it possible to measure gene expression profiles coupled with cellular spatial context and assist biologists in comprehensively characterizing cellular phenotype heterogeneity and tissue microenvironment. Spatial clustering is vital for biological downstream analysis. However, due to high noise and dropout events, clustering spatial transcriptomics data poses numerous challenges due to the lack of effective algorithms. Here we develop a novel method, jointly performing dimension reduction and spatial clustering with Bayesian Factor Analysis for zero-inflated Spatial Transcriptomics data (BFAST). BFAST has showcased exceptional performance on simulation data and real spatial transcriptomics datasets, as proven by benchmarking against currently available methods. It effectively extracts more biologically informative low-dimensional features compared to traditional dimensionality reduction approaches, thereby enhancing the accuracy and precision of clustering.

BayeSMART: Bayesian clustering of multi-sample spatially resolved transcriptomics data

The field of spatially resolved transcriptomics (SRT) has greatly advanced our understanding of cellular microenvironments by integrating spatial information with molecular data collected from multiple tissue sections or individuals. However, methods for multi-sample spatial clustering are lacking, and existing methods primarily rely on molecular information alone. This paper introduces BayeSMART, a Bayesian statistical method designed to identify spatial domains across multiple samples. BayeSMART leverages artificial intelligence (AI)-reconstructed single-cell level information from the paired histology images of multi-sample SRT datasets while simultaneously considering the spatial context of gene expression. The AI integration enables BayeSMART to effectively interpret the spatial domains. We conducted case studies using four datasets from various tissue types and SRT platforms, and compared BayeSMART with alternative multi-sample spatial clustering approaches and a number of state-of-the-art methods for single-sample SRT analysis, demonstrating that it surpasses existing methods in terms of clustering accuracy, interpretability, and computational efficiency. BayeSMART offers new insights into the spatial organization of cells in multi-sample SRT data.

Local and long-range input balance: A framework for investigating frontal cognitive circuit maturation in health and disease

Frontal cortical circuits undergo prolonged maturation across childhood and adolescence; however, it remains unknown what specific changes are occurring at the circuit level to establish adult cognitive function. With the recent advent of circuit dissection techniques, it is now feasible to examine circuit-specific changes in connectivity, activity, and function in animal models. Here, we propose that the balance of local and long-range inputs onto frontal cognitive circuits is an understudied metric of circuit maturation. This review highlights research on a frontal-sensory attention circuit that undergoes refinement of local/long-range connectivity, regulated by circuit activity and neuromodulatory signaling, and evaluates how this process may occur generally in the frontal cortex to support adult cognitive behavior. Notably, this balance can be bidirectionally disrupted through various mechanisms relevant to psychiatric disorders. Pharmacological or environmental interventions to normalize or reset the local and long-range balance could hold great therapeutic promise to prevent or rescue cognitive deficits.

Abnormal Dynamic Reconfiguration of Multilayer Temporal Networks in Patients with Bipolar Disorder

BACKGROUND

Multilayer networks have been used to identify abnormal dynamic reconfiguration in bipolar disorder (BD). However, these studies ignore the differences in information interactions between adjacent layers when constructing multilayer networks, and the analysis of dynamic reconfiguration is not comprehensive enough; Methods: Resting-state functional magnetic resonance imaging data were collected from 46 BD patients and 54 normal controls. A multilayer temporal network was constructed for each subject, and inter-layer coupling of different nodes was considered using network similarity. The promiscuity, recruitment, and integration coefficients were calculated to quantify the different dynamic reconfigurations between the two groups; Results: The global inter-layer coupling, recruitment, and integration coefficients were significantly lower in BD patients. These results were further observed in the attention network and the limbic/paralimbic and subcortical network, reflecting reduced temporal stability, intra- and inter-subnetwork communication abilities in BD patients. The whole-brain promiscuity was increased in BD patients. The same results were observed in the somatosensory/motor and auditory network, reflecting more functional interactions; Conclusions: This study discovered abnormal dynamic interactions of BD from the perspective of dynamic reconfiguration, which can help to understand the pathological mechanisms of BD.

Monoaminergic Modulation of Learning and Cognitive Function in the Prefrontal Cortex

Extensive research has shed light on the cellular and functional underpinnings of higher cognition as influenced by the prefrontal cortex. Neurotransmitters act as key regulatory molecules within the PFC to assist with synchronizing cognitive state and arousal levels. The monoamine family of neurotransmitters, including dopamine, serotonin, and norepinephrine, play multifaceted roles in the cognitive processes behind learning and memory. The present review explores the organization and signaling patterns of monoamines within the PFC, as well as elucidates the numerous roles played by monoamines in learning and higher cognitive function.