Decoding molecular mechanisms: brain aging and Alzheimer's disease

The complex morphological, anatomical, physiological, and chemical mechanisms within the aging brain have been the hot topic of research for centuries. The aging process alters the brain structure that affects functions and cognitions, but the worsening of such processes contributes to the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease. Beyond these observable, mild morphological shifts, significant functional modifications in neurotransmission and neuronal activity critically influence the aging brain. Understanding these changes is important for maintaining cognitive health, especially given the increasing prevalence of age-related conditions that affect cognition. This review aims to explore the age-induced changes in brain plasticity and molecular processes, differentiating normal aging from the pathogenesis of Alzheimer's disease, thereby providing insights into predicting the risk of dementia, particularly Alzheimer's disease.

Bidirectional regulation of the brain-gut-microbiota axis following traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202508000-00002/figure1/v/2024-09-30T120553Z/r/image-tiff Traumatic brain injury is a prevalent disorder of the central nervous system. In addition to primary brain parenchymal damage, the enduring biological consequences of traumatic brain injury pose long-term risks for patients with traumatic brain injury; however, the underlying pathogenesis remains unclear, and effective intervention methods are lacking. Intestinal dysfunction is a significant consequence of traumatic brain injury. Being the most densely innervated peripheral tissue in the body, the gut possesses multiple pathways for the establishment of a bidirectional "brain-gut axis" with the central nervous system. The gut harbors a vast microbial community, and alterations of the gut niche contribute to the progression of traumatic brain injury and its unfavorable prognosis through neuronal, hormonal, and immune pathways. A comprehensive understanding of microbiota-mediated peripheral neuroimmunomodulation mechanisms is needed to enhance treatment strategies for traumatic brain injury and its associated complications. We comprehensively reviewed alterations in the gut microecological environment following traumatic brain injury, with a specific focus on the complex biological processes of peripheral nerves, immunity, and microbes triggered by traumatic brain injury, encompassing autonomic dysfunction, neuroendocrine disturbances, peripheral immunosuppression, increased intestinal barrier permeability, compromised responses of sensory nerves to microorganisms, and potential effector nuclei in the central nervous system influenced by gut microbiota. Additionally, we reviewed the mechanisms underlying secondary biological injury and the dynamic pathological responses that occur following injury to enhance our current understanding of how peripheral pathways impact the outcome of patients with traumatic brain injury. This review aimed to propose a conceptual model for future risk assessment of central nervous system-related diseases while elucidating novel insights into the bidirectional effects of the "brain-gut-microbiota axis."

Stepping up after spinal cord injury: negotiating an obstacle during walking

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate obstacles. After spinal cord injury, stepping over an obstacle becomes challenging. Stepping over an obstacle requires sensorimotor transformations in several structures of the brain, including the parietal cortex, premotor cortex, and motor cortex. Sensory information and planning are transformed into motor commands, which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory, coordinate the limbs, and maintain balance. After spinal cord injury, bidirectional communication between the brain and spinal cord is disrupted and animals, including humans, fail to voluntarily modify limb trajectory to step over an obstacle. Therefore, in this review, we discuss the neuromechanical control of stepping over an obstacle, why it fails after spinal cord injury, and how it recovers to a certain extent.

The complex roles of m 6 A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

N6-methyladenosine (m 6 A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m 6 A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m 6 A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m 6 A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m 6 A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m 6 A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m 6 A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m 6 A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m 6 A's role in neurodegenerative processes. The roles of m 6 A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be attributed to the time-specific nature of m 6 A and its varying effects on distinct brain regions and in different environments.

The effects of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents: a meta-analysis

Brain-derived neurotrophic factor is a crucial neurotrophic factor that plays a significant role in brain health. Although the vast majority of meta-analyses have confirmed that exercise interventions can increase brain-derived neurotrophic factor levels in children and adolescents, the effects of specific types of exercise on brain-derived neurotrophic factor levels are still controversial. To address this issue, we used meta-analytic methods to quantitatively evaluate, analyze, and integrate relevant studies. Our goals were to formulate general conclusions regarding the use of exercise interventions, explore the physiological mechanisms by which exercise improves brain health and cognitive ability in children and adolescents, and provide a reliable foundation for follow-up research. We used the PubMed, Web of Science, Science Direct, Springer, Wiley Online Library, Weipu, Wanfang, and China National Knowledge Infrastructure databases to search for randomized controlled trials examining the influences of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents. The extracted data were analyzed using ReviewManager 5.3. According to the inclusion criteria, we assessed randomized controlled trials in which the samples were mainly children and adolescents, and the outcome indicators were measured before and after the intervention. We excluded animal experiments, studies that lacked a control group, and those that did not report quantitative results. The mean difference (MD; before versus after intervention) was used to evaluate the effect of exercise on brain-derived neurotrophic factor levels in children and adolescents. Overall, 531 participants (60 children and 471 adolescents, 10.9-16.1 years) were included from 13 randomized controlled trials. Heterogeneity was evaluated using the Q statistic and I2 test provided by ReviewManager software. The meta-analysis showed that there was no heterogeneity among the studies (P = 0.67, I2 = 0.00%). The combined effect of the interventions was significant (MD = 2.88, 95% CI: 1.53-4.22, P < 0.0001), indicating that the brain-derived neurotrophic factor levels of the children and adolescents in the exercise group were significantly higher than those in the control group. In conclusion, different types of exercise interventions significantly increased brain-derived neurotrophic factor levels in children and adolescents. However, because of the small sample size of this meta-analysis, more high-quality research is needed to verify our conclusions. This meta-analysis was registered at PROSPERO (registration ID: CRD42023439408).

Potassium and calcium channels in different nerve cells act as therapeutic targets in neurological disorders

The central nervous system, information integration center of the body, is mainly composed of neurons and glial cells. The neuron is one of the most basic and important structural and functional units of the central nervous system, with sensory stimulation and excitation conduction functions. Astrocytes and microglia belong to the glial cell family, which is the main source of cytokines and represents the main defense system of the central nervous system. Nerve cells undergo neurotransmission or gliotransmission, which regulates neuronal activity via the ion channels, receptors, or transporters expressed on nerve cell membranes. Ion channels, composed of large transmembrane proteins, play crucial roles in maintaining nerve cell homeostasis. These channels are also important for control of the membrane potential and in the secretion of neurotransmitters. A variety of cellular functions and life activities, including functional regulation of the central nervous system, the generation and conduction of nerve excitation, the occurrence of receptor potential, heart pulsation, smooth muscle peristalsis, skeletal muscle contraction, and hormone secretion, are closely related to ion channels associated with passive transmembrane transport. Two types of ion channels in the central nervous system, potassium channels and calcium channels, are closely related to various neurological disorders, including Alzheimer's disease, Parkinson's disease, and epilepsy. Accordingly, various drugs that can affect these ion channels have been explored deeply to provide new directions for the treatment of these neurological disorders. In this review, we focus on the functions of potassium and calcium ion channels in different nerve cells and their involvement in neurological disorders such as Parkinson's disease, Alzheimer's disease, depression, epilepsy, autism, and rare disorders. We also describe several clinical drugs that target potassium or calcium channels in nerve cells and could be used to treat these disorders. We concluded that there are few clinical drugs that can improve the pathology these diseases by acting on potassium or calcium ions. Although a few novel ion-channel-specific modulators have been discovered, meaningful therapies have largely not yet been realized. The lack of target-specific drugs, their requirement to cross the blood-brain barrier, and their exact underlying mechanisms all need further attention. This review aims to explain the urgent problems that need research progress and provide comprehensive information aiming to arouse the research community's interest in the development of ion channel-targeting drugs and the identification of new therapeutic targets for that can increase the cure rate of nervous system diseases and reduce the occurrence of adverse reactions in other systems.

Decoding the nexus: branched-chain amino acids and their connection with sleep, circadian rhythms, and cardiometabolic health

The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and, either directly or indirectly, overall body health, encompassing metabolic and cardiovascular well-being. Given the heightened metabolic activity of the brain, there exists a considerable demand for nutrients in comparison to other organs. Among these, the branched-chain amino acids, comprising leucine, isoleucine, and valine, display distinctive significance, from their contribution to protein structure to their involvement in overall metabolism, especially in cerebral processes. Among the first amino acids that are released into circulation post-food intake, branched-chain amino acids assume a pivotal role in the regulation of protein synthesis, modulating insulin secretion and the amino acid sensing pathway of target of rapamycin. Branched-chain amino acids are key players in influencing the brain's uptake of monoamine precursors, competing for a shared transporter. Beyond their involvement in protein synthesis, these amino acids contribute to the metabolic cycles of γ-aminobutyric acid and glutamate, as well as energy metabolism. Notably, they impact GABAergic neurons and the excitation/inhibition balance. The rhythmicity of branched-chain amino acids in plasma concentrations, observed over a 24-hour cycle and conserved in rodent models, is under circadian clock control. The mechanisms underlying those rhythms and the physiological consequences of their disruption are not fully understood. Disturbed sleep, obesity, diabetes, and cardiovascular diseases can elevate branched-chain amino acid concentrations or modify their oscillatory dynamics. The mechanisms driving these effects are currently the focal point of ongoing research efforts, since normalizing branched-chain amino acid levels has the ability to alleviate the severity of these pathologies. In this context, the Drosophila model, though underutilized, holds promise in shedding new light on these mechanisms. Initial findings indicate its potential to introduce novel concepts, particularly in elucidating the intricate connections between the circadian clock, sleep/wake, and metabolism. Consequently, the use and transport of branched-chain amino acids emerge as critical components and orchestrators in the web of interactions across multiple organs throughout the sleep/wake cycle. They could represent one of the so far elusive mechanisms connecting sleep patterns to metabolic and cardiovascular health, paving the way for potential therapeutic interventions.

Gut microbiota-astrocyte axis: new insights into age-related cognitive decline

With the rapidly aging human population, age-related cognitive decline and dementia are becoming increasingly prevalent worldwide. Aging is considered the main risk factor for cognitive decline and acts through alterations in the composition of the gut microbiota, microbial metabolites, and the functions of astrocytes. The microbiota-gut-brain axis has been the focus of multiple studies and is closely associated with cognitive function. This article provides a comprehensive review of the specific changes that occur in the composition of the gut microbiota and microbial metabolites in older individuals and discusses how the aging of astrocytes and reactive astrocytosis are closely related to age-related cognitive decline and neurodegenerative diseases. This article also summarizes the gut microbiota components that affect astrocyte function, mainly through the vagus nerve, immune responses, circadian rhythms, and microbial metabolites. Finally, this article summarizes the mechanism by which the gut microbiota-astrocyte axis plays a role in Alzheimer's and Parkinson's diseases. Our findings have revealed the critical role of the microbiota-astrocyte axis in age-related cognitive decline, aiding in a deeper understanding of potential gut microbiome-based adjuvant therapy strategies for this condition.

Repetitive traumatic brain injury-induced complement C1-related inflammation impairs long-term hippocampal neurogenesis

JOURNAL/nrgr/04.03/01300535-202503000-00027/figure1/v/2024-06-17T092413Z/r/image-tiff Repetitive traumatic brain injury impacts adult neurogenesis in the hippocampal dentate gyrus, leading to long-term cognitive impairment. However, the mechanism underlying this neurogenesis impairment remains unknown. In this study, we established a male mouse model of repetitive traumatic brain injury and performed long-term evaluation of neurogenesis of the hippocampal dentate gyrus after repetitive traumatic brain injury. Our results showed that repetitive traumatic brain injury inhibited neural stem cell proliferation and development, delayed neuronal maturation, and reduced the complexity of neuronal dendrites and spines. Mice with repetitive traumatic brain injuryalso showed deficits in spatial memory retrieval. Moreover, following repetitive traumatic brain injury, neuroinflammation was enhanced in the neurogenesis microenvironment where C1q levels were increased, C1q binding protein levels were decreased, and canonical Wnt/β-catenin signaling was downregulated. An inhibitor of C1 reversed the long-term impairment of neurogenesis induced by repetitive traumatic brain injury and improved neurological function. These findings suggest that repetitive traumatic brain injury-induced C1-related inflammation impairs long-term neurogenesis in the dentate gyrus and contributes to spatial memory retrieval dysfunction.

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

During the development of the nervous system, there is an overproduction of neurons and synapses. Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening. We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway, at the neuromuscular junction, in the axonal development and synapse elimination process versus the synapse consolidation. The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination, in relation to other molecular pathways that we and others have found to regulate this process. In particular, we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors, coupled to downstream serine-threonine protein kinases A and C (PKA and PKC) and voltage-gated calcium channels, at different nerve endings in developmental competition. The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site, influence each other, and require careful studies to individualize the mechanisms of specific endings. We describe an activity-dependent balance (related to the extent of transmitter release) between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals. The downstream displacement of the PKA/PKC activity ratio to lower values, both in competing nerve terminals and at postsynaptic sites, plays a relevant role in controlling the elimination of supernumerary synapses. Finally, calcium entry through L- and P/Q- subtypes of voltage-gated calcium channels (both channels are present, together with the N-type channel in developing nerve terminals) contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination (the weakest in acetylcholine release and those that have already become silent). The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development. Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.

AAV mediated carboxyl terminus of Hsp70 interacting protein overexpression mitigates the cognitive and pathological phenotypes of APP/PS1 mice

JOURNAL/nrgr/04.03/01300535-202501000-00033/figure1/v/2024-05-14T021156Z/r/image-tiff The E3 ubiquitin ligase, carboxyl terminus of heat shock protein 70 (Hsp70) interacting protein (CHIP), also functions as a co-chaperone and plays a crucial role in the protein quality control system. In this study, we aimed to investigate the neuroprotective effect of overexpressed CHIP on Alzheimer's disease. We used an adeno-associated virus vector that can cross the blood-brain barrier to mediate CHIP overexpression in APP/PS1 mouse brain. CHIP overexpression significantly ameliorated the performance of APP/PS1 mice in the Morris water maze and nest building tests, reduced amyloid-β plaques, and decreased the expression of both amyloid-β and phosphorylated tau. CHIP also alleviated the concentration of microglia and astrocytes around plaques. In APP/PS1 mice of a younger age, CHIP overexpression promoted an increase in ADAM10 expression and inhibited β-site APP cleaving enzyme 1, insulin degrading enzyme, and neprilysin expression. Levels of HSP70 and HSP40, which have functional relevance to CHIP, were also increased. Single nuclei transcriptome sequencing in the hippocampus of CHIP overexpressed mice showed that the lysosomal pathway and oligodendrocyte-related biological processes were up-regulated, which may also reflect a potential mechanism for the neuroprotective effect of CHIP. Our research shows that CHIP effectively reduces the behavior and pathological manifestations of APP/PS1 mice. Indeed, overexpression of CHIP could be a beneficial approach for the treatment of Alzheimer's disease.

Microglia lactylation in relation to central nervous system diseases

The development of neurodegenerative diseases is closely related to the disruption of central nervous system homeostasis. Microglia, as innate immune cells, play important roles in the maintenance of central nervous system homeostasis, injury response, and neurodegenerative diseases. Lactate has been considered a metabolic waste product, but recent studies are revealing ever more of the physiological functions of lactate. Lactylation is an important pathway in lactate function and is involved in glycolysis-related functions, macrophage polarization, neuromodulation, and angiogenesis and has also been implicated in the development of various diseases. This review provides an overview of the lactate metabolic and homeostatic regulatory processes involved in microglia lactylation, histone versus non-histone lactylation, and therapeutic approaches targeting lactate. Finally, we summarize the current research on microglia lactylation in central nervous system diseases. A deeper understanding of the metabolic regulatory mechanisms of microglia lactylation will provide more options for the treatment of central nervous system diseases.

The interaction between KIF21A and KANK1 regulates dendritic morphology and synapse plasticity in neurons

JOURNAL/nrgr/04.03/01300535-202501000-00029/figure1/v/2024-05-14T021156Z/r/image-tiff Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory. Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1; however, whether KIF21A modulates dendritic structure and function in neurons remains unknown. In this study, we found that KIF21A was distributed in a subset of dendritic spines, and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines. Furthermore, the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity. Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching, and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1, but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1. Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals' cognitive abilities. Taken together, our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.

Targeting epigenetic mechanisms in amyloid-β-mediated Alzheimer's pathophysiology: unveiling therapeutic potential

Alzheimer's disease is a prominent chronic neurodegenerative condition characterized by a gradual decline in memory leading to dementia. Growing evidence suggests that Alzheimer's disease is associated with accumulating various amyloid-β oligomers in the brain, influenced by complex genetic and environmental factors. The memory and cognitive deficits observed during the prodromal and mild cognitive impairment phases of Alzheimer's disease are believed to primarily result from synaptic dysfunction. Throughout life, environmental factors can lead to enduring changes in gene expression and the emergence of brain disorders. These changes, known as epigenetic modifications, also play a crucial role in regulating the formation of synapses and their adaptability in response to neuronal activity. In this context, we highlight recent advances in understanding the roles played by key components of the epigenetic machinery, specifically DNA methylation, histone modification, and microRNAs, in the development of Alzheimer's disease, synaptic function, and activity-dependent synaptic plasticity. Moreover, we explore various strategies, including enriched environments, exposure to non-invasive brain stimulation, and the use of pharmacological agents, aimed at improving synaptic function and enhancing long-term potentiation, a process integral to epigenetic mechanisms. Lastly, we deliberate on the development of effective epigenetic agents and safe therapeutic approaches for managing Alzheimer's disease. We suggest that addressing Alzheimer's disease may require distinct tailored epigenetic drugs targeting different disease stages or pathways rather than relying on a single drug.

Astroglial membrane camouflaged Ptbp1 siRNA delivery hinders glutamate homeostasis via SDH/Nrf2 pathway

Polypyrimidine tract-binding protein 1 (PTBP1) regulates numerous alternative splicing events during tumor progression and neurogenesis. Previously, PTBP1 downregulation was reported to convert astrocytes into functional neurons; however, how PTBP1 regulates astrocytic physiology remains unclear. In this study, we revealed that PTBP1 modulated glutamate uptake via ATP1a2, a member of Na+/K+-ATPases, and glutamate transporters in astrocytes. Ptbp1 knockdown altered mitochondrial function and energy metabolism, which involved PTBP1 regulating mitochondrial redox homeostasis via the succinate dehydrogenase (SDH)/Nrf2 pathway. The malfunction of glutamate transporters following Ptbp1 knockdown resulted in enhanced excitatory synaptic transmission in the cortex. Notably, we developed a biomimetic cationic triblock polypeptide system, i.e., polyethylene glycol44-polylysine30-polyleucine10 (PEG44-PLL30-PLLeu10) with astrocytic membrane coating to deliver Ptbp1 siRNA in vitro and in vivo, which approach allowed Ptbp1 siRNA to efficiently cross the blood-brain barrier and target astrocytes in the brain. Collectively, our findings suggest a framework whereby PTBP1 serves as a modulator in glutamate transport machinery, and indicate that biomimetic methodology is a promising route for in vivo siRNA delivery.

Vegetal memory through the lens of transcriptomic changes - recent progress and future practical prospects for exploiting plant transcriptional memory

Plant memory plays an important role in the efficient and rapid acclimation to a swiftly changing environment. In addition, since plant memory can be inherited, it is also of adaptive and evolutionary importance. The ability of a plant to store, retain, retrieve and delete information on acquired experience is based on cellular, biochemical and molecular networks in the plants. This review offers an up-to-date overview on the formation, types, checkpoints of plant memory based on our current knowledge and focusing on its transcriptional aspects, the transcriptional memory. Roles of long and small non-coding RNAs are summarized in the regulation, formation and the cooperation between the different layers of the plant memory, i.e. in the establishment of epigenetic changes associated with memory formation in plants. The RNA interference mechanisms at the RNA and DNA level and the interplays between them are also presented. Furthermore, this review gives an insight of how exploitation of plant transcriptional memory may provide new opportunities for elaborating promising cost-efficient, and effective strategies to cope with the ever-changing environmental perturbations, caused by climate change. The potentials of plant memory-based methods, such as crop priming, cross acclimatization, memory modification by miRNAs and associative use of plant memory, in the future's agriculture are also discussed.

COT-TT vaccine attenuates cocaine-seeking and cocaine-conditioned place preference in rats

Vaccination active, promising alternative immunological strategy to treat of CUD. Various models of cocaine vaccines have been evaluated in animals and humans with relative success. In this sense, it is necessary to improve or optimize the cocaine vaccines already evaluated. Our laboratory previously reported the efficacy of the tetanus toxoid-conjugated morphine vaccine (M6-TT). The M6-TT vaccine can generate high titers of antibodies and reduce heroin-induced behavioral effects in rodents. So, it would be plausible to assume that if we modify the M6-TT vaccine by changing the hapten and maintaining the rest of the structural elements of the vaccine, we will maintain the properties of the M6-TT vaccine (high antibody titers). The objective of this study was to determine whether the antibodies generated by a tetanus toxoid-conjugated cocaine vaccine (COC-TT) can recognize and capture cocaine and decrease the cocaine-induced reinforcing effects. Male Wistar rats were immunized with the COC-TT. A solid-phase antibody-capture ELISA was used to monitor antibody titer responses after each booster dose in vaccinated animals. The study used cocaine self-administration and place-preference testing to evaluate the cocaine-reinforcing effects. The COC-TT vaccine could generate high levels of anti-cocaine antibodies. The antibodies reduced the cocaine self-administration and cocaine place preference. In addition, they decreased the cocaine-induced Fos protein expression. These findings suggest that the COC-TT vaccine generates a robust immunogenic response capable of reducing the reinforcing effects of cocaine, which supports its possible future use in clinical trials in patients with CUD.

Individualized functional connectome abnormalities obtained using two normative model unveil neurophysiological subtypes of obsessive compulsive disorder

The high heterogeneity observed among patients with obsessive-compulsive disorder (OCD) underscores the need to identify neurophysiological OCD subtypes to facilitate personalized diagnosis and treatment. In this study, our aim was to identify potential OCD subtypes based on individualized functional connectome abnormalities. We recruited a total of 99 patients with OCD and 104 healthy controls (HCs) matched for demographic characteristics. Individualized functional connectome abnormalities were obtained using normative models of functional connectivity strength (FCS) and used as features to unveil OCD subtypes. Sensitivity analyses were conducted to assess the reproducibility and robustness of the clustering outcomes. Patients exhibited significant intersubject heterogeneity in individualized functional connectome abnormalities. Two subtypes with distinct patterns of FCS abnormalities relative to HCs were identified. Subtype 1 patients primarily exhibited significantly decreased FCS in regions including the frontal gyrus, insula, hippocampus, and precentral/postcentral gyrus, whereas subtype 2 patients demonstrated increased FCS in widespread brain regions. When all patients were combined, no significant differences were observed. Additionally, the identified subtypes showed significant differences in age of onset. Furthermore, sensitivity analyses confirmed the reproducibility of our subtyping results. In conclusion, the identified OCD subtypes shed new light on the taxonomy and neurophysiological heterogeneity of OCD.

From brain connectivity to cognitive function: Dissecting the salience network in pediatric BECTS-ESES

BACKGROUND

Benign childhood epilepsy with centrotemporal spikes (BECTS), a common pediatric epilepsy, may lead to cognitive decline when compounded by Electrical Status Epilepticus during Sleep (ESES). Emerging evidence suggests that disruptions in the Salience Network (SN) contribute significantly to the cognitive deficits observed in BECTS-ESES. Our study rigorously investigates the dynamic functional connectivity (dFC) within the SN and its correlation with cognitive impairments in BECTS-ESES, employing advanced neuroimaging and neuropsychological assessments.

METHODS

In this research, 45 patients diagnosed with BECTS-ESES and 55 age-matched healthy controls (HCs) participated. We utilized resting-state functional magnetic resonance imaging (fMRI) and Independent Component Analysis (ICA) to identify three fundamental SN nodes: the right Anterior Insula (rAI), left Anterior Insula (lAI), and the Anterior Cingulate Cortex (ACC). A two-sample t-test facilitated the comparison of dFC between these pivotal regions and other brain areas.

RESULTS

Significantly, the BECTS-ESES group demonstrated increased dFC, particularly between the ACC and the right Middle Occipital Gyrus, and from the rAI to the right Superior Parietal Gyrus and Cerebellum, and from the lAI to the left Postcentral Gyrus. Such dFC augmentations provide neural insights potentially explaining the neuropsychological deficits in BECTS-ESES children. Employing comprehensive neuropsychological evaluations, we mapped these dFC disruptions to specific cognitive impairments encompassing memory, executive functioning, language, and attention. Through multiple regression analysis and path analysis, a preliminary but compelling association was discovered linking dFC disturbances directly to cognitive impairments. These findings underscore the critical role of SN disruptions in BECTS-ESES cognitive dysfunctions.

LIMITATION

Our cross-sectional design and analytic methods preclude definitive mediation models and causal inferences, leaving the precise nature of dFC's mediating role and its direct impact by BECTS-ESES partially unresolved. Future longitudinal and confirmatory studies are needed to comprehensively delineate these associations.

CONCLUSION

Our study heralds dFC within the SN as a vital biomarker for cognitive impairment in pediatric epilepsy, advocating for targeted cognitive-specific interventions in managing BECTS-ESES. The preliminary nature of our findings invites further studies to substantiate these associations, offering profound implications for the prognosis and therapeutic strategies in BECTS-ESES, thereby underlining the importance of this research in the field of pediatric neurology and epilepsy management.

Resting-state dynamic functional connectivity in major depressive disorder: A systematic review

As a novel measure, dynamic functional connectivity (dFC) provides insight into the dynamic nature of brain networks and their interactions in resting-state, surpassing traditional static functional connectivity in pathological conditions such as depression. Since a comprehensive review is still lacking, we then reviewed forty-five eligible papers to explore pathological mechanisms of major depressive disorder (MDD) from perspectives including abnormal brain regions and functional networks, brain state, topological properties, relevant recognition, along with longitudinal studies. Though inconsistencies could be found, common findings are: (1) From different perspectives based on dFC, default-mode network (DMN) with its subregions exhibited a close relation to the pathological mechanism of MDD. (2) With a corrupted integrity within large-scale functional networks and imbalance between them, longer fraction time in a relatively weakly-connected state may be a possible property of MDD concerning its relation with DMN. Abnormal transition frequencies between states were correlated to the severity of MDD. (3) Including dynamic properties in topological network metrics enhanced recognition effect. In all, this review summarized its use for clinical diagnosis and treatment, elucidating the non-stationary of MDD patients' aberrant brain activity in the absence of stimuli and bringing new views into its underlying neuro mechanism.

Impaired 40-Hz and intact hierarchical organization mode of auditory steady-state responses among individuals with clinical high-risk for psychosis

BACKGROUND

Impaired gamma band oscillation, specifically 40-Hz auditory steady state response (ASSR) has been robustly found in schizophrenia, while there is relatively little evidence characterizing the ASSR before full-blown psychosis.

OBJECTIVE

To characterize gamma-band ASSR in populations at clinical high-risk for psychosis (CHR).

METHODS

One hundred and seven CHR subjects and sixty-five healthy control (HC) subjects were included and completed clinical assessments, the ASSR paradigm of electroencephalography (EEG) and cognitive assessments. Both indices of event-related spectrum perturbation (ERSP) and intertrial coherence (ITC) in response to 20-Hz, 30-Hz and 40-Hz click sounds were respectively qualified and compared between these two groups, as well as the relationship to clinical psychopathology and cognitive function was assessed.

RESULTS

At 40-Hz click sounds, ERSP in HC group (1.042 ± 0.047) was statistical significantly increased than that in CHR group (0.873 ± 0.036) (p = 0.005)；at 30-Hz, ERSP in HC group (0.536 ± 0.024) was increased than that in CHR group (0.483 ± 0.019), but the difference was trend statistical significance (p = 0.083)；at 20-Hz, ERSP in HC group (0.452 ± 0.017) was not different significantly from CHR group (0.418 ± 0.013) (p = 0.104). ERSP of the HC group was the highest at 40-Hz click sounds, followed by 30-Hz, and the lowest at 20-Hz. The difference between any two of the three ERSP showed statistical significance (30-Hz vs. 40-Hz: p < 0.001; 20-Hz vs. 40-Hz: p < 0.001；20-Hz vs. 30-Hz: p = 0.003). Similarly, ERSP of the CHR group was the highest at 40-Hz click sounds, followed by 30-Hz, and the lowest at 20-Hz. The difference between any two of these three ERSP showed statistical significance (30-Hz vs. 40-Hz: p < 0.001; 20-Hz vs. 40-Hz: p < 0.001；20-Hz vs. 30-Hz: p = 0.002). A statistically significant small positive correlation of 40-Hz ERSP with signal processing speed score was observed in the HC group (ρ = 0.27, p = 0.029). A statistically significant small negative correlation of 40-Hz ERSP with visual learning score was observed in the CHR group (ρ = -0.22, p = 0.023).

CONCLUSION

Impaired 40-Hz but undamaged hierarchical organization mode of auditory steady state presented in the CHR populations. Abnormal 40 Hz ASSR for CHR might be associated with cognitive functions, such as information processing speed and visual memory.

MicroRNA dysregulation in glutamate and dopamine pathways of schizophrenia: From molecular pathways to diagnostic and therapeutic approaches

Schizophrenia is a complex psychiatric disorder, and genetic and environmental factors have been implicated in its development. Dysregulated glutamatergic and dopaminergic transmission pathways are involved in schizophrenia development. Besides genetic mutations, epigenetic dysregulation has a considerable role in dysregulating molecular pathways involved in schizophrenia. MicroRNAs (miRNAs) are small, non-coding RNAs that target specific mRNAs and inhibit their translation into proteins. As epigenetic factors, miRNAs regulate many genes involved in glutamate and dopamine signaling pathways; thereby, their dysregulation can contribute to the development of schizophrenia. Secretion of specific miRNAs from damaged cells into body fluids can make them one of the ideal non-invasive biomarkers in the early diagnosis of schizophrenia. Also, understanding the molecular mechanisms of miRNAs in schizophrenia pathogenesis can pave the way for developing novel treatments for patients with schizophrenia. In this study, we reviewed the glutamatergic and dopaminergic pathophysiology and highlighted the role of miRNA dysregulation in schizophrenia development. Besides, we shed light on the significance of circulating miRNAs for schizophrenia diagnosis and the recent findings on the miRNA-based treatment for schizophrenia.

Similarities and differences in dynamic properties of brain networks between internet gaming disorder and tobacco use disorder

BACKGROUND

Internet gaming disorder (IGD) and tobacco use disorder (TUD) are two major addiction disorders that result in substantial financial loss. Identifying the similarities and differences between these two disorders is important to understand substance addiction and behavioral addiction. The current study was designed to compare these two disorders utilizing dynamic analysis.

METHOD

Resting-state data were collected from 35 individuals with IGD, 35 individuals with TUD and 35 healthy controls (HCs). Dynamic coactivation pattern analysis was employed to decipher their dynamic patterns.

RESULTS

IGD participants showed decreased coactivation patterns within the default mode network (DMN) and between the DMN and the salience network (SN). The SN showed reduced coactivation patterns with the executive control network (ECN) and DMN, and the ECN showed decreased coactivation patterns with the DMN. In the TUD group, the DMN exhibited decreased coactivation patterns with the SN, the SN exhibited reduced coactivation patterns with the DMN and ECN, and the ECN showed decreased coactivation patterns with the DMN and within the ECN. Furthermore, the triple network model was fitted to the dynamic properties of the two addiction disorders. Decoding analysis results indicated that addiction-related memory and memory retrieval displayed similar dysfunctions in both addictions.

CONCLUSION

The dynamic characteristics of IGD and TUD suggest that there are similarities in the dynamic features between the SN and DMN and differences in the dynamic features between the DMN and ECN. Our results revealed that the two addiction disorders have dissociable brain mechanisms, indicating that future studies should consider these two addiction disorders as having two separate mechanisms to achieve precise treatment for their individualized targets.

Aberrant glutamatergic systems underlying impulsive behaviors: Insights from clinical and preclinical research

Impulsivity is a broad construct that often refers to one of several distinct behaviors and can be measured with self-report questionnaires and behavioral paradigms. Several psychiatric conditions are characterized by one or more forms of impulsive behavior, most notably the impulsive/hyperactive subtype of attention-deficit/hyperactivity disorder (ADHD), mood disorders, and substance use disorders. Monoaminergic neurotransmitters are known to mediate impulsive behaviors and are implicated in various psychiatric conditions. However, growing evidence suggests that glutamate, the major excitatory neurotransmitter of the mammalian brain, regulates important functions that become dysregulated in conditions like ADHD. The purpose of the current review is to discuss clinical and preclinical evidence linking glutamate to separate aspects of impulsivity, specifically motor impulsivity, impulsive choice, and affective impulsivity. Hyperactive glutamatergic activity in the corticostriatal and the cerebro-cerebellar pathways are major determinants of motor impulsivity. Conversely, hypoactive glutamatergic activity in frontal cortical areas and hippocampus and hyperactive glutamatergic activity in anterior cingulate cortex and nucleus accumbens mediate impulsive choice. Affective impulsivity is controlled by similar glutamatergic dysfunction observed for motor impulsivity, except a hyperactive limbic system is also involved. Loss of glutamate homeostasis in prefrontal and nucleus accumbens may contribute to motor impulsivity/affective impulsivity and impulsive choice, respectively. These results are important as they can lead to novel treatments for those with a condition characterized by increased impulsivity that are resistant to conventional treatments.

Simple improvements in vector design afford substantial gains in AAV delivery of aggregation-slowing Aβ variants

Adeno-associated virus (AAV) gene therapy for neurological disease has gained traction due to stunning advances in capsid evolution for CNS targeting. With AAV brain delivery now in focus, conventional improvements in viral expression vectors offer a complementary route for optimizing gene delivery. We previously introduced a novel AAV gene therapy to slow amyloid aggregation in the brain based on neuronal release of an Aβ sequence variant that inhibited fibrilization of wild-type Aβ. Here we explore three coding elements of the virally delivered DNA plasmid in an effort to maximize the production of therapeutic peptide in the brain. We demonstrate that simply replacing the Gaussia luciferase signal peptide with the mouse immunoglobulin heavy chain signal peptide increased release of variant Aβ by ∼5-fold. Sequence modifications within the expressed minigene further increased peptide release by promoting γ-secretase cleavage. Addition of a cytosolic fusion tag compatible with γ-secretase interaction allowed viral transduction to be tracked by immunostaining, independent from the variant Aβ peptide. Collectively these construct modifications increased neuronal production of therapeutic peptide by 10-fold upon intracranial AAV injection of neonatal mice. These findings demonstrate that modest changes in expression vector design can yield substantial gains in AAV efficiency for therapeutic applications.

Dye-sensitized lanthanide-doped upconversion nanoprobe for enhanced sensitive detection of Fe3+ in human serum and tap water

Iron ion (Fe3+) detection is crucial for human health since it plays a crucial role in many physiological activities. In this work, a novel Schiff-base functionalized cyanine derivative (CyPy) was synthesized, which was successfully assembled on the surface of upconversion nanoparticles (UCNPs) through an amphiphilic polymer encapsulation method. In the as-designed nanoprobe, CyPy, a recognizer of Fe3+, is served as energy donor and β-NaYF4:Yb,Er upconversion nanoparticles are adopted as energy acceptor. As a result, a 93-fold enhancement of upconversion luminescence is achieved. The efficient energy transfer from CyPy to β-NaYF4:Yb,Er endows the nanoprobe a high sensitivity for Fe3+ in water with a low detection limit of 0.21 μM. Moreover, the nanoprobe has been successfully applied for Fe3+ determination in human serum and tap water samples with recovery ranges of 95 %-105 % and 97 %-106 %, respectively. Moreover, their relative standard deviations are all below 3.72 %. This work provides a sensitive and efficient methodology for Fe3+ detection in clinical and environmental testing.

Effects of four-week intranasal oxytocin administration on large-scale brain networks in older adults

Oxytocin (OT) is a crucial modulator of social cognition and behavior. Previous work primarily examined effects of acute intranasal oxytocin administration (IN-OT) in younger males on isolated brain regions. Not well understood are (i) chronic IN-OT effects, (ii) in older adults, (iii) on large-scale brain networks, representative of OT's wider-ranging brain mechanisms. To address these research gaps, 60 generally healthy older adults (mean age = 70.12 years, range = 55-83) were randomly assigned to self-administer either IN-OT or placebo twice daily via nasal spray over four weeks. Chronic IN-OT reduced resting-state functional connectivity (rs-FC) of both the right insula and the left middle cingulate cortex with the salience network but enhanced rs-FC of the left medial prefrontal cortex with the default mode network as well as the left thalamus with the basal ganglia-thalamus network. No significant chronic IN-OT effects were observed for between-network rs-FC. However, chronic IN-OT increased selective rs-FC of the basal ganglia-thalamus network with the salience network and the default mode network, indicative of more specialized, efficient communication between these networks. Directly comparing chronic vs. acute IN-OT, reduced rs-FC of the right insula with the salience network and between the default mode network and the basal ganglia-thalamus network, and greater selective rs-FC of the salience network with the default mode network and the basal ganglia-thalamus network, were more pronounced after chronic than acute IN-OT. Our results delineate the modulatory role of IN-OT on large-scale brain networks among older adults.

Non-ionotropic voltage-gated calcium channel signaling

Voltage-gated calcium channels (VGCCs) are the major conduits for calcium ions (Ca2+) within excitable cells. Recent studies have highlighted the non-ionotropic functionality of VGCCs, revealing their capacity to activate intracellular pathways independently of ion flow. This non-ionotropic signaling mode plays a pivotal role in excitation-coupling processes, including gene transcription through excitation-transcription (ET), synaptic transmission via excitation-secretion (ES), and cardiac contraction through excitation-contraction (EC). However, it is noteworthy that these excitation-coupling processes require extracellular calcium (Ca2+) and Ca2+ occupancy of the channel ion pore. Analogous to the "non-canonical" characterization of the non-ionotropic signaling exhibited by the N-methyl-D-aspartate receptor (NMDA), which requires extracellular Ca2+ without the influx of ions, VGCC activation requires depolarization-triggered conformational change(s) concomitant with Ca2+ binding to the open channel. Here, we discuss the contributions of VGCCs to ES, ET, and EC coupling as Ca2+ binding macromolecules that transduces external stimuli to intracellular input prior to elevating intracellular Ca2+. We emphasize the recognition of calcium ion occupancy within the open ion-pore and its contribution to the excitation coupling processes that precede the influx of calcium. The non-ionotropic activation of VGCCs, triggered by the upstroke of an action potential, provides a conceptual framework to elucidate the mechanistic aspects underlying the microseconds nature of synaptic transmission, cardiac contractility, and the rapid induction of first-wave genes.

Advances in targeted therapy of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignant tumor originating in the bile duct and its branching epithelium. Due to its high heterogeneity, there are no specific clinical indications at the early stage, the diagnosis is often in advanced CCA. With surgical resection, the 5-year postoperative survival rate (long-term survival rate) is very poor. The regimen of gemcitabine combined with platinum has been used as the first-line chemotherapy for advanced patients. In recent years, targeted therapy for a variety of malignant tumors has made great progress, showing good efficacy and safety in advanced CCA. However, the current targeted therapy of CCA still has many challenges, such as adverse reactions, drug resistance, and individual differences. Therefore, the researches need to further explore the targeted therapy mechanism of CCA malignancies in depth, develop more effective and safe drugs, and accurately formulate plans based on patient characteristics to further improve patient prognosis in the future. This article reviews the recent progress of targeted therapy for CCA, aiming to provide a strategy for the research and clinical work of targeted therapy for CCA.

M1-type polarized macrophage contributes to brain damage through CXCR3.2/CXCL11 pathways after RGNNV infection in grouper

The vertebrate central nervous system (CNS) is the most complex system of the body. The CNS, especially the brain, is generally regarded as immune-privileged. However, the specialized immune strategies in the brain and how immune cells, specifically macrophages in the brain, respond to virus invasion remain poorly understood. Therefore, this study aimed to examine the potential immune response of macrophages in the brain of orange-spotted groupers (Epinephelus coioides) following red-spotted grouper nervous necrosis virus (RGNNV) infection. We observed that RGNNV induced macrophages to produce an inflammatory response in the brain of orange-spotted grouper, and the macrophages exhibited M1-type polarization after RGNNV infection. In addition, we found RGNNV-induced macrophage M1 polarization via the CXCR3.2- CXCL11 pathway. Furthermore, we observed that RGNNV triggered M1 polarization in macrophages, resulting in substantial proinflammatory cytokine production and subsequent damage to brain tissue. These findings reveal a unique mechanism for brain macrophage polarization, emphasizing their role in contributing to nervous tissue damage following viral infection in the CNS.

The perinucleolar compartment: structure, function, and utility in anti-cancer drug development

The perinucleolar compartment (PNC) was initially identified as a nuclear structure enriched for the polypyrimidine tract-binding protein. Since then, the PNC has been implicated in carcinogenesis. The prevalence of this compartment is positively correlated with disease progression in various types of cancer, and its expression in primary tumors is linked to worse patient outcomes. Using the PNC as a surrogate marker for anti-cancer drug efficacy has led to the development of a clinical candidate for anti-metastasis therapies. The PNC is a multicomponent nuclear body situated at the periphery of the nucleolus. Thus far, several non-coding RNAs and RNA-binding proteins have been identified as the PNC components. Here, we summarize the current understanding of the structure and function of the PNC, as well as its recurrent links to cancer progression and metastasis.

Effects and mechanisms of anterior thalamus nucleus deep brain stimulation for epilepsy: A scoping review of preclinical studies

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a safe and effective intervention for the treatment of certain forms of epilepsy. In preclinical models, electrical stimulation of the ANT has antiepileptogenic effects but its underlying mechanisms remain unclear. In this review, we searched multiple databases for studies that described the effects and mechanisms of ANT low or high frequency stimulation (LFS or HFS) in models of epilepsy. Out of 289 articles identified, 83 were pooled for analysis and 34 were included. Overall, ANT DBS was most commonly delivered at high frequency to rodents injected with kainic acid, pilocarpine, or pentylenetetrazole. In most studies, this therapy increased the latency to the first spontaneous seizure and reduced the frequency of seizures by 20%-80%. Electrophysiology data suggested that DBS reduces the severity of electrographic seizures, decreases the duration and increases the threshold of afterdischarges, reduces the power of low-frequency and increase the power high-frequency bands. Mechanistic studies revealed that ANT DBS leads to a series of short- and long-term changes at multiple levels. Some of its anticonvulsant effects were proposed to occur via the modulation of serotonergic and adenosinergic transmission. The latter seems to be derived from the downregulation of adenosine kinase (ADK). ANT DBS was also shown to increase hippocampal levels of lactate, alter the expression of genes involved in calcium signaling, synaptic glutamate, and the NOD-like receptor signaling pathway. When delivered during status epilepticus or following the injection of convulsant agents, DBS was found to reduce the expression of proinflammatory cytokines and apoptosis. When administered chronically, ANT DBS increased the expression of proteins involved in axonal guidance, changed functional connectivity in limbic circuits, and increased the number of hippocampal cells in epileptic animals, suggesting a neuroprotective effect.

Brain activity during working memory in patients with autoimmune Addison's disease

Autoimmune Addison's disease (AAD) is treated with daily oral hormone replacements for cortisol and aldosterone. The current treatment is sub-optimal, and frequently results in supra- and infra-physiological cortisol levels that might negatively affect the brain and cognitive functioning. It is currently unclear if the brains of these patients need to be better protected. The present study investigates brain function during working memory in young adults with AAD compared to healthy controls. All participants (56 AAD (33 females), 62 controls (39 females), 19-43 years), underwent MRI brain scanning while performing a visuo-spatial and verbal working memory task. No main group differences in accuracy, reaction time or brain activity during the tasks were found. These findings suggest that patients perform equal to controls, and achieve similar levels of brain activity during working memory. However, variations in the patient population may have confounded this outcome. Controlled studies on larger cohorts are therefore needed to confirm these findings and test if having AAD affects the brain on the long term.

The impact of insomnia on brain networks topology in depressed patients: A resting-state fMRI study

OBJECTIVE

Depression and insomnia frequently co-occur, but the neural mechanisms between patients with varying degrees of these conditions are not fully understood. The specific topological features and connectivity patterns of this co-morbidity have not been extensively studied. This study aimed to investigate the topological characteristics of topological characteristics and functional connectivity of brain networks in depressed patients with insomnia.

METHODS

Resting-state functional magnetic resonance imaging data from 32 depressed patients with a high level of insomnia (D-HI), 35 depressed patients with a low level of insomnia (D-LI), and 81 healthy controls (HC) were used to investigate alterations in brain topological organization functional networks. Nodal and global properties were analyzed using graph-theoretic techniques, and network-based statistical analysis was employed to identify changes in brain network functional connectivity.

RESULTS

Compared to the HC group, both the D-HI and D-LI groups showed an increase in the global efficiency (Eglob) values, local efficiency (Eloc) was decreased in the D-HI group, and Lambda and shortest path length (Lp) values were decreased in the D-LI group. At the nodal level, the right parietal nodal clustering coefficient (NCp) values were reduced in D-HI and D-LI groups compared to those in HC. The functional connectivity of brain networks in patients with D-HI mainly involves default mode network (DMN)-cingulo-opercular network (CON), DMN-visual network (VN), DMN-sensorimotor network (SMN), and DMN-cerebellar network (CN), while that in patients with D-LI mainly involves SMN-CON, SMN-SMN, SMN-VN, and SMN-CN. The values of the connection between the midinsula and postoccipital gyrus was negatively correlated with scores for early awakening in D-HI.

CONCLUSION

These findings may contribute to our understanding of the underlying neuropsychological mechanisms in depressed patients with insomnia.

Brain-Derived neurotrophic factor and inflammatory biomarkers are unaffected by acute and chronic intermittent hypoxic-hyperoxic exposure in geriatric patients: a randomized controlled trial

BACKGROUND

Animal and human studies have shown that exposure to hypoxia can increase brain-derived neurotrophic factor (BDNF) protein transcription and reduce systematic inflammatory cytokine response. Therefore, the aim of this study was to investigate the acute and chronic effects of intermittent hypoxic-hyperoxic exposure (IHHE) prior to aerobic exercise on BDNF, interleukin-6 (IL-6), and C-reactive protein (CRP) blood levels in geriatric patients.

PATIENTS AND METHODS

Twenty-five geriatric patients (83.1 ± 5.0 yrs, 71.1 ± 10.0 kg, 1.8 ± 0.9 m) participated in a placebo-controlled, single-blinded trial and were randomly assigned to either an intervention (IG) or control group (CG) performing an aerobic cycling training (17 sessions, 20 min·session-1, 3 sessions·week-1). Prior to aerobic cycling exercise, the IG was additionally exposed to IHHE for 30 min, whereas the CG received continuous normoxic air. Blood samples were taken immediately before (pre-exercise) and 10 min (post-exercise) after the first session as well as 48 h (post-training) after the last session to determine serum (BDNFS) and plasma BDNF (BDNFP), IL-6, and CRP levels. Intervention effects were analyzed using a 2 x 2 analysis of covariance with repeated measures. Results were interpreted based on effect sizes with a medium effect considered as meaningful (ηp2 ≥ 0.06, d ≥ 0.5).

RESULTS

CRP was moderately higher (d = 0.51) in the CG compared to the IG at baseline. IHHE had no acute effect on BDNFS (ηp2 = 0.01), BDNFP (ηp2 < 0.01), BDNF serum/plasma-ratio (ηp2 < 0.01), IL-6 (ηp2 < 0.01), or CRP (ηp2 = 0.04). After the 6-week intervention, an interaction was found for BDNF serum/plasma-ratio (ηp2 = 0.06) but not for BDNFS (ηp2 = 0.04), BDNFP (ηp2 < 0.01), IL-6 (ηp2 < 0.01), or CRP (ηp2 < 0.01). BDNF serum/plasma-ratio increased from pre-exercise to post-training (d = 0.67) in the CG compared to the IG (d = 0.51). A main effect of time was found for BDNFP (ηp2 = 0.09) but not for BDNFS (ηp2 = 0.02). Within-group post-hoc analyses revealed a training-related reduction in BDNFP in the IG and CG by 46.1% (d = 0.73) and 24.7% (d = 0.57), respectively.

CONCLUSION

The addition of 30 min IHHE prior to 20 min aerobic cycling seems not to be effective to increase BDNFS and BDNFP or to reduce IL-6 and CRP levels in geriatric patients after a 6-week intervention.The study was retrospectively registered at drks.de (DRKS-ID: DRKS00025130).

Alcohol, flexible behavior, and the prefrontal cortex: Functional changes underlying impaired cognitive flexibility

Cognitive flexibility enables individuals to alter their behavior in response to changing environmental demands, facilitating optimal behavior in a dynamic world. The inability to do this, called behavioral inflexibility, is a pervasive behavioral phenotype in alcohol use disorder (AUD), driven by disruptions in cognitive flexibility. Research has repeatedly shown that behavioral inflexibility not only results from alcohol exposure across species but can itself be predictive of future drinking. Like many high-level executive functions, flexible behavior requires healthy functioning of the prefrontal cortex (PFC). The scope of this review addresses two primary themes: first, we outline tasks that have been used to investigate flexibility in the context of AUD or AUD models. We characterize these based on the task features and underlying cognitive processes that differentiate them from one another. We highlight the neural basis of flexibility measures, focusing on the PFC, and how acute or chronic alcohol in humans and non-human animal models impacts flexibility. Second, we consolidate findings on the molecular, physiological and functional changes in the PFC elicited by alcohol, that may contribute to cognitive flexibility deficits seen in AUD. Collectively, this approach identifies several key avenues for future research that will facilitate effective treatments to promote flexible behavior in the context of AUD, to reduce the risk of alcohol related harm, and to improve outcomes following AUD. This article is part of the Special Issue on "PFC circuit function in psychiatric disease and relevant models".

Recovering skin-nerve interaction by nanoscale metal-organic framework for diabetic ulcers healing

Skin-nerve interaction plays an important role in promoting wound healing. However, in diabetic ulcers (DUs), the diabetic periphery neuropathy and excessive levels of reactive oxygen species (ROS) block skin-nerve interaction and further impede the DUs healing. Herein, we developed a nanoscale metal-organic framework loaded with nerve growth factor (NGF/Ce-UiO-66, denoted NGF/CU) for the treatment of DUs. The Ce-UiO-66 (CU) was applied as an antioxidant to scavenge ROS and reduce the inflammatory response while the NGF aided in the recovery of cutaneous nerves to further promote DUs healing. Both in vitro and in vivo experiments revealed the effective ability of NGF/CU for DUs healing. Subsequent RNA sequencing analysis revealed the mechanism that NGF/CU can improve wound healing by inhibiting the NF-κB signaling pathway and recovering the neuroendocrine system of the skin. This strategy of nerve regulation will provide more ideas for the treatment of DUs and other organ injuries.

Neural correlates of anhedonia in young adults with subthreshold depression: A graph theory approach for cortical-subcortical structural covariance

BACKGROUND

Anhedonia is an enduring symptom of subthreshold depression (StD) and predict later onset of major depressive disorder (MDD). Brain structural covariance describes the inter-regional distribution of morphological changes compared to healthy controls (HC) and reflects brain maturation and disease progression. We investigated neural correlates of anhedonia from the structural covariance.

METHODS

T1-weighted brain magnetic resonance images were acquired from 79 young adults (26 StD, 30 MDD, and 23 HC). Intra-individual structural covariance networks of 68 cortical surface area (CSAs), 68 cortical thicknesses (CTs), and 14 subcortical volumes were constructed. Group-level hubs and principal edges were defined using the global and regional graph metrics, compared between groups, and examined for the association with anhedonia severity.

RESULTS

Global network metrics were comparable among the StD, MDD, and HC. StD exhibited lower centralities of left pallidal volume than HC. StD showed higher centralities than HC in the CSAs of right rostral anterior cingulate cortex (ACC) and pars triangularis, and in the CT of left pars orbitalis. Less anhedonia was associated with higher centralities of left pallidum and right amygdala, higher edge betweenness centralities in the structural covariance (EBSC) of left postcentral gyrus-parahippocampal gyrus and LIPL-right amygdala. More anhedonia was associated with higher centralities of left inferior parietal lobule (LIPL), left postcentral gyrus, left caudal ACC, and higher EBSC of LIPL-left postcentral gyrus, LIPL-right lateral occipital gyrus, and left caudal ACC-parahippocampal gyrus.

LIMITATIONS

This study has a cross-sectional design.

CONCLUSIONS

Structural covariance of brain morphologies within the salience and limbic networks, and among the salience-limbic-default mode-somatomotor-visual networks, are possible neural correlates of anhedonia in depression.

Multifunctional Tetrode-like Drug delivery, Optical stimulation, and Electrophysiology (Tetro-DOpE) probes

Having reliable tools for recording and manipulating circuit activity are essential to understand the complex patterns of neural dynamics that underlie brain function. We present Tetro-DOpE (Tetrode-like Drug delivery, Optical stimulation, and Electrophysiology) probes that can simultaneously record and manipulate neural activity in behaving rodents. We fabricated thin multifunctional fibers (<50 μm) using the scalable convergence thermal drawing process. Then, the thin fibers are bundled, similar to tetrode fabrication, to produce Tetro-DOpE probes. We demonstrated the multifunctionality (i.e., electrophysiology, optical stimulation, and drug delivery) of our probe in head-fixed behaving mice. Furthermore, we assembled a six-shank probe mounted on a microdrive which enabled stable recordings of over months when chronically implanted in freely behaving mice. These in vivo experiments demonstrate the potential of customizable, low cost, and accessible multifunctional Tetro-DOpE probes for investigation of neural circuitry in behaving animals.

Structural changes shaping the Drosophila ellipsoid body ER-neurons during development and aging

The ellipsoid body (EB) of the insect brain performs pivotal functions in controlling navigation. Input and output of the EB is provided by multiple classes of R-neurons (now referred to as ER-neurons) and columnar neurons which interact with each other in a stereotypical and spatially highly ordered manner. The developmental mechanisms that control the connectivity and topography of EB neurons are largely unknown. One indispensable prerequisite to unravel these mechanisms is to document in detail the sequence of events that shape EB neurons during their development. In this study, we analyzed the development of the Drosophila EB. In addition to globally following the ER-neuron and columnar neuron (sub)classes in the spatial context of their changing environment we performed a single cell analysis using the multi-color flip out (MCFO) system to analyze the developmental trajectory of ER-neurons at different pupal stages, young adults (4d) and aged adults (∼60d). We show that the EB develops as a merger of two distinct elements, a posterior and anterior EB primordium (prEBp and prEBa, respectively. ER-neurons belonging to different subclasses form growth cones and filopodia that associate with the prEBp and prEBa in a pattern that, from early pupal stages onward, foreshadows their mature structure. Filopodia of all ER-subclasses are initially much longer than the dendritic and terminal axonal branches they give rise to, and are pruned back during late pupal stages. Interestingly, extraneous branches, particularly significant in the dendritic domain, are a hallmark of ER-neuron structure in aged brains. Aging is also associated with a decline in synaptic connectivity from columnar neurons, as well as upregulation of presynaptic protein (Brp) in ER-neurons. Our findings advance the EB (and ER-neurons) as a favorable system to visualize and quantify the development and age-related decline of a complex neuronal circuitry.

Dopaminergic system and neurons: Role in multiple neurological diseases

The dopaminergic system is a complex and powerful neurotransmitter system in the brain. It plays an important regulatory role in motivation, reward, cognition, and motor control. In recent decades, research in the field of the dopaminergic system and neurons has increased exponentially and is gradually becoming a point of intervention in the study and understanding of a wide range of neurological diseases related to human health. Studies have shown that the dopaminergic system and neurons are involved in the development of many neurological diseases (including, but not limited to Parkinson's disease, schizophrenia, depression, attention deficit hyperactivity disorder, etc.) and that dopaminergic neurons either have too much stress or too weak function in the dopaminergic system can lead to disease. Therefore, targeting dopaminergic neurons is considered key to treating these diseases. This article provides a comprehensive review of the dopaminergic system and neurons in terms of brain region distribution, physiological function and subtypes of dopaminergic neurons, as well as the role of the dopaminergic system and neurons in a variety of diseases.

Dissociation of focal and large-scale inhibitory functions in the older adults: A multimodal MRI study

BACKGROUND

The decline of inhibitory in cognitive aging is linked to reduced cognitive and mental capacities in older adults. However, this decline often shows inconsistent clinical presentations, suggesting varied impacts on different inhibition-related tasks. Inhibitory control, a multifaceted construct, involves various types of inhibition. Understanding these components is crucial for comprehending how aging affects inhibitory functions. Our research investigates the influences of aging on large-scale and focal-scale inhibitory and examines the relationship with brain markers.

METHODS

We examined the impact of aging on inhibitory in 18 younger (20-35 years) and 17 older adults (65-85 years) using focal and large-scale inhibition tasks. The Gabor task assessed focal-scale inhibition, while the Stop Signal Task (SST) evaluated large-scale inhibition. Participants underwent neuropsychological assessments and MRI scans, including magnetic resonance spectroscopy (MRS) and structural and resting fMRI.

RESULTS

Older adults exhibited a marked decline in inhibitory function, with slower SST responses indicating compromised large-scale inhibition. Conversely, the Gabor task showed no significant age-related changes. MRS findings revealed decreased levels of GABA, glutamate, glutamine, and NAA in the pre-SMA, correlating with observed large-scale inhibition in older adults. Additionally, pre-SMA seed-based functional connectivity analysis showed reduced brain network connections in older adults, potentially contributing to inhibitory control deficits.

CONCLUSIONS

Our study elucidates the differential effects of aging on inhibitory functions. While large-scale inhibition is more vulnerable to aging, focal-scale inhibition is relatively preserved. These findings highlight the importance of targeted cognitive interventions and underscore the necessity of a multifaceted approach in aging research.

Metacognition of perceptual resolution across and around the visual field

Do people have accurate metacognition of non-uniformities in perceptual resolution across (i.e., eccentricity) and around (i.e., polar angle) the visual field? Despite its theoretical and practical importance, this question has not yet been empirically tested. This study investigated metacognition of perceptual resolution by guessing patterns during a degradation (i.e., loss of high spatial frequencies) localization task. Participants localized the degraded face among the nine faces that simultaneously appeared throughout the visual field: fovea (fixation at the center of the screen), parafovea (left, right, above, and below fixation at 4° eccentricity), and periphery (left, right, above, and below fixation at 10° eccentricity). We presumed that if participants had accurate metacognition, in the absence of a degraded face, they would exhibit compensatory guessing patterns based on counterfactual reasoning ("The degraded face must have been presented at locations with lower perceptual resolution, because if it were presented at locations with higher perceptual resolution, I would have easily detected it."), meaning that we would expect more guess responses for locations with lower perceptual resolution. In two experiments, we observed guessing patterns that suggest that people can monitor non-uniformities in perceptual resolution across, but not around, the visual field during tasks, indicating partial in-the-moment metacognition. Additionally, we found that global explicit knowledge of perceptual resolution is not sufficient to guide in-the-moment metacognition during tasks, which suggests a dissociation between local and global metacognition.

A structural atlas of druggable sites on Nav channels

Voltage-gated sodium (Nav) channels govern membrane excitability by initiating and propagating action potentials. Consistent with their physiological significance, dysfunction, or mutations in these channels are associated with various channelopathies. Nav channels are thereby major targets for various clinical and investigational drugs. In addition, a large number of natural toxins, both small molecules and peptides, can bind to Nav channels and modulate their functions. Technological breakthrough in cryo-electron microscopy (cryo-EM) has enabled the determination of high-resolution structures of eukaryotic and eventually human Nav channels, alone or in complex with auxiliary subunits, toxins, and drugs. These studies have not only advanced our comprehension of channel architecture and working mechanisms but also afforded unprecedented clarity to the molecular basis for the binding and mechanism of action (MOA) of prototypical drugs and toxins. In this review, we will provide an overview of the recent advances in structural pharmacology of Nav channels, encompassing the structural map for ligand binding on Nav channels. These findings have established a vital groundwork for future drug development.

Nitric oxide-signalling affects panic-like defensive behaviour and defensive antinociception neuromodulation in the prelimbic cerebral cortex

RATIONALE

The prelimbic division (PrL) of the medial prefrontal cortex (mPFC) is a key structure in panic.

OBJECTIVES

To evaluate the role of nitric oxide (NO) in defensive behaviour and antinociception.

METHODS

Either Nω-propyl-L-arginine (NPLA) or Carboxy-PTIO was microinjected in the PrL cortex, followed by hypothalamic treatment with bicuculline. The exploratory behaviours, defensive reactions and defensive antinociception were recorded. Encephalic c-Fos protein was immunolabelled after escape behaviour.

RESULTS

NPLA (an inhibition of nNOs) decreased panic-like responses and innate fear-induced antinociception. The c-PTIO (a membrane-impermeable NO scavenger) decreased the escape behaviour. PrL cortex pre-treatment with c-PTIO at all doses decreased defensive antinociception. c-Fos protein was labelled in neocortical areas, limbic system, and mesencephalic structures.

CONCLUSION

The NPLA and c-PTIO in the PrL/mPFC decreased the escape behaviour and defensive antinociception organised by medial hypothalamic nuclei. The oriented escape behaviour recruits neocortical areas, limbic system, and mesencephalic structures. These findings suggest that the organisation of defensive antinociception recruits NO-signalling mechanisms within the PrL cortex. Furthermore, the present findings also support the role of NO as a retrograde messenger in the PrL cortex during panic-like emotional reactions.

The unique face of comorbid anxiety and depression: Increased frontal, insula and cingulate cortex response during Pavlovian fear-conditioning

BACKGROUND

Dysregulation of fear processing through altered sensitivity to threat is thought to contribute to the development of anxiety disorders and major depressive disorder (MDD). However, fewer studies have examined fear processing in MDD than in anxiety disorders. The current study used propensity matching to examine the hypothesis that comorbid MDD and anxiety (AnxMDD) shows greater neural correlates of fear processing than MDD, suggesting that the co-occurrence of AnxMDD is exemplified by exaggerated defense related processes.

METHODS

195 individuals with MDD (N = 65) or AnxMDD (N = 130) were recruited from the community and completed multi-level assessments, including a Pavlovian fear learning task during functional imaging. Visual images paired with threat (conditioned stimuli: CS+) were compared to stimuli not paired with threat (CS-).

RESULTS

MDD and AnxMDD showed significantly different patterns of activation for CS+ vs CS- in the dorsal anterior insula/inferior frontal gyrus (partial eta squared; ηp2 = 0.02), dorsolateral prefrontal cortex (ηp2 = 0.01) and dorsal anterior/mid cingulate cortex (ηp2 = 0.01). These differences were driven by greater activation to the CS+ in AnxMDD versus MDD.

LIMITATIONS

Limitations include the cross-sectional design, a scream US rather than shock and half the number of MDD as AnxMDD participants.

CONCLUSIONS

AnxMDD showed a pattern of increased activation in regions identified with fear processing. Effects were consistently driven by threat, further suggesting fear signaling as the emergent target process. Differences emerged in regions associated with salience processing, attentional orienting/conflict, self-relevant processing and executive functioning in comorbid anxiety and depression, thereby highlighting potential treatment targets for this prevalent and treatment resistant group.

Integrated approach to reducing polypharmacy in older people: exploring the role of oxidative stress and antioxidant potential therapy

Increased life expectancy, attributed to improved access to healthcare and drug development, has led to an increase in multimorbidity, a key contributor to polypharmacy. Polypharmacy is characterised by its association with a variety of adverse events in the older persons. The mechanisms involved in the development of age-related chronic diseases are largely unknown; however, altered redox homeostasis due to ageing is one of the main theories. In this context, the present review explores the development and interaction between different age-related diseases, mainly linked by oxidative stress. In addition, drug interactions in the treatment of various diseases are described, emphasising that the holistic management of older people and their pathologies should prevail over the individual treatment of each condition.

Effects of adolescent alcohol exposure on oligodendrocyte lineage cells and myelination in mice: Age and subregion differences

Adolescence is an important phase for the structural and functional development of the brain. The immaturity of adolescent brain development is associated with high susceptibility to exogenous disturbances, including alcohol. In this study, the acquisition of conditioned place preference (CPP) in adolescent mice by alcohol (2 g/kg) and the parvalbumin-positive interneurons (PV+ interneurons), oligodendrocyte lineage cells (OPCs), and myelination in the medial prefrontal cortex (mPFC) were assessed. We aim to determine the age- and subregional-specificity of the effects of alcohol. Alcohol (2 g/kg) was injected intraperitoneally on even days, and saline was injected intraperitoneally on odd days. The control group received a continuous intraperitoneal injection with saline. Differences in alcohol-induced CPP acquisition were assessed, followed by immunohistochemical staining. The results showed a pronounced CPP acquisition in 4- and 5-week-old mice. In the mPFC, there were reduced PV+ interneurons and OPCs in 3-week-old mice and reduced oligodendrocyte numbers in 4-week-old mice. The 5-week-old mice showed impaired myelination and a decrease in the number of PV+ interneurons, mature oligodendrocytes, and OPCs in the mPFC. Since the alterations in 5-week-old mice are more pronounced, we further explored the mPFC-associated subregional-specificity. In the alcohol-exposed mice, the oligodendrocyte numbers were decreased in the anterior cingulate cortex (ACC), PV+ interneuron numbers were declined in the prelimbic cortex (PL), and the number of oligodendrocytes, PV+ interneurons, and OPCs was also decreased with impaired myelination in the infralimbic cortex (IL). Our data suggest that adolescent alcohol exposure notably affected the acquisition of CPP, myelin formation, and the counts of PV+ interneurons, mature oligodendrocytes, and OPCs in the mPFC in 5-week-old mice. Also, the IL subregion was the worst-affected subregion of the mPFC in alcohol-exposed 5-week-old mice. It reveals that the effects of alcohol on adolescence and its mPFC myelination show obvious age- and subregional-specificity.