Decoding Saccade Intention From Primate Prefrontal Cortical Local Field Potentials Using Spectral, Spatial, and Temporal Dimensionality Reduction

Most invasive Brain Computer Interfaces (iBCIs) use spike and Local Field Potentials (LFPs) from the motor or parietal cortices to decode movement intentions. It has been debated whether harvesting signals from other brain areas that encode global cognitive variables, such as the allocation of attention and eye movement goals in a variety of spatial reference frames, may improve the outcome of iBCIs. Here, we explore the ability of LFP signals, sampled from the lateral prefrontal cortex (LPFC) of macaque monkeys, to encode eye-movement intention during the pre-movement fixation period of a delayed saccade task. We use spectral dimensionality reduction to examine the spatiotemporal properties of the extracted non-rhythmic broadband activity and explore its usefulness in decoding saccade goals. The dynamics of the broadband signal in low spatial dimensions across the pre-movement fixation period uncovered saccade target separation; its discriminative potential was confirmed using support vector machine classifications. These findings reveal that broadband LFP from the LPFC can be used to decode intended saccade target location during pre-movement periods. We further provide a general workflow that can be implemented in iBCIs and it is relatively robust to the loss of spikes in individual electrodes.

In Vitro Conversion Assays Diagnostic for Neurodegenerative Proteinopathies

BACKGROUND

In vitro conversion assays, including real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA) techniques, were first developed to study the conversion process of the prion protein to its misfolded, disease-associated conformation. The intrinsic property of prion proteins to propagate their misfolded structure was later exploited to detect subfemtogram quantities of the misfolded protein present in tissues and fluids from humans and animals with transmissible spongiform encephalopathies. Currently, conversion assays are used clinically as sensitive and specific diagnostic tools for antemortem diagnosis of prion disease.

CONTENT

In vitro conversion assays are now being applied to the development of diagnostics for related neurodegenerative diseases, including detection of misfolded α-synuclein in Parkinson disease, misfolded amyloid-β in Alzheimer disease, and misfolded tau in Pick disease. Like the predicate prion protein in vitro conversion diagnostics, these assays exploit the ability of endogenously misfolded proteins to induce misfolding and aggregation of their natively folded counterpart in vitro. This property enables biomarker detection of the underlying protein pathology. Herein, we review RT-QuIC and PMCA for (a) prion-, (b) α-synuclein-, (c) amyloid-β-, and (d) tau-opathies.

SUMMARY

Although already in routine clinical use for the detection of transmissible spongiform encephalopathies, in vitro conversion assays for other neurodegenerative disorders require further development and evaluation of diagnostic performance before consideration for clinical implementation.

Dopaminergic Projections From the Ventral Tegmental Area to the Nucleus Accumbens Modulate Sevoflurane Anesthesia in Mice

The role of the dopaminergic pathway in general anesthesia and its potential mechanisms are still unknown. In this study, we usedc-Fos staining combined with calcium fiber photometry recording to explore the activity of ventral tegmental area (VTA) dopaminergic neurons(VTA-DA) and nucleus accumbens (NAc) neurons during sevoflurane anesthesia. A genetically encoded dopamine (DA) sensor was used to investigate thefunction of the NAc in sevoflurane anesthesia. Chemogenetics and optogenetics were used to explore the role of the VTA-DA in sevofluraneanesthesia. Electroencephalogram (EEG) spectra, time of loss of righting reflex (LORR) and recovery of righting reflex (RORR) were recorded asassessment indicators. We found that VTA-DA and NAc neurons were inhibited during the induction period and were activated during the recoveryperiod of sevoflurane anesthesia. The fluorescence signals of dopamine decreased in the induction of and increased in the emergence from sevoflurane anesthesia.Activation of VTA-DA and the VTA^DA-NAc pathway delayed the induction and facilitated the emergence accompanying with thereduction of delta band and the augmentation of the gamma band. These data demonstrate that VTA-DA neurons play a critical role in modulating sevofluraneanesthesia via the VTA^DA-NAc pathway.

In silico annotation of unreviewed acetylcholinesterase (AChE) in some lepidopteran insect pest species reveals the causes of insecticide resistance

Lepidoptera is the second most diverse insect order outnumbered only by the Coeleptera. Acetylcholinesterase (AChE) is the major target site for insecticides. Extensive use of insecticides, to inhibit the function of this enzyme, have resulted in the development of insecticide resistance. Complete knowledge of the target proteins is very important to know the cause of resistance. Computational annotation of insect acetylcholinesterase can be helpful for the characterization of this important protein. Acetylcholinesterase of fourteen lepidopteran insect pest species was annotated by using different bioinformatics tools. AChE in all the species was hydrophilic and thermostable. All the species showed lower values for instability index except L. orbonalis, S. exigua and T. absoluta. Highest percentage of Arg, Asp, Asn, Gln and Cys were recorded in P. rapae. High percentage of Cys and Gln might be reason for insecticide resistance development in P. rapae. Phylogenetic analysis revealed the AChE in T. absoluta, L. orbonalis and S. exigua are closely related and emerged from same primary branch. Three functional motifs were predicted in eleven species while only two were found in L. orbonalis, S. exigua and T. absoluta. AChE in eleven species followed secretory pathway and have signal peptides. No signal peptides were predicted for S. exigua, L. orbonalis and T. absoluta and follow non secretory pathway. Arginine methylation and cysteine palmotylation was found in all species except S. exigua, L. orbonalis and T. absoluta. Glycosylphosphatidylinositol (GPI) anchor was predicted in only nine species.

Monoamine Oxidase Inhibitors: A Review of Their Anti-Inflammatory Therapeutic Potential and Mechanisms of Action

Chronic inflammatory diseases are debilitating, affect patients' quality of life, and are a significant financial burden on health care. Inflammation is regulated by pro-inflammatory cytokines and chemokines that are expressed by immune and non-immune cells, and their expression is highly controlled, both spatially and temporally. Their dysregulation is a hallmark of chronic inflammatory and autoimmune diseases. Significant evidence supports that monoamine oxidase (MAO) inhibitor drugs have anti-inflammatory effects. MAO inhibitors are principally prescribed for the management of a variety of central nervous system (CNS)-associated diseases such as depression, Alzheimer's, and Parkinson's; however, they also have anti-inflammatory effects in the CNS and a variety of non-CNS tissues. To bolster support for their development as anti-inflammatories, it is critical to elucidate their mechanism(s) of action. MAO inhibitors decrease the generation of end products such as hydrogen peroxide, aldehyde, and ammonium. They also inhibit biogenic amine degradation, and this increases cellular and pericellular catecholamines in a variety of immune and some non-immune cells. This decrease in end product metabolites and increase in catecholamines can play a significant role in the anti-inflammatory effects of MAO inhibitors. This review examines MAO inhibitor effects on inflammation in a variety of in vitro and in vivo CNS and non-CNS disease models, as well as their anti-inflammatory mechanism(s) of action.

Uveitis: Molecular Pathogenesis and Emerging Therapies

The profound impact that vision loss has on human activities and quality of life necessitates understanding the etiology of potentially blinding diseases and their clinical management. The unique anatomic features of the eye and its sequestration from peripheral immune system also provides a framework for studying other diseases in immune privileged sites and validating basic immunological principles. Thus, early studies of intraocular inflammatory diseases (uveitis) were at the forefront of research on organ transplantation. These studies laid the groundwork for foundational discoveries on how immune system distinguishes self from non-self and established current concepts of acquired immune tolerance and autoimmunity. Our charge in this review is to examine how advances in molecular cell biology and immunology over the past 3 decades have contributed to the understanding of mechanisms that underlie immunopathogenesis of uveitis. Particular emphasis is on how advances in biotechnology have been leveraged in developing biologics and cell-based immunotherapies for uveitis and other neuroinflammatory diseases.

Local and distant responses to single pulse electrical stimulation reflect different forms of connectivity

Measuring connectivity in the human brain involves innumerable approaches using both noninvasive (fMRI, EEG) and invasive (intracranial EEG or iEEG) recording modalities, including the use of external probing stimuli, such as direct electrical stimulation. To examine how different measures of connectivity correlate with one another, we compared 'passive' measures of connectivity during resting state conditions to the more 'active' probing measures of connectivity with single pulse electrical stimulation (SPES). We measured the network engagement and spread of the cortico-cortico evoked potential (CCEP) induced by SPES at 53 out of 104 total sites across the brain, including cortical and subcortical regions, in patients with intractable epilepsy (N=11) who were undergoing intracranial recordings as a part of their clinical care for identifying seizure onset zones. We compared the CCEP network to functional, effective, and structural measures of connectivity during a resting state in each patient. Functional and effective connectivity measures included correlation or Granger causality measures applied to stereoEEG (sEEGs) recordings. Structural connectivity was derived from diffusion tensor imaging (DTI) acquired before intracranial electrode implant and monitoring (N=8). The CCEP network was most similar to the resting state voltage correlation network in channels near to the stimulation location. In contrast, the distant CCEP network was most similar to the DTI network. Other connectivity measures were not as similar to the CCEP network. These results demonstrate that different connectivity measures, including those derived from active stimulation-based probing, measure different, complementary aspects of regional interrelationships in the brain.

Analysis and Reduction of Nonlinear Distortion in AC-Coupled CMOS Neural Amplifiers with Tunable Cutoff Frequencies

Integrated CMOS neural amplifiers are key elements of modern large-scale neuroelectronic interfaces. The neural amplifiers are routinely AC-coupled to electrodes to remove the DC voltage. The large resistances required for the AC coupling circuit are usually realized using MOSFETs that are nonlinear. Specifically, designs with tunable cutoff frequency of the input high‑pass filter may suffer from excessive nonlinearity, since the gate-source voltages of the transistors forming the pseudoresistors vary following the signal being amplified. Consequently, the nonlinear distortion in such circuits may be high for signal frequencies close to the cutoff frequency of the input filter. Here we propose a simple modification of the architecture of a tunable AC-coupled amplifier, in which the bias voltages V_gs of the transistors forming the pseudoresistor are kept constant independently of the signal levels, what results in significantly improved linearity. Based on numerical simulations of the proposed circuit designed in 180 nm technology we analyze the Total Harmonic Distortion levels as a function of signal frequency and amplitude. We also investigate the impact of basic amplifier parameters—gain, cutoff frequency of the AC coupling circuit, and silicon area—on the distortion and noise performance. The post-layout simulations of the complete test ASIC show that the distortion is very significantly reduced at frequencies near the cutoff frequency, when compared to the commonly used circuits. The THD values are below 1.17% for signal frequencies 1 Hz–10 kHz and signal amplitudes up to 10 mV peak-to-peak. The preamplifier area is only 0.0046 mm² and the noise is 8.3 µV_rms in the 1 Hz–10 kHz range. To our knowledge this is the first report on a CMOS neural amplifier with systematic characterization of THD across complete range of frequencies and amplitudes of neuronal signals recorded by extracellular electrodes.

Neuropathic corneal pain and dry eye: a continuum of nociception

Throughout the body, damage to peripheral nerves normally involved in nociception may produce a constellation of symptoms-including irritation, itchiness and pain. The neurobiological processes involved in corneal symptoms of dry eye (DE) and neuropathic corneal pain (NCP) have not been clearly considered in terms of nociceptive processing. The conventional underlying presumption is that a labelled line principle is responsible; that these distinct perceptions are hard coded by primary afferent inputs to the central nervous system. This presumption oversimplifies the neurobiological mechanisms underlying somatosensory perception. The labelled line perspective that DE represents a chronic pain condition does not make intuitive sense: how can an eye condition that is not painful in most cases be considered a pain condition? Does not chronic pain by definition require pain to be present? On the other hand, NCP, a term that clearly denotes a painful condition, has historically seemed to resonate with clinical significance. Both DE and NCP can share similar features, yet their differentiation is not always clear. As is often the case, clinical terms arise from different disciplines, with DE evolving from ophthalmological findings and NCP inspired by pain neurophysiology. This review evaluates the current definition of these terms, the rationale for their overlap and how the neurophysiology of itch impacts our understanding of these conditions as a continuum of the same disease. Despite the complexity of nociceptive physiology, an understanding of these mechanisms will allow us a more precise therapeutic approach.

Adverse maternal environment and western diet impairs cognitive function and alters hippocampal glucocorticoid receptor promoter methylation in male mice

Adverse maternal environment (AME) and high‐fat diet in early childhood increase the risk of cognitive impairment and depression later in life. Cognitive impairment associates with hippocampal dysfunction. A key regulator of hippocampal function is the glucocorticoid receptor. Increased hippocampal GR expression associates with cognitive impairment and depression. Transcriptional control of GR relies in part upon the DNA methylation status at multiple alternative initiation sites that are tissue specific, with exon 1.7 being hippocampal specific. Increased exon 1.7 expression associates with upregulated hippocampal GR expression in early life stress animal models. However, the effects of AME combined with postweaning western diet (WD) on offspring behaviors and the expression of GR exon 1 variants in the hippocampus are unknown. We hypothesized that AME and postweaning WD would impair cognitive function and cause depression‐like behavior in offspring in conjunction with dysregulated hippocampal expression of total GR and exon 1.7 variant in mice. We found that AME‐WD impaired learning and memory in male adult offspring concurrently with increased hippocampal expression of total GR and GR 1.7. We also found that increased GR 1.7 expression was associated with decreased DNA methylation at the GR 1.7 promoter. We speculate that decreased DNA methylation at the GR 1.7 promoter plays a role in AME‐WD induced increase of GR in the hippocampus. This increased GR expression may subsequently contribute to hippocampus dysfunction and lead to the cognitive impairment seen in this model.

MRCKβ links Dasm1 to actin rearrangements to promote dendrite development

Proper dendrite morphogenesis and synapse formation are essential for neuronal development and function. Dasm1, a member of the immunoglobulin superfamily, is known to promote dendrite outgrowth and excitatory synapse maturation in vitro. However, the in vivo function of Dasm1 in neuronal development and the underlying mechanisms are not well understood. To learn more, Dasm1 knockout mice were constructed and employed to confirm that Dasm1 regulates dendrite arborization and spine formation in vivo. We performed a yeast two-hybrid screen using Dasm1, revealing MRCKβ as a putative partner; additional lines of evidence confirmed this interaction and identified cytoplasmic proline-rich region (823–947 aa) of Dasm1 and MRCKβ self-activated kinase domain (CC1, 410–744 aa) as necessary and sufficient for binding. Using co-immunoprecipitation assay, autophosphorylation assay, and BS3 cross-linking assay, we show that Dasm1 binding triggers a change in MRCKβ’s conformation and subsequent dimerization, resulting in autophosphorylation and activation. Activated MRCKβ in turn phosphorylates a class 2 regulatory myosin light chain, which leads to enhanced actin rearrangement, causing the dendrite outgrowth and spine formation observed before. Removal of Dasm1 in mice leads to behavioral abnormalities. Together, these results reveal a crucial molecular pathway mediating cell surface and intracellular signaling communication to regulate actin dynamics and neuronal development in the mammalian brain.

Kcns3 deficiency disrupts Parvalbumin neuron physiology in mouse prefrontal cortex: Implications for the pathophysiology of schizophrenia

The unique fast spiking (FS) phenotype of cortical parvalbumin-positive (PV) neurons depends on the expression of multiple subtypes of voltage-gated potassium channels (Kv). PV neurons selectively express Kcns3, the gene encoding Kv9.3 subunits, suggesting that Kcns3 expression is critical for the FS phenotype. KCNS3 expression is lower in PV neurons in the neocortex of subjects with schizophrenia, but the effects of this alteration are unclear, because Kv9.3 subunit function is poorly understood. Therefore, to assess the role of Kv9.3 subunits in PV neuron function, we combined gene expression analyses, computational modeling, and electrophysiology in acute slices from the cortex of Kcns3-deficient mice. Kcns3 mRNA levels were ~ 50% lower in cortical PV neurons from Kcns3-deficient relative to wildtype mice. While silent per se, Kv9.3 subunits are believed to amplify the Kv2.1 current in Kv2.1-Kv9.3 channel complexes. Hence, to assess the consequences of reducing Kv9.3 levels, we simulated the effects of decreasing the Kv2.1-mediated current in a computational model. The FS cell model with reduced Kv2.1 produced spike trains with irregular inter-spike intervals, or stuttering, and greater Na⁺ channel inactivation. As in the computational model, PV basket cells (PVBCs) from Kcns3-deficient mice displayed spike trains with strong stuttering, which depressed PVBC firing. Moreover, Kcns3 deficiency impaired the recruitment of PVBC firing at gamma frequency by stimuli mimicking synaptic input observed during cortical UP states. Our data indicate that Kv9.3 subunits are critical for PVBC physiology and suggest that KCNS3 deficiency in schizophrenia could impair PV neuron firing, possibly contributing to deficits in cortical gamma oscillations in the illness.

Curcuma Longa, the "Golden Spice" to Counteract Neuroinflammaging and Cognitive Decline-What Have We Learned and What Needs to Be Done

Due to the global increase in lifespan, the proportion of people showing cognitive impairment is expected to grow exponentially. As target-specific drugs capable of tackling dementia are lagging behind, the focus of preclinical and clinical research has recently shifted towards natural products. Curcumin, one of the best investigated botanical constituents in the biomedical literature, has been receiving increased interest due to its unique molecular structure, which targets inflammatory and antioxidant pathways. These pathways have been shown to be critical for neurodegenerative disorders such as Alzheimer’s disease and more in general for cognitive decline. Despite the substantial preclinical literature on the potential biomedical effects of curcumin, its relatively low bioavailability, poor water solubility and rapid metabolism/excretion have hampered clinical trials, resulting in mixed and inconclusive findings. In this review, we highlight current knowledge on the potential effects of this natural compound on cognition. Furthermore, we focus on new strategies to overcome current limitations in its use and improve its efficacy, with attention also on gender-driven differences.

Brain multigraph prediction using topology-aware adversarial graph neural network

Brain graphs (i.e, connectomes) constructed from medical scans such as magnetic resonance imaging (MRI) have become increasingly important tools to characterize the abnormal changes in the human brain. Due to the high acquisition cost and processing time of multimodal MRI, existing deep learning frameworks based on Generative Adversarial Network (GAN) focused on predicting the missing multimodal medical images from a few existing modalities. While brain graphs help better understand how a particular disorder can change the connectional facets of the brain, synthesizing a target brain multigraph (i.e, multiple brain graphs) from a single source brain graph is strikingly lacking. Additionally, existing graph generation works mainly learn one model for each target domain which limits their scalability in jointly predicting multiple target domains. Besides, while they consider the global topological scale of a graph (i.e., graph connectivity structure), they overlook the local topology at the node scale (e.g., how central a node is in the graph). To address these limitations, we introduce topology-aware graph GAN architecture (topoGAN), which jointly predicts multiple brain graphs from a single brain graph while preserving the topological structure of each target graph. Its three key innovations are: (i) designing a novel graph adversarial auto-encoder for predicting multiple brain graphs from a single one, (ii) clustering the encoded source graphs in order to handle the mode collapse issue of GAN and proposing a cluster-specific decoder, (iii) introducing a topological loss to force the prediction of topologically sound target brain graphs. The experimental results using five target domains demonstrated the outperformance of our method in brain multigraph prediction from a single graph in comparison with baseline approaches.

Immunoceptive inference: why are psychiatric disorders and immune responses intertwined?

There is a steadily growing literature on the role of the immune system in psychiatric disorders. So far, these advances have largely taken the form of correlations between specific aspects of inflammation (e.g. blood plasma levels of inflammatory markers, genetic mutations in immune pathways, viral or bacterial infection) with the development of neuropsychiatric conditions such as autism, bipolar disorder, schizophrenia and depression. A fundamental question remains open: why are psychiatric disorders and immune responses intertwined? To address this would require a step back from a historical mind-body dualism that has created such a dichotomy. We propose three contributions of active inference when addressing this question: translation, unification, and simulation. To illustrate these contributions, we consider the following questions. Is there an immunological analogue of sensory attenuation? Is there a common generative model that the brain and immune system jointly optimise? Can the immune response and psychiatric illness both be explained in terms of self-organising systems responding to threatening stimuli in their external environment, whether those stimuli happen to be pathogens, predators, or people? Does false inference at an immunological level alter the message passing at a psychological level (or vice versa) through a principled exchange between the two systems?

Cortical and subcortical hemodynamic changes during sleep slow waves in human light sleep

EEG slow waves, the hallmarks of NREM sleep are thought to be crucial for the regulation of several important processes, including learning, sensory disconnection and the removal of brain metabolic wastes. Animal research indicates that slow waves may involve complex interactions within and between cortical and subcortical structures. Conventional EEG in humans, however, has a low spatial resolution and is unable to accurately describe changes in the activity of subcortical and deep cortical structures. To overcome these limitations, here we took advantage of simultaneous EEG-fMRI recordings to map cortical and subcortical hemodynamic (BOLD) fluctuations time-locked to slow waves of light sleep. Recordings were performed in twenty healthy adults during an afternoon nap. Slow waves were associated with BOLD-signal increases in the posterior brainstem and in portions of thalamus and cerebellum characterized by preferential functional connectivity with limbic and somatomotor areas, respectively. At the cortical level, significant BOLD-signal decreases were instead found in several areas, including insula and somatomotor cortex. Specifically, a slow signal increase preceded slow-wave onset and was followed by a delayed, stronger signal decrease. Similar hemodynamic changes were found to occur at different delays across most cortical brain areas, mirroring the propagation of electrophysiological slow waves, from centro-frontal to inferior temporo-occipital cortices. Finally, we found that the amplitude of electrophysiological slow waves was positively related to the magnitude and inversely related to the delay of cortical and subcortical BOLD-signal changes. These regional patterns of brain activity are consistent with theoretical accounts of the functions of sleep slow waves.

The multisensory cocktail party problem in adults: Perceptual segregation of talking faces on the basis of audiovisual temporal synchrony

Social interactions often involve a cluttered multisensory scene consisting of multiple talking faces. We investigated whether audiovisual temporal synchrony can facilitate perceptual segregation of talking faces. Participants either saw four identical or four different talking faces producing temporally jittered versions of the same visible speech utterance and heard the audible version of the same speech utterance. The audible utterance was either synchronized with the visible utterance produced by one of the talking faces or not synchronized with any of them. Eye tracking indicated that participants exhibited a marked preference for the synchronized talking face, that they gazed more at the mouth than the eyes overall, that they gazed more at the eyes of an audiovisually synchronized than a desynchronized talking face, and that they gazed more at the mouth when all talking faces were audiovisually desynchronized. These findings demonstrate that audiovisual temporal synchrony plays a major role in perceptual segregation of multisensory clutter and that adults rely on differential scanning strategies of a talker's eyes and mouth to discover sources of multisensory coherence.

A genome-wide microRNA screen identifies the microRNA-183/96/182 cluster as a modulator of circadian rhythms

The regulatory mechanisms of circadian rhythms have been studied primarily at the level of the transcription-translation feedback loops of protein-coding genes. Regulatory modules involving noncoding RNAs are less thoroughly understood. In particular, emerging evidence has revealed the important role of microRNAs (miRNAs) in maintaining the robustness of the circadian system. To identify miRNAs that have the potential to modulate circadian rhythms, we conducted a genome-wide miRNA screen using U2OS luciferase reporter cells. Among 989 miRNAs in the library, 120 changed the period length in a dose-dependent manner. We further validated the circadian regulatory function of an miRNA cluster, miR-183/96/182, both in vitro and in vivo. We found that all three members of this miRNA cluster can modulate circadian rhythms. Particularly, miR-96 directly targeted a core circadian clock gene, PER2. The knockout of the miR-183/96/182 cluster in mice showed tissue-specific effects on circadian parameters and altered circadian rhythms at the behavioral level. This study identified a large number of miRNAs, including the miR-183/96/182 cluster, as circadian modulators. We provide a resource for further understanding the role of miRNAs in the circadian network and highlight the importance of miRNAs as a genome-wide layer of circadian clock regulation.

Circadian Rhythm Disorders and Corresponding Functional Brain Abnormalities in Young Female Nurses: A Preliminary Study

Objective: Shift work is associated with a decrease in melatonin level and perturbation of the circadian rhythm; however, it is unknown if these lead to functional brain changes. In this study, we investigated whether circadian rhythm disorders caused by shift work are related to changes in brain functional connectivity (FC) and regional homogeneity (ReHo) using whole-brain resting-state functional magnetic resonance imaging (fMRI).

Methods: This prospective case-control study included nine female night shift nurses and nine age-matched female day work nurses with normal sleep rhythms. To assess sleep quality and mood, participants were asked to complete questionnaires. Serum melatonin and cortisol levels were measured. ReHo of whole-brain resting-state function and seed-based FC of the bilateral hypothalamus were compared between groups. Variables that differed significantly between groups were used to examine the association between questionnaire scores and hormone levels and fMRI data.

Results: The night shift nurses had significantly lower sleep quality and melatonin levels; lower ReHo activation in the bilateral cerebellar hemisphere and higher ReHo in the bilateral occipital lobe and left parietal lobe; and higher FC from the hypothalamus to the right cingulate gyrus, right putamen, and vermis than did the day shift nurses. Activation of the right cerebellar hemisphere left superior parietal gyrus, and the right superior occipital gyrus was correlated with sleep quality scores. Moreover, activation of the right cerebellar hemisphere (r = 0.583, P = 0.011) was correlated with melatonin levels, and higher sleepiness scores were associated with stronger FC between the hypothalamus and vermis (r = 0.501, P = 0.034).

Conclusions: Circadian rhythm disorder caused by night shift work can lead to a decrease in sleep quality and melatonin level, as well as a series of changes in brain FC and ReHo.

Discovery of HN37 as a Potent and Chemically Stable Antiepileptic Drug Candidate

We previously reported that P-retigabine (P-RTG), a retigabine (RTG) analogue bearing a propargyl group at the nitrogen atom in the linker of RTG, displayed moderate anticonvulsant efficacy. Recently, our further efforts led to the discovery of HN37 (pynegabine), which demonstrated satisfactory chemical stability upon deleting the ortho liable -NH₂ group and installing two adjacent methyl groups to the carbamate motif. HN37 exhibited enhanced activation potency toward neuronal Kv7 channels and high in vivo efficacy in a range of pre-clinical seizure models, including the maximal electroshock test and a 6 Hz model of pharmacoresistant limbic seizures. With its improved chemical stability, strong efficacy, and better safety margin, HN37 has progressed to clinical trial in China for epilepsy treatment.

Hiding in Plain Sight: Formation and Function of Stress Granules During Microbial Infection of Mammalian Cells

Stress granule (SG) formation is a host cell response to stress-induced translational repression. SGs assemble with RNA-binding proteins and translationally silent mRNA. SGs have been demonstrated to be both inhibitory to viruses, as well as being subverted for viral roles. In contrast, the function of SGs during non-viral microbial infections remains largely unexplored. A handful of microbial infections have been shown to result in host SG assembly. Nevertheless, a large body of evidence suggests SG formation in hosts is a widespread response to microbial infection. Diverse stresses caused by microbes and their products can activate the integrated stress response in order to inhibit translation initiation through phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α). This translational response in other contexts results in SG assembly, suggesting that SG assembly can be a general phenomenon during microbial infection. This review explores evidence for host SG formation in response to bacterial, fungal, and protozoan infection and potential functions of SGs in the host and for adaptations of the pathogen.

Synaptic Zinc: An Emerging Player in Parkinson's Disease

Alterations of zinc homeostasis have long been implicated in Parkinson's disease (PD). Zinc plays a complex role as both deficiency and excess of intracellular zinc levels have been incriminated in the pathophysiology of the disease. Besides its role in multiple cellular functions, Zn²⁺ also acts as a synaptic transmitter in the brain. In the forebrain, subset of glutamatergic neurons, namely cortical neurons projecting to the striatum, use Zn²⁺ as a messenger alongside glutamate. Overactivation of the cortico-striatal glutamatergic system is a key feature contributing to the development of PD symptoms and dopaminergic neurotoxicity. Here, we will cover recent evidence implicating synaptic Zn²⁺ in the pathophysiology of PD and discuss its potential mechanisms of actions. Emphasis will be placed on the functional interaction between Zn²⁺ and glutamatergic NMDA receptors, the most extensively studied synaptic target of Zn²⁺.

The Evolution of Social Dominance through Reinforcement Learning

AbstractGroups of social animals are often organized into dominance hierarchies that are formed through pairwise interactions. There is much experimental data on hierarchies, examining such things as winner, loser, and bystander effects, as well as the linearity and replicability of hierarchies, but there is a lack evolutionary analyses of these basic observations. Here I present a game theory model of hierarchy formation in which individuals adjust their aggressive behavior toward other group members through reinforcement learning. Individual traits such as the tendency to generalize learning between interactions with different individuals, the rate of learning, and the initial tendency to be aggressive are genetically determined and can be tuned by evolution. I find that evolution favors individuals with high social competence, making use of individual recognition, bystander observational learning, and, to a limited extent, generalizing learned behavior between opponents when adjusting their behavior toward other group members. The results are in qualitative agreement with experimental data, for instance, in finding weaker winner effects compared to loser effects.

Study on the Safety of Human Oligodendrocyte Precursor Cell Transplantation in Young Animals and Its Efficacy on Myelination

Oligodendrocyte precursor cells (OPCs) can differentiate into myelinating oligodendrocytes during embryonic development, thereby representing an important potential source for myelin repair or regeneration. To the best of our knowledge, there are very few OPCs from human sources (human-derived OPCs [hOPCs]). In this study, we aimed to evaluate the safety and remyelination capacity of hOPCs developed in our laboratory, transplanted into the lateral ventricles of young animals. Several acute and chronic toxicity experiments were conducted in which different doses of hOPCs were transplanted into the lateral ventricles of Sprague–Dawley rats of different ages. The toxicity, biodistribution, and tumor formation ability of the injected hOPCs were examined by evaluating the rats' vital signs, developmental indicators, neural reflexes, as well as by hematology, immunology, and pathology. In addition, the hOPCs were transplanted into the corpus callosum of the shiverer mouse to verify cell myelination efficacy. Overall, our results show that transplanted hOPCs into young mice are nontoxic to their organ function or immune system. The transplanted cells engrafted in the brain and did not appear in other organs, nor did they cause tissue proliferation or tumor formation. In terms of efficacy, the transplanted hOPCs were able to form myelin in the corpus callosum, alleviate the trembling phenotype of shiverer mice, and promote normal development. The transplantation of hOPCs is safe; they can effectively form myelin in the brain, thereby providing a theoretical basis for the future clinical transplantation of hOPCs.

Rewired Pathways and Disrupted Pathway Crosstalk in Schizophrenia Transcriptomes by Multiple Differential Coexpression Methods

Transcriptomic studies of mental disorders using the human brain tissues have been limited, and gene expression signatures in schizophrenia (SCZ) remain elusive. In this study, we applied three differential co-expression methods to analyze five transcriptomic datasets (three RNA-Seq and two microarray datasets) derived from SCZ and matched normal postmortem brain samples. We aimed to uncover biological pathways where internal correlation structure was rewired or inter-coordination was disrupted in SCZ. In total, we identified 60 rewired pathways, many of which were related to neurotransmitter, synapse, immune, and cell adhesion. We found the hub genes, which were on the center of rewired pathways, were highly mutually consistent among the five datasets. The combinatory list of 92 hub genes was generally multi-functional, suggesting their complex and dynamic roles in SCZ pathophysiology. In our constructed pathway crosstalk network, we found “Clostridium neurotoxicity” and “signaling events mediated by focal adhesion kinase” had the highest interactions. We further identified disconnected gene links underlying the disrupted pathway crosstalk. Among them, four gene pairs (PAK1:SYT1, PAK1:RFC5, DCTN1:STX1A, and GRIA1:MAP2K4) were normally correlated in universal contexts. In summary, we systematically identified rewired pathways, disrupted pathway crosstalk circuits, and critical genes and gene links in schizophrenia transcriptomes.

Delivering Clinically on Our Knowledge of Oxytocin and Sensory Stimulation: The Potential of Infant Carrying in Primary Prevention

Oxytocin (OT) is one of the most intensively researched neuropeptides during the three past decades. In benign social contexts, OT exerts a range of desirable socioemotional, stress-reducing, and immunoregulatory effects in mammals and humans and influences mammalian parenting. Consequentially, research in potential pharmacological applications of OT toward human social deficits/disorders and physical illness has increased substantially. Regrettably, the results from the administration of exogenous OT are still relatively inconclusive. Research in rodent maternal developmental programming has demonstrated the susceptibility of offspring endogenous OT systems to maternal somatosensory stimulation, with consequences for behavioral, epigenetic, cognitive, and neurological outcomes. A translation of this animal research into practically feasible human parenting recommendations has yet to happen, despite the significant prevention potential implied by the maternal developmental programming research. Extended physical contact with full-term healthy infants in the months following birth (infant carrying) might constitute the human equivalent of those specific rodent maternal behaviors, found to positively influence emerging OT systems. Findings from both OT and maternal programming research parallel those found for infants exposed to such extended parental physical contact, whether through skin-to-skin contact or infant carrying. Clinical support of parents to engage in extended physical contact represents a feasible intervention to create optimum conditions for the development of infant OT systems, with potential beneficial long-term health effects.

Novel Tools and Investigative Approaches for the Study of Oligodendrocyte Precursor Cells (NG2-Glia) in CNS Development and Disease

Oligodendrocyte progenitor cells (OPCs), also referred to as NG2-glia, are the most proliferative cell type in the adult central nervous system. While the primary role of OPCs is to serve as progenitors for oligodendrocytes, in recent years, it has become increasingly clear that OPCs fulfil a number of other functions. Indeed, independent of their role as stem cells, it is evident that OPCs can regulate the metabolic environment, directly interact with and modulate neuronal function, maintain the blood brain barrier (BBB) and regulate inflammation. In this review article, we discuss the state-of-the-art tools and investigative approaches being used to characterize the biology and function of OPCs. From functional genetic investigation to single cell sequencing and from lineage tracing to functional imaging, we discuss the important discoveries uncovered by these techniques, such as functional and spatial OPC heterogeneity, novel OPC marker genes, the interaction of OPCs with other cells types, and how OPCs integrate and respond to signals from neighboring cells. Finally, we review the use of in vitro assay to assess OPC functions. These methodologies promise to lead to ever greater understanding of this enigmatic cell type, which in turn will shed light on the pathogenesis and potential treatment strategies for a number of diseases, such as multiple sclerosis (MS) and gliomas.

Vitamin B-6-Induced Neuropathy: Exploring the Mechanisms of Pyridoxine Toxicity

Vitamin B-6 in the form of pyridoxine (PN) is commonly used by the general population. The use of PN-containing supplements has gained lots of attention over the past years as they have been related to the development of peripheral neuropathy. In light of this, the number of reported cases of adverse health effects due to the use of vitamin B-6 have increased. Despite a long history of study, the pathogenic mechanisms associated with PN toxicity remain elusive. Therefore, the present review is focused on investigating the mechanistic link between PN supplementation and sensory peripheral neuropathy. Excessive PN intake induces neuropathy through the preferential injury of sensory neurons. Recent reports on hereditary neuropathy due to pyridoxal kinase (PDXK) mutations may provide some insight into the mechanism, as genetic deficiencies in PDXK lead to the development of axonal sensory neuropathy. High circulating concentrations of PN may lead to a similar condition via the inhibition of PDXK. The mechanism behind PDXK-induced neuropathy is unknown; however, there is reason to believe that it may be related to γ-aminobutyric acid (GABA) neurotransmission. Compounds that inhibit PDXK lead to convulsions and reductions in GABA biosynthesis. The absence of central nervous system-related symptoms in PDXK deficiency could be due to differences in the regulation of PDXK, where PDXK activity is preserved in the brain but not in peripheral tissues. As PN is relatively impermeable to the blood-brain barrier, PDXK inhibition would similarly be confined to the peripheries and, as a result, GABA signaling may be perturbed within peripheral tissues, such as sensory neurons. Perturbed GABA signaling within sensory neurons may lead to excitotoxicity, neurodegeneration, and ultimately, the development of peripheral neuropathy. For several reasons, we conclude that PDXK inhibition and consequently disrupted GABA neurotransmission is the most plausible mechanism of toxicity.

Subcortical regions of the human visual system do not process faces holistically

Face perception is considered to be evolutionarily adaptive and conserved across species. While subcortical visual brain areas are implicated in face perception based on existing evidence from phylogenetic and ontogenetic studies, whether these subcortical structures contribute to more complex visual computations such as the holistic processing (HP) of faces in humans is unknown. To address this issue, we used a well-established marker of HP, the composite face effect (CFE), with a group of adult human observers, and presented two sequential faces in a trial monocularly or interocularly using a Wheatstone stereoscope. HP refers to the finding that two identical top (or bottom) halves of a face are judged to be different when their task-irrelevant bottom (or top) halves belong to different faces. Because humans process faces holistically, they are unable to ignore the information from the irrelevant half of the composite face, and this is true to an even greater extent when the two halves of the faces are aligned compared with when they are misaligned ('Alignment effect'). The results revealed the HP effect and also uncovered the Alignment effect, a key marker of the CFE. The findings also indicated a monocular advantage, replicating the known subcortical contribution to face perception. There was, however, no statistically significant difference in the CFE when the images were presented in the monocular versus interocular conditions. These findings indicate that HP is not necessarily mediated by the subcortical visual pathway, and suggest that further investigation of cortical, rather than subcortical, structures might advance our understanding of HP and its role in face processing.

Impact of parent-child separation on children's social-emotional development: a cross-sectional study of left-behind children in poor rural areas of China

BACKGROUND

Parent-child separation is a considerable adversity for left-behind children (LBC), but there is little evidence on the association between detailed characteristics of parent-child separation and social-emotional development among LBC. This study examined the characteristics of parent-child separation and its impacts on developmental delay among under-3 LBC in poor rural China.

METHODS

We used data from 811 LBC surveyed in five poor counties in rural China in 2018. Detailed characteristics of their parental migration were recalled by their primary caregivers in face-to-face interviews. The children's social-emotional development was measured by using the Ages and Stages Questionnaire: Social-Emotional. Logistic regression was employed to examine the association of detailed characteristics of parent-child separation with early social-emotional problems after adjusting for the children's and primary caregivers' sociodemographic characteristics.

RESULTS

287 (35.4%) children were left behind by fathers and cared for by mothers (FM-MC), while 524 (64.6%) were left behind by both parents and cared for by grandparents (PM-GC). The rate of social-emotional problems among LBC was 36.8% (PM-GC vs FM-MC: 40.6% vs 29.5%; aOR 1.51, 95% CI: 1.06 to 2.16). For paternal migration, the medians of the child's age at the first migration and average duration per migration were 3 months (IQR: 1 to 9 months) and 4.48 months (IQR: 2.38 to 7.54 months), respectively. For maternal migration, the corresponding values were 9 months (IQR: 6 to 13 months) and 4.65 months (IQR: 2.71 to 7.62 months), respectively. On average, LBC had been separated from fathers for 72% of their life due to paternal migration and from mothers for 52% of their life due to maternal migration. No significant association was found between the detailed characteristics of paternal migration and social-emotional development among LBC, while social-emotional problems among LBC were significantly associated with the proportion of cumulative duration of maternal migration in the child's lifetime (aOR 2.83; 95% CI: 1.13 to 7.10).

CONCLUSIONS

LBC under 3 years had a high risk of social-emotional problems in poor rural China. Cumulative exposure to maternal migration may be detrimental to LBC's early social-emotional development. Programs are necessary to support these children as well as their families.

Childhood socioeconomic status is associated with psychometric intelligence and microstructural brain development

Childhood socioeconomic status is robustly associated with various children's cognitive factors and neural mechanisms. Here we show the association of childhood socioeconomic status with psychometric intelligence and mean diffusivity and fractional anisotropy using diffusion tensor imaging at the baseline experiment (N = 285) and longitudinal changes in these metrics after 3.0 ± 0.3 years (N = 223) in a large sample of normal Japanese children (mean age = 11.2 ± 3.1 years). After correcting for confounding factors, cross-sectional and longitudinal analyses show that higher childhood socioeconomic status is associated with greater baseline and baseline to follow-up increase of psychometric intelligence and mean diffusivity in areas around the bilateral fusiform gyrus. These results demonstrate that higher socioeconomic status is associated with higher psychometric intelligence measures and altered microstructural properties in the fusiform gyrus which plays a key role in reading and letter recognition and further augmentation of such tendencies during development. Definitive conclusions regarding the causality of these relationships requires intervention and physiological studies. However, the current findings should be considered when developing and revising policies regarding education.

ZIGIR, a Granule-Specific Zn2+ Indicator, Reveals Human Islet α Cell Heterogeneity

Numerous mammalian cells contain abundant Zn²⁺ in their secretory granules, yet available Zn²⁺ sensors lack the desired specificity and sensitivity for imaging granular Zn²⁺. We developed a fluorescent zinc granule indicator, ZIGIR, that possesses numerous desired properties for live cell imaging, including >100-fold fluorescence enhancement, membrane permeability, and selective enrichment to acidic granules. The combined advantages endow ZIGIR with superior sensitivity and specificity for imaging granular Zn²⁺. ZIGIR enables separation of heterogenous β cells based on their insulin content and sorting of mouse islets into pure α cells and β cells. In human islets, ZIGIR facilitates sorting of endocrine cells into highly enriched α cells and β cells, reveals unexpectedly high Zn²⁺ activity in the somatostatin granule of some δ cells, and uncovers variation in the glucagon content among human α cells. We expect broad applications of ZIGIR for studying Zn²⁺ biology and Zn²⁺-rich secretory granules and for engineering β cells with high insulin content for treating diabetes.

Functional Brain Connectivity Patterns Associated with Visual Hallucinations in Dementia with Lewy Bodies

BACKGROUND

The presence of recurrent, complex visual hallucinations (VH) is among the core clinical features of dementia with Lewy bodies (DLB). It has been proposed that VH arise from a disrupted organization of functional brain networks. However, studies are still limited, especially investigating the resting-state functional brain features underpinning VH in patients with dementia.

OBJECTIVE

The aim of the present pilot study was to investigate whether there were any alterations in functional connectivity associated with VH in DLB.

METHODS

Seed-based analyses and independent component analysis (ICA) of resting-state fMRI scans were carried out to explore differences in functional connectivity between DLB patients with and without VH.

RESULTS

Seed-based analyses reported decreased connectivity of the lateral geniculate nucleus, the superior parietal lobule and the putamen with the medial frontal gyrus in DLB patients with VH. Visual areas showed a pattern of both decreased and increased functional connectivity. ICA revealed between-group differences in the default mode network (DMN).

CONCLUSION

Functional connectivity analyses suggest dysfunctional top-down and bottom-up processes and DMN-related alterations in DLB patients with VH. This impairment might foster the generation of false visual images that are misinterpreted, ultimately resulting in VH.

Sevoflurane impairs m6A-mediated mRNA translation and leads to fine motor and cognitive deficits

Clinical surgical practices have found that children who undergo multiple anesthesia may have an increased risk of deficiencies in cognition and fine motor control. Here, we report that YT521-B homology domain family 1 (YTHDF1), a critical reader protein for N6-methyladenosine-modified mRNA, was significantly downregulated in the prefrontal cortex of young mice after multiple sevoflurane anesthesia exposures. Importantly, sevoflurane led to a decrease in protein synthesis in mouse cortical neurons that was fully rescued by YTHDF1, suggesting that anesthesia may affect early brain development by affecting m6A-dependent mRNA translation. Transcriptome-wide experiments showed that numerous mRNA targets related to synaptic functions in the prefrontal mouse cortex were associated with m6A methylation and YTHDF1. In particular, we found that synaptophysin, a critical presynaptic protein, was specifically modified by m6A methylation and associated with YTHDF1, and m6A methylation of synaptophysin decreased with multiple sevoflurane exposures. Importantly, we showed that fine motor control skills and cognitive functions were impaired in mice with multiple anesthesia exposures, and these effects were fully reversed by reintroducing YTHDF1 through a blood-brain barrier (BBB)-crossing viral delivery system. Finally, we found that the fine motor skills in children who underwent prolonged anesthesia were compromised 6 months after surgery. Our findings indicated that impairment in the translational regulation of mRNA via N6-methyladenosine methylation is a potential mechanism underlying the effects of anesthesia on neural development in the young brain. 1. N6-methyladenosine (m6A) modifications were involved in anesthesia-induced neurotoxicity. 2. Sevoflurane impairs m6A-mediated mRNA translation and leads to fine motor deficits in young mice. 3. YTHDF1, a m6A reader protein, rescued sevoflurane-induced protein synthesis inhibition and fine motor deficits in young mice.

The Role of Iconic Gestures in Speech Comprehension: An Overview of Various Methodologies

Iconic gesture-speech integration is a relatively recent field of investigation with numerous researchers studying its various aspects. The results obtained are just as diverse. The definition of iconic gestures is often overlooked in the interpretations of results. Furthermore, while most behavioral studies have demonstrated an advantage of bimodal presentation, brain activity studies show a diversity of results regarding the brain regions involved in the processing of this integration. Clinical studies also yield mixed results, some suggesting parallel processing channels, others a unique and integrated channel. This review aims to draw attention to the methodological variations in research on iconic gesture-speech integration and how they impact conclusions regarding the underlying phenomena. It will also attempt to draw together the findings from other relevant research and suggest potential areas for further investigation in order to better understand processes at play during speech integration process.

In vivo Morphometry of Inner Plexiform Layer (IPL) Stratification in the Human Retina With Visible Light Optical Coherence Tomography

From the bipolar cells to higher brain visual centers, signals in the vertebrate visual system are transmitted along parallel on and off pathways. These two pathways are spatially segregated along the depth axis of the retina. Yet, to our knowledge, there is no way to directly assess this anatomical stratification in vivo. Here, employing ultrahigh resolution visible light Optical Coherence Tomography (OCT) imaging in humans, we report a stereotyped reflectivity pattern of the inner plexiform layer (IPL) that parallels IPL stratification. We characterize the topography of this reflectivity pattern non-invasively in a cohort of normal, young adult human subjects. This proposed correlate of IPL stratification is accessible through non-invasive ocular imaging in living humans. Topographic variations should be carefully considered when designing studies in development or diseases of the visual system.

The development of Need-Threat Internal Resiliency Theory in COVID-19 crisis utilizing deductive axiomatic approach

Resiliency for older people represents the capacity to return to equilibrium when difficulties arise and was found as integral predictor of their health status. This study aims to develop a theory that attempts to explain the older adults' resiliency perspectives during crisis and how it has affected their well-being and quality of life as population group. Deductive theory generation using axiomatic approach was adopted resulting to five axioms that served as basis for the generation of three propositions such as: (1) An older person's health needs have tendencies to develop into a health threat, (2) when the threat is perceived, older persons developed a sense of internal control and adaptation to the changes it creates known as internal resiliency, and (3) internal resiliency can influence the quality of life in old age. The evolved theory suggests that in times of crisis (e.g., COVID-19 pandemic), health needs develop into a health threat that compels older persons to develop internal resiliency in order to preserve their integrity, wellbeing and quality of life. This study widens the nursing perspectives in addressing older persons' resiliency by the unique condition at which older clients are placed affecting both the pathological nature of the illness as well as the preventive interventions which the society is forced to implement.

Regulation of Cardiac Conduction and Arrhythmias by Ankyrin/Spectrin-Based Macromolecular Complexes

The cardiac conduction system is an extended network of excitable tissue tasked with generation and propagation of electrical impulses to signal coordinated contraction of the heart. The fidelity of this system depends on the proper spatio-temporal regulation of ion channels in myocytes throughout the conduction system. Importantly, inherited or acquired defects in a wide class of ion channels has been linked to dysfunction at various stages of the conduction system resulting in life-threatening cardiac arrhythmia. There is growing appreciation of the role that adapter and cytoskeletal proteins play in organizing ion channel macromolecular complexes critical for proper function of the cardiac conduction system. In particular, members of the ankyrin and spectrin families have emerged as important nodes for normal expression and regulation of ion channels in myocytes throughout the conduction system. Human variants impacting ankyrin/spectrin function give rise to a broad constellation of cardiac arrhythmias. Furthermore, chronic neurohumoral and biomechanical stress promotes ankyrin/spectrin loss of function that likely contributes to conduction disturbances in the setting of acquired cardiac disease. Collectively, this review seeks to bring attention to the significance of these cytoskeletal players and emphasize the potential therapeutic role they represent in a myriad of cardiac disease states.

Elovl5 Expression in the Central Nervous System of the Adult Mouse

ELOVL5 (Elongase of Very-Long Fatty Acid 5) gene encodes for an enzyme that elongates long chain fatty acids, with a marked preference for polyunsaturated molecules. In particular, it plays an essential role in the elongation of omega-3 and omega-6 fatty acids, precursors for long-chain polyunsaturated fatty acids (PUFAs). Mutations of ELOVL5 cause the spino-cerebellar ataxia type 38 (SCA38), a rare autosomal neurological disease characterized by gait abnormality, dysarthria, dysphagia, hyposmia and peripheral neuropathy, conditions well represented by a mouse model with a targeted deletion of this gene (Elovl5^–/– mice). However, the expression pattern of this enzyme in neuronal and glial cells of the central nervous system (CNS) is still uninvestigated. This work is aimed at filling this gap of knowledge by taking advantage of an Elovl5-reporter mouse line and immunofluorescence analyses on adult mouse CNS sections and glial cell primary cultures. Notably, Elovl5 appears expressed in a region- and cell type-specific manner. Abundant Elovl5-positive cells were found in the cerebellum, brainstem, and primary and accessory olfactory regions, where mitral cells show the most prominent expression. Hippocampal pyramidal cells of CA2/CA3 where also moderately labeled, while in the rest of the telencephalon Elovl5 expression was high in regions related to motor control. Analysis of primary glial cell cultures revealed Elovl5 expression in oligodendroglial cells at various maturation steps and in microglia, while astrocytes showed a heterogeneous in vivo expression of Elovl5. The elucidation of Elovl5 CNS distribution provides relevant information to understand the physiological functions of this enzyme and its PUFA products, whose unbalance is known to be involved in many pathological conditions.

Towards physiologically relevant human pluripotent stem cell (hPSC) models of Parkinson's disease

The derivation of human embryonic stem cells followed by the discovery of induced pluripotent stem cells and leaps in genome editing approaches have continuously fueled enthusiasm for the development of new models of neurodegenerative diseases such as Parkinson's disease (PD). PD is characterized by the relative selective loss of dopaminergic neurons (DNs) in specific areas of substantia nigra pars compacta (SNpc). While degeneration in late stages can be widespread, there is stereotypic early degeneration of these uniquely vulnerable neurons. Various causes of selective vulnerability have been investigated but much remains unclear. Most studies have sought to identify cell autonomous properties of the most vulnerable neurons. However, recent findings from genetic studies and model systems have added to our understanding of non-cell autonomous contributions including regional-specific neuro-immune interactions with astrocytes, resident or damage-activated microglia, neuro-glia cell metabolic interactions, involvement of endothelial cells, and damage to the vascular system. All of these contribute to specific vulnerability and, along with aging and environmental factors, might be integrated in a complex stressor-threshold model of neurodegeneration. In this forward-looking review, we synthesize recent advances in the field of PD modeling using human pluripotent stem cells, with an emphasis on organoid and complex co-culture models of the nigrostriatal niche, with emerging CRISPR applications to edit or perturb expression of causal PD genes and associated risk factors, such as GBA, to understand the impact of these genes on relevant phenotypes.

Targeting Mitochondrial Metabolism in Clear Cell Carcinoma of the Ovaries

Ovarian clear cell carcinoma (OCCC) is a rare but chemorefractory tumor. About 50% of all OCCC patients have inactivating mutations of ARID1A, a member of the SWI/SNF chromatin-remodeling complex. Members of the SWI/SNF remodeling have emerged as regulators of the energetic metabolism of mammalian cells; however, the role of ARID1A as a modulator of the mitochondrial metabolism in OCCCs is yet to be defined. Here, we show that ARID1A loss results in increased mitochondrial metabolism and renders ARID1A-mutated cells increasingly and selectively dependent on it. The increase in mitochondrial activity following ARID1A loss is associated with increase in c-Myc expression and increased mitochondrial number and reduction of their size consistent with a higher mitochondrial cristae/outer membrane ratio. Significantly, preclinical testing of the complex I mitochondrial inhibitor IACS-010759 showed it extends overall survival in a preclinical model of ARID1A-mutated OCCC. These findings provide for the targeting mitochondrial activity in ARID1A-mutated OCCCs.

Inducible knockout of Clec16a in mice results in sensory neurodegeneration

CLEC16A has been shown to play a role in autophagy/mitophagy processes. Additionally, genetic variants in CLEC16A have been implicated in multiple autoimmune diseases. We generated an inducible whole-body knockout, Clec16aΔUBC mice, to investigate the loss of function of CLEC16A. The mice exhibited a neuronal phenotype including tremors and impaired gait that rapidly progressed to dystonic postures. Nerve conduction studies and pathological analysis revealed loss of sensory axons that are associated with this phenotype. Activated microglia and astrocytes were found in regions of the CNS. Several mitochondrial-related proteins were up- or down-regulated. Upregulation of interferon stimulated gene 15 (IGS15) were observed in neuronal tissues. CLEC16A expression inversely related to IGS15 expression. ISG15 may be the link between CLEC16A and downstream autoimmune, inflammatory processes. Our results demonstrate that a whole-body, inducible knockout of Clec16a in mice results in an inflammatory neurodegenerative phenotype resembling spinocerebellar ataxia.

The Modulatory Effects of Intermittent Theta Burst Stimulation in Combination With Mirror Hand Motor Training on Functional Connectivity: A Proof-of-Concept Study

Mirror training (MT) is an observation-based motor learning strategy. Intermittent theta burst stimulation (iTBS) is an accelerated form of excitatory repetitive transcranial magnetic stimulation (rTMS) that has been used to enhance the cortical excitability of the motor cortices. This study aims to investigate the combined effects of iTBS with MT on the resting state functional connectivity at alpha frequency band in healthy adults. Eighteen healthy adults were randomized into one of three groups—Group 1: iTBS plus MT, Group 2: iTBS plus sham MT, and Group 3: sham iTBS plus MT. Participants in Groups 1 and 3 observed the mirror illusion of the moving (right) hand in a plain mirror for four consecutive sessions, one session/day, while participants in Group 2 received the same training with a covered mirror. Real or sham iTBS was applied daily over right motor cortex prior to the training. Resting state electroencephalography (EEG) at baseline and post-training was recorded when participants closed their eyes. The mixed-effects model demonstrated a significant interaction effect in the coherence between FC4 and C4 channels, favoring participants in Group 1 over Group 3 (Δβ = −0.84, p = 0.048). A similar effect was also found in the coherence between FC3 and FC4 channels favoring Group 1 over Group 3 (Δβ = −0.43, p = 0.049). In contrast to sham iTBS combined with MT, iTBS combined with MT may strengthen the functional connectivity between bilateral premotor cortices and ipsilaterally within the motor cortex of the stimulated hemisphere. In contrast to sham MT, real MT, when combined with iTBS, might diminish the connectivity among the contralateral parietal–frontal areas.

Identifying Biological Signatures of N-Acetylcysteine for Non-Suicidal Self-Injury in Adolescents and Young Adults

The prevalence of non-suicidal self-injury (NSSI) is high in adolescents and young adults. However, there is a paucity of evidence-based treatments to address this clinical problem. An open-label, pilot study in the target population showed that treatment with oral N-acetylcysteine (NAC), a widely available dietary supplement, was associated with reduction in NSSI frequency. In preparation for a biologically informed design of an efficacy trial, a critical preliminary step is to clarify NAC's biological signatures, or measures of the mechanisms underlying its clinical effects. Toward that end, we propose a 2-stage project to investigate NAC's biological signatures (changes in glutathione (GSH) and/or glutamate (Glu)) in women with NSSI. The first stage; a double-blind randomized placebo-controlled study will focus on identifying the optimal dose to achieve meaningful change in GSH and Glu during short-term (4 weeks) NAC treatment in 36 women aged 16-24 years with NSSI. Go/No-go criteria to determine if the study will progress to the second stage include pre-specified changes in brain and blood measures of GSH. Changes in the brain GSH are measured through magnetic resonance spectroscopy (MRS). The dose for the stage 2 will be selected based on the biological changes and the tolerability observed in the stage 1. The stage 2 will seek to replicate the biological signature findings in an 8-week trial in a new patient cohort, and examine the relationships among biological signatures, NAC pharmacokinetics and clinical response. This 2-stage project is unique as it unifies clinical psychiatric measurements, quantitative MRS and pharmacological approaches in the first placebo-controlled clinical trial of NAC in young women with NSSI.

TRIAL REGISTRATION

The stage 1 trial protocol has been registered on https://clinicaltrials.gov/ with ClinicalTrials.gov ID "NCT04005053" (Registered on 02 July 2019. Available from: https://clinicaltrials.gov/ct2/show/NCT04005053).

Effectiveness and mechanisms of adipose-derived stem cell therapy in animal models of Parkinson's disease: a systematic review and meta-analysis

Animal models provide an opportunity to assess the optimal treatment way and the underlying mechanisms of direct clinical application of adipose-derived stem cells (ADSCs). Previous studies have evaluated the effects of primitive and induced ADSCs in animal models of Parkinson's disease (PD). Here, eight databases were systematically searched for studies on the effects and in vivo changes caused by ADSC intervention. Quality assessment was conducted using a 10-item risk of bias tool. For the subsequent meta-analysis, study characteristics were extracted and effect sizes were computed. Ten out of 2324 published articles (n = 169 animals) were selected for further meta-analysis. After ADSC therapy, the rotation behavior (10 experiments, n = 156 animals) and rotarod performance (3 experiments, n = 54 animals) were improved (P < 0.000 01 and P = 0.000 3, respectively). The rotation behavior test reflected functional recovery, which may be due to the neurogenesis from neuronally differentiated ADSCs, resulting in a higher pooled effect size of standard mean difference (SMD) (- 2.59; 95% CI, - 3.57 to - 1.61) when compared to that of primitive cells (- 2.18; 95% CI, - 3.29 to - 1.07). Stratified analyses by different time intervals indicated that ADSC intervention exhibited a long-term effect. Following the transplantation of ADSCs, tyrosine hydroxylase-positive neurons recovered in the lesion area with pooled SMD of 13.36 [6.85, 19.86]. Transplantation of ADSCs is a therapeutic option that shows long-lasting effects in animal models of PD. The potential mechanisms of ADSCs involve neurogenesis and neuroprotective effects. The standardized induction of neural form of transplanted ADSCs can lead to a future application in clinical practice.

Effects of APOE ε2 on the Fractional Amplitude of Low-Frequency Fluctuation in Mild Cognitive Impairment: A Study Based on the Resting-State Functional MRI

BACKGROUND

Apolipoprotein E (APOE) ε2 is a protective genetic factor for Alzheimer's disease (AD). However, the potential interaction effects between the APOE ε2 allele and disease status on the intrinsic brain activity remain elusive.

METHODS

We identified 73 healthy control (HC) with APOE ε3/ε3, 61 mild cognitive impairment (MCI) subjects with APOE ε3/ε3, 24 HC with APOE ε2/ε3, and 10 MCI subjects with APOE ε2/ε3 from the ADNI database. All subjects underwent a resting-state functional MRI and Fluoro-deoxy-glucose positron emission tomography (FDG-PET). We used a fractional amplitude of low-frequency fluctuation (fALFF) to explore the spontaneous brain activity. Based on the mixed-effects analysis, we explored the interaction effects between the APOE ε2 allele versus disease status on brain activity and metabolism in a voxel-wise fashion (GRF corrected, p < 0.01), followed by post hoc two-sample t-tests (Bonferroni corrected, p < 0.05). We then investigated the relationship between the mean imaging metrics and cognitive abilities.

RESULTS

There are no significant differences in gender, age, or education among the four groups. The interaction effect on brain activity was located in the inferior parietal lobule (IPL). Post hoc analysis showed that APOE ε2/ε3 MCI had an increased IPL fALFF than APOE ε3/ε3 MCI. Regarding the APOE ε2 allele effects, we found that ε2 carriers had a decreased fALFF in the transverse temporal gyrus than non-carriers. Also, FDG-PET results showed a lower SUVR of the frontal lobe in APOE ε2 carriers than non-carriers. Furthermore, fALFF of IPL was correlated with the visuospatial function (r = -0.16, p < 0.05).

CONCLUSION

APOE ε2 carriers might have a better brain reservation when coping with AD-related pathologies.

Social Behavior Is Modulated by Valence-Encoding mPFC-Amygdala Sub-circuitry

The prefrontal cortex and amygdala are anatomical substrates linked to both social information and emotional valence processing, but it is not known whether sub-circuits in the medial prefrontal cortex (mPFC) that project to the basolateral amygdala (BLA) are recruited and functionally contribute to social approach-avoidance behavior. Using retrograde labeling of mPFC projections to the BLA, we find that BLA-projecting neurons in the infralimbic cortex (IL) are preferentially activated in response to a social cue as compared with BLA-projecting neurons in the prelimbic cortex (PL). Chemogenetic interrogation of these sub-circuits shows that activation of PL-BLA or inhibition of IL-BLA circuits impairs social behavior. Sustained closed-loop optogenetic activation of PL-BLA circuitry induces social impairment, corresponding to a negative emotional state as revealed by real-time place preference behavioral avoidance. Reactivation of foot shock-responsive PL-BLA circuitry impairs social behavior. Altogether, these data suggest a circuit-level mechanism by which valence-encoding mPFC-BLA sub-circuits shape social approach-avoidance behavior.

Huang et al. investigate a circuit involving two brain regions important for both social and emotional processing. Activation of descending projections to the basolateral amygdala from the prelimbic cortex abolishes social preference and produces behavioral avoidance. Reactivation of negative stimulus-responsive neurons in this circuit abolishes social preference.

Behavioral tagging as a mechanism for aversive-memory formation under acute stress

The behavioral tagging (BT) hypothesis postulates that a weak learning experience, which only induces short-term memory, may benefit from another event that provides plasticity-related proteins (PRPs) to establish a long-lasting memory. According to BT, the weak experience sets a transient learning tag at specific activated sites, and its temporal and spatial convergence with the PRPs allows the long-term memory (LTM) formation. In this work, rats were subjected to a weak inhibitory avoidance (IAw) training and we observed that acute stress (elevated platform, EP) experienced 1 hr before IAw promoted IA-LTM formation. This effect was dependent on glucocorticoid-receptor activity as well as protein synthesis in the dorsal hippocampus. However, the same stress has negative effects on IA-LTM formation when training is strong, probably by competing for necessary PRPs. Furthermore, our experiments showed that EP immediately after training did not impair the setting of the learning tag and even facilitated IA-LTM formation. These findings reveal different impacts of a given acute stressful experience on the formation of an aversive memory that could be explained by BT processes.

Intentional mind-wandering as intentional omission: the surrealist method

Mind-wandering seems to be paradigmatically unintentional. However, experimental findings have yielded the paradoxical result that mind-wandering can also be intentional. In this paper, we first present the paradox of intentional mind-wandering and then explain intentional mind-wandering as the intentional omission to control one's own thoughts. Finally, we present the surrealist method for artistic production to illustrate how intentional omission of control over thoughts can be deployed towards creative endeavors.