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Alterations in the extracellular matrix (ECM) are common in epilepsy, yet whether they are cause or consequence of disease is unknow. Using Theiler’s virus infection model of acquired epilepsy we findde novoexpression of chondroitin sulfate proteoglycans (CSPGs), a major ECM component, in dentate gyrus (DG) and amygdala exclusively in mice with seizures. Preventing synthesis of CSPGs specifically in DG and amygdala by deletion of major CSPG aggrecan reduced seizure burden. Patch-clamp recordings from dentate granule cells (DGCs) revealed enhanced intrinsic and synaptic excitability in seizing mice that was normalized by aggrecan deletion.In situexperiments suggest that DGCs hyperexcitability results from negatively charged CSPGs increasing stationary cations (K+, Ca2+) on the membrane thereby depolarizing neurons, increasing their intrinsic and synaptic excitability. We show similar changes in CSPGs in pilocarpine-induced epilepsy suggesting enhanced CSPGs in the DG and amygdala may be a common ictogenic factor and novel therapeutic potential.

Objective Previously, we reported that inhibition of the astrocytic cystine/glutamate antiporter system xc- (SXC), using sulfasalazine (SAS), decreased evoked excitatory signaling in three distinct hyperexcitability models ex vivo. The current study expands on this work by evaluating the in vivo efficacy of SAS in decreasing astrogliosis-mediated seizure burden seen in the beta-1 integrin knockout (B1KO) model. Methods Video-EEG (electroencephalography) monitoring (24/7) was obtained using Biopac EEG acquisition hardware and software. EEG spectral analysis was performed using MATLAB. SAS was used at an equivalence of doses taken by Crohn's disease patients. Whole-cell patch-clamp recordings were made from cortical layer 2/3 pyramidal neurons. Results We report that 100% of B1KO mice that underwent 24/7 video-EEG monitoring developed spontaneous recurrent seizures and that intraperitoneal administration of SAS significantly reduced seizure frequency in B1KOs compared to B1KOs receiving sham saline. Spectral analysis found an acute reduction in EEG power following SAS treatment in B1KOs; however, this effect was not observed in nonepileptic control mice receiving SAS. Finally, whole-cell recordings from SXC knockout mice had hyperpolarized neurons and SXC-B1 double knockouts fired significantly less action potentials in response to current injection compared to B1KOs with SXC. Significance To devise effective strategies in finding relief for one-in-three patients with epilepsy who experience drug-resistant epilepsy we must continue to explore the mechanisms regulating glutamate homeostasis. This study explored the efficacy of targeting an astrocytic glutamate antiporter, SXC, as a novel antiepileptic drug (AED) target and further characterized a unique mouse model in which chronic astrogliosis is sufficient to induce spontaneous seizures and epilepsy. These findings may serve as a foundation to further assess the potential for SAS or inform the development of more potent and specific compounds that target SXC as a novel treatment for epilepsy. National Institutes of Health [5R01CA227149, 5R01NS036692] Published version National Institutes of Health, Grant/Award Number: 5R01CA227149 and 5R01NS036692

Supplementary Figure 3 from Inhibition of the Sodium-Potassium-Chloride Cotransporter Isoform-1 Reduces Glioma Invasion

Supplementary Methods, Figure Legends 1-3 from Inhibition of the Sodium-Potassium-Chloride Cotransporter Isoform-1 Reduces Glioma Invasion

Supplementary Figure 1 from Inhibition of the Sodium-Potassium-Chloride Cotransporter Isoform-1 Reduces Glioma Invasion

Supplementary Figure 2 from Inhibition of the Sodium-Potassium-Chloride Cotransporter Isoform-1 Reduces Glioma Invasion

Perineuronal nets (PNNs) are dense, negatively charged extracellular matrices that cover the cell body of fast-spiking inhibitory neurons. Synapses can be embedded and stabilized by PNNs believed to prevent synaptic plasticity. We find that in cortical fast-spiking interneurons synaptic terminals localize to perforations in the PNNs, 95% of which contain either excitatory or inhibitory synapses or both. The majority of terminals also colocalize with astrocytic processes expressing Kir4.1 as well as glutamate (Glu) and GABA transporters, hence can be considered tripartite synapses. In the adult brain, degradation of PNNs does not alter axonal terminals but causes expansion of astrocytic coverage of the neuronal somata. However, loss of PNNs impairs astrocytic transmitter and K+ uptake and causes spillage of synaptic Glu into the extrasynaptic space. This data suggests a hitherto unrecognized role of PNNs, to synergize with astrocytes to contain synaptically released signals.

Small-scale robots capable of remote active steering and navigation offer great potential for biomedical applications. However, the current design and manufacturing procedure impede their miniaturization and integration of various diagnostic and therapeutic functionalities. Here, we present a robotic fiber platform for integrating navigation, sensing, and therapeutic functions at a submillimeter scale. These fiber robots consist of ferromagnetic, electrical, optical, and microfluidic components, fabricated with a thermal drawing process. Under magnetic actuation, they can navigate through complex and constrained environments, such as artificial vessels and brain phantoms. Moreover, we utilize Langendorff mouse hearts model, glioblastoma microplatforms, and in vivo mouse models to demonstrate the capabilities of sensing electrophysiology signals and performing localized treatment. Additionally, we demonstrate that the fiber robots can serve as endoscopes with embedded waveguides. These fiber robots provide a versatile platform for targeted multimodal detection and treatment at hard-to-reach locations in a minimally invasive and remotely controllable manner.

Epilepsy is one of the most common chronic brain diseases and is often associated with cognitive, behavioral, or other medical conditions. The need for therapies that would prevent, ameliorate, or cure epilepsy and the attendant comorbidities is a priority for both epilepsy research and public health. In 2018, the National Institute of Neurological Disease and Stroke (NINDS) convened a workshop titled “Accelerating the Development of Therapies for Antiepileptogenesis and Disease Modification” that brought together preclinical and clinical investigators and industry and regulatory bodies’ representatives to discuss and propose a roadmap to accelerate the development of antiepileptogenic (AEG) and disease‐modifying (DM) new therapies. This report provides a summary of the discussions and proposals of the Preclinical Science working group. Highlights of the progress of collaborative preclinical research projects on AEG/DM of ongoing research initiatives aiming to improve infrastructure and translation to clinical trials are presented. Opportunities and challenges of preclinical epilepsy research, vis‐à‐vis clinical research, were extensively discussed, as they pertain to modeling of specific epilepsy types across etiologies and ages, the utilization of preclinical models in AG/DM studies, and the strategies and study designs, as well as on matters pertaining to transparency, data sharing, and reporting research findings. A set of suggestions on research initiatives, infrastructure, workshops, advocacy, and opportunities for expanding the borders of epilepsy research were discussed and proposed as useful initiatives that could help create a roadmap to accelerate and optimize preclinical translational AEG/DM epilepsy research.

Background: Vascular pericytes stabilize blood vessels and contribute to their maturation, while playing other key roles in microvascular function. Nevertheless, relatively little is known about involvement of their precursors in the earliest stages of vascular development, specifically during vasculogenesis. Methods: We combined high-power, time-lapse imaging with transcriptional profiling of emerging pericytes and endothelial cells in reporter mouse and cell lines. We also analyzed conditional transgenic animals deficient in Cx43/Gja1 (connexin 43/gap junction alpha-1) expression within Ng2+ cells. Results: A subset of Ng2-DsRed+ cells, likely pericyte/mural cell precursors, arose alongside endothelial cell differentiation and organization and physically engaged vasculogenic endothelium in vivo and in vitro. We found no overlap between this population of differentiating pericyte/mural progenitors and other lineages including hemangiogenic and neuronal/glial cell types. We also observed cell-cell coupling and identified Cx43-based gap junctions contributing to pericyte–endothelial cell precursor communication during vascular assembly. Genetic loss of Cx43/Gja1 in Ng2+ pericyte progenitors compromised embryonic blood vessel formation in a subset of animals, while surviving mutants displayed little-to-no vessel abnormalities, suggesting a resilience to Cx43/Gja1 loss in Ng2+ cells or potential compensation by additional connexin isoforms. Conclusions: Together, our data suggest that a distinct pericyte lineage emerges alongside vasculogenesis and directly communicates with the nascent endothelium via Cx43 during early vessel formation. Cx43/Gja1 loss in pericyte/mural cell progenitors can induce embryonic vessel dysmorphogenesis, but alternate connexin isoforms may be able to compensate. These data provide insight that may reshape the current framework of vascular development and may also inform tissue revascularization/vascularization strategies.

Simple Summary Glioblastoma multiforme (GBM) is a highly invasive brain tumor that typically has poor patient outcomes. This is due in part to aggressive tumor expansion within the brain parenchyma. This process is aided by assiduous glutamate release via the System xc- (SXC) cystine–glutamate antiporter. SXC is over-expressed in roughly half of GBM tumors where it is responsible for glutamate-mediated neuronal cell death and provides excess glutamate to fuel tumor-associated epilepsy. Available pharmacological inhibitors have some promise, although they lack specificity and have poor bioavailability. Therefore, identifying regulators of SXC may provide a superior avenue to target GBM. In this study, we identify tumor protein 53 (TP53) as a molecular regulator of SXC in GBM. Abstract Glioblastoma multiforme (GBM) is a deadly brain tumor with a large unmet therapeutic need. Here, we tested the hypothesis that wild-type p53 is a negative transcriptional regulator of SLC7A11, the gene encoding the System xc- (SXC) catalytic subunit, xCT, in GBM. We demonstrate that xCT expression is inversely correlated with p53 expression in patient tissue. Using representative patient derived (PDX) tumor xenolines with wild-type, null, and mutant p53 we show that p53 expression negatively correlates with xCT expression. Using chromatin immunoprecipitation studies, we present a molecular interaction whereby p53 binds to the SLC7A11 promoter, suppressing gene expression in PDX GBM cells. Accordingly, genetic knockdown of p53 increases SLC7A11 transcript levels; conversely, over-expressing p53 in p53-null GBM cells downregulates xCT expression and glutamate release. Proof of principal studies in mice with flank gliomas demonstrate that daily treatment with the mutant p53 reactivator, PRIMA-1Met, results in reduced tumor growth associated with reduced xCT expression. These findings suggest that p53 is a molecular switch for GBM glutamate biology, with potential therapeutic utility.

Glioblastoma (GBM) is the most common primary malignant brain tumor with a dismal median survival of 15 months. Calcium signaling regulates a plethora of cellular processes making it an ideal target for therapeutic intervention. T-type calcium channels (TTCCs) are low voltage gated calcium channels expressed in various types of neurons throughout the brain regulating glutamatergic synaptic transmission. Our group identified T-type calcium channels as upregulated in GBM cells, stem cells and human tumors. Utilizing an FDA repurposed TTCC blocker mibefradil we demonstrated that inhibition of TTCCs decreases GBM malignancy parameters. To further elucidate the mechanisms of action of TTCC, we treated glioma stem cells (GSCs) with mibefradil followed by RNA-sequencing. Analysis of the transcriptome revealed that mibefradil downregulated genes associated with neuronal processes including synapse organization, postsynaptic density and glutamatergic synapses. The effects of TTCC inhibition on neuronal processes led us to examine the role of neuronal TTCC in promoting GBM growth. Genetic loss of TTCC, Cav3.2 via knockout (KO) in the microenvironment of mice xenografted with syngeneic cell lines exhibited delayed tumor progression. Cav3.2 KO mice exhibited a 5.5-fold reduction in tumor volume as measured by MRI and an increase in survival compared to WT mice. Cav3.2 KO tumors exhibited a decrease in proliferation measured by Ki67+ cells compared to WT mice. Cav3.2KO tumors exhibit fewer connections between tumor cells and neurons as measured by immunofluorescence. To further test the roles of neuronal Cav3.2 in GBM, we isolated WT and Cav3.2KO neurons for neuron-GBM co-cultures. Cav3.2KO neuron-GBM co-cultures exhibited a significant decrease in proliferation compared to WT neuron-GBM co-cultures. Additionally, Cav3.2KO neuron-GBM co-cultures exhibited a decrease in synaptic connections and a decrease in neuronal projections to GBM cells compared to WT neuron-GBM co-cultures. These data uncover a new role for TTCC Cav3.2 in promoting neuron-GBM interactions and GBM growth.

Rapid and widespread testing of severe acute respiratory coronavirus 2 (SARS-CoV-2) is essential for an effective public health response aimed at containing and mitigating the coronavirus disease 2019 (COVID-19) pandemic. Successful health policy implementation relies on early identification of infected individuals and extensive contact tracing. However, rural communities, where resources for testing are sparse or simply absent, face distinctive challenges to achieving this success. Accordingly, we report the development of an academic, public land grant University laboratory-based detection assay for the identification of SARS-CoV-2 in samples from various clinical specimens that can be readily deployed in areas where access to testing is limited. The test, which is a quantitative reverse transcription polymerase chain reaction (RT-qPCR)-based procedure, was validated on samples provided by the state laboratory and submitted for FDA Emergency Use Authorization. Our test exhibits comparable sensitivity and exceeds specificity and inclusivity values compared to other molecular assays. Additionally, this test can be re-configured to meet supply chain shortages, modified for scale up demands, and is amenable to several clinical specimens. Test development also involved 3D engineering critical supplies and formulating a stable collection media that allowed samples to be transported for hours over a dispersed rural region without the need for a cold-chain. These two elements that were critical when shortages impacted testing and when personnel needed to reach areas that were geographically isolated from the testing center. Overall, using a robust, easy-to-adapt methodology, we show that an academic laboratory can supplement COVID-19 testing needs and help local health departments assess and manage outbreaks. This additional testing capacity is particularly germane for smaller cities and rural regions that would otherwise be unable to meet the testing demand., Here, the authors report the development of a versatile academic, SARSCoV-2 RT-qPCR molecular diagnostic test that uses 3D printed technology for sample collection, is implemented in rural setting in the US state of Virginia and validated in its population.

Tumor protein 53 (p53) regulates fundamental pathways of cellular growth and differentiation. Aberrant p53 expression in glioblastoma multiforme, a terminal brain cancer, has been associated with worse patient outcomes and decreased chemosensitivity. Therefore, correctly identifying p53 status in glioblastoma is of great clinical significance. p53 immunohistochemistry is used to detect pathological presence of the TP53 gene product. Here, we examined the relationship between p53 immunoreactivity and TP53 mutation status by DNA Sanger sequencing in adult glioblastoma. Of 41 histologically confirmed samples, 27 (66%) were immunopositive for a p53 mutation via immunohistochemistry. Utilizing gene sequencing, we identified only eight samples (20%) with TP53 functional mutations and one sample with a silent mutation. Therefore, a ≥10% p53 immunohistochemistry threshold for predicting TP53 functional mutation status in glioma is insufficient. Implementing this ≥10% threshold, we demonstrated a remarkably low positive-predictive value (30%). Furthermore, the sensitivity and specificity with ≥10% p53 immunohistochemistry to predict TP53 functional mutation status were 100% and 42%, respectively. Our data suggests that unless reliable sequencing methodology is available for confirming TP53 status, raising the immunoreactivity threshold would increase positive and negative predictive values as well as the specificity without changing the sensitivity of the immunohistochemistry assay.

Astrocytes extend endfeet that enwrap the vasculature. Disruptions to this association in disease coincide with breaches in blood-brain barrier (BBB) integrity, so we asked if the focal ablation of an astrocyte is sufficient to disrupt the BBB. 2Phatal ablation of astrocytes induced a plasticity response whereby surrounding astrocytes extended processes to cover vascular vacancies. This occurred prior to endfoot retraction in young mice yet occurred with significant delay in aged animals. Laser-stimulating replacement astrocytes showed them to induce constrictions in pre-capillary arterioles indicating that replacement astrocytes are functional. Inhibition of EGFR and pSTAT3 significantly reduced astrocyte replacement post-ablation yet without perturbations to BBB integrity. Identical endfoot replacement following astrocyte cell death due to reperfusion post-stroke supports the conclusion that astrocyte plasticity ensures continual vascular coverage so as to retain the BBB. Together, these studies uncover the ability of astrocytes to maintain cerebrovascular coverage via substitution from nearby cells and may represent a novel therapeutic target for vessel recovery post-stroke.

Astrocytes extend endfeet that enwrap the vasculature, and disruptions to this association which may occur in disease coincide with breaches in blood-brain barrier (BBB) integrity. Here we investigate if focal ablation of astrocytes is sufficient to disrupt the BBB in mice. Targeted two-photon chemical apoptotic ablation of astrocytes induced a plasticity response whereby surrounding astrocytes extended processes to cover vascular vacancies. In young animals, replacement processes occur in advance of endfoot retraction, but this is delayed in aged animals. Stimulation of replacement astrocytes results in constriction of pre-capillary arterioles, suggesting that replacement astrocytes are functional. Pharmacological inhibition of pSTAT3, as well as astrocyte specific deletion of pSTAT3, reduces astrocyte replacement post-ablation, without perturbations to BBB integrity. Similar endfoot replacement occurs following astrocyte cell death due to reperfusion in a stroke model. Together, these studies uncover the ability of astrocytes to maintain cerebrovascular coverage via substitution from nearby cells.

Once strictly the domain of medical and graduate education, neuroscience has made its way into the undergraduate curriculum with over 230 colleges and universities now offering a bachelor’s degree in neuroscience. The disciplinary focus on the brain teaches students to apply science to the understanding of human behavior, human interactions, sensation, emotions, and decision making. In this article, we encourage new and existing undergraduate neuroscience programs to envision neuroscience as a broad discipline with the potential to develop competencies suitable for a variety of careers that reach well beyond research and medicine. This article describes our philosophy and illustrates a broad-based undergraduate degree in neuroscience implemented at a major state university, Virginia Tech. We highlight the fact that the research-centered Experimental Neuroscience major is least popular of our four distinct majors, which underscores our philosophy that undergraduate neuroscience can cater to a different audience than traditionally thought.

Given the important functions that glutamate serves in excitatory neurotransmission, understanding the regulation of glutamate in physiological and pathological states is critical to devising novel therapies to treat epilepsy. Exclusive expression of pyruvate carboxylase and glutamine synthetase in astrocytes positions astrocytes as essential regulators of glutamate in the central nervous system (CNS). Additionally, astrocytes can significantly alter the volume of the extracellular space (ECS) in the CNS due to their expression of the bi-directional water channel, aquaporin-4, which are enriched at perivascular endfeet. Rapid ECS shrinkage has been observed following epileptiform activity and can inherently concentrate ions and neurotransmitters including glutamate. This review highlights our emerging knowledge on the various potential contributions of astrocytes to epilepsy, particularly supporting the notion that astrocytes may be involved in seizure initiation via failure of homeostatic responses that lead to increased ambient glutamate. We also review the mechanisms whereby ambient glutamate can influence neuronal excitability, including via generation of the glutamate receptor subunit GluN2B-mediated slow inward currents, as well as indirectly affect neuronal excitability via actions on metabotropic glutamate receptors that can potentiate GluN2B currents and influence neuronal glutamate release probabilities. Additionally, we discuss evidence for upregulation of System xc-, a cystine/glutamate antiporter expressed on astrocytes, in epileptic tissue and changes in expression patterns of glutamate receptors. NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [1R01CA227149-01A1, 1R01NS036692-01A1]; DODUnited States Department of Defense [W81XWH-18-1-0521] This work was supported by NIH grants 1R01CA227149-01A1 and 1R01NS036692-01A1, and DOD grant W81XWH-18-1-0521.

Metallic nano-optoelectrode arrays can simultaneously serve as nanoelectrodes to increase the electrochemical surface-to-volume ratio for high-performance electrical recording and optical nanoantennas to achieve nanoscale light concentrations for ultrasensitive optical sensing. However, it remains a challenge to integrate nano-optoelectrodes with a miniaturized multifunctional probing system for combined electrical recording and optical biosensing in vivo. Here, we report that flexible nano-optoelectrode-integrated multifunctional fiber probes can have hybrid optical-electrical sensing multimodalities, including optical refractive index sensing, surface-enhanced Raman spectroscopy, and electrophysiological recording. By physical vapor deposition of thin metal films through free-standing masks of nanohole arrays, we exploit a scalable nanofabrication process to create nano-optoelectrode arrays on the tips of flexible multifunctional fiber probes. We envision that the development of flexible nano-optoelectrode-integrated multifunctional fiber probes can open significant opportunities by allowing for multimodal monitoring of brain activities with combined capabilities for simultaneous electrical neural recording and optical biochemical sensing at the single-cell level.

One important objective of neuroscience research is to identify disease-specific genes and their proteins, namely, receptors, ion channels, or signaling molecules, whose dysfunction contributes to disease. If we expect that changing their function would alter disease, such disease-specific proteins are often called drug targets. Finding chemicals that can selectively bind to these target proteins and alter their function in a beneficial way then becomes necessary. New or existing drugs are identified serendipitously or by meticulously screening large chemical libraries to isolate a suitable drug candidate. Candidate drugs are then evaluated for their safety, efficacy, and activity in laboratory animals. If successful, these drugs are tested in a limited sample of volunteer human participants, a process called clinical trials. These trials are divided into defined steps; phase I–III trials examine safety, efficacy, and superiority compared with existing drugs, respectively. If possible, drugs are compared with an inert chemical called a placebo, with both patients and investigators blinded to which treatment is received. This process is time-consuming and costly, and unfortunately only 1 of every 10,000 candidate drugs investigated ultimately produces a drug for medical use. In the future drugs may be tailored more specifically to a patient's genetic attributes through an approach referred to as personalized medicine.

Reactive astrocytes are astrocytes undergoing morphological, molecular, and functional remodeling in response to injury, disease, or infection of the CNS. Although this remodeling was first described over a century ago, uncertainties and controversies remain regarding the contribution of reactive astrocytes to CNS diseases, repair, and aging. It is also unclear whether fixed categories of reactive astrocytes exist and, if so, how to identify them. We point out the shortcomings of binary divisions of reactive astrocytes into good-vs-bad, neurotoxic-vs-neuroprotective or A1-vs-A2. We advocate, instead, that research on reactive astrocytes include assessment of multiple molecular and functional parameters—preferably in vivo—plus multivariate statistics and determination of impact on pathological hallmarks in relevant models. These guidelines may spur the discovery of astrocyte-based biomarkers as well as astrocyte-targeting therapies that abrogate detrimental actions of reactive astrocytes, potentiate their neuro- and glioprotective actions, and restore or augment their homeostatic, modulatory, and defensive functions., Funding: CNRS, CEA, ANR, and France Alzheimer to CE.; MCINN (PID2019-107633RB-I00) and Generalitat de Catalunya (2017-SGR547, Grup de demències Sant Pau) to E.G. US Centers for Disease Control and Prevention to J. P.O. Alzheimer’s Association (AACF-17-524184) and NIH-NIA (K08AG064039) to A.S.-P. DFG (SPP1757, STE 552/5, STE 552/4), EU (H2020-MSCA-ITN project 722053 EU-GliaPhD) and BMBF (16GW0182 CONNEXIN) to C.S. Swiss National Science Foundation grant 31003A 173124/1; SNSF NCCR ‘Transcure’ (51NF40-160620); Synapsis Foundation Heidi Seiler-Stiftung 2018-PI01 to A.Volterra. NIH-NINDS (NS084030), Dr. Miriam and Sheldon G. Adelson Medical Foundation and Wings for Life to M.V.S. The authors thank T. Yohannan of Alpha Language Services, Barcelona, for expert copy editing.

Vascular pericytes (PCs) stabilize blood vessels and contribute to their maturation, while also playing key roles in microvascular function. Nevertheless, relatively little is known about their involvement in the earliest stages of vascular development, specifically during vasculogenesis. We combined high-power, time-lapse imaging with transcriptional profiling of PCs and endothelial cells (ECs) in reporter mouse and cell lines. PCs emerged alongside EC differentiation, and physically engaged the vasculogenic endothelium in vivo and in vitro. We observed PC-EC coupling and identified Connexin43 (Cx43)-based gap junctions as key elements in PC-EC communication during vessel assembly. We found no overlap between differentiating PCs and other lineages including hemangiogenic and neuronal/glial cell types. Together, our data suggest that a distinct PC lineage emerges prior to vasculogenesis and participates in early vessel formation through direct communication with nascent endothelium via Cx43 – providing insight that reshapes the current framework of vascular development and informs tissue vascularization strategies.

In spite of their heterogeneous disease presentations, there seems to be a number of recurring themes and proposed disease mechanisms that are shared between many diseases of the nervous system. For example, most neurological disorders present with neuronal cell death, inflammation, glial scarring, and vascular abnormalities, and many also show abnormal protein aggregates. Although only a few diseases are explained by a single genetic mutation, many have multiple genetic risk factors, which together create disease susceptibility that only manifests under certain environmental conditions. Familial forms of disease often highlight the importance of genetic mutations, although these typically affect only a small number of patients. The vast majority, instead, suffer from sporadic disease that may be phenotypically identical, but the underlying genetic changes remain obscure. Neuronal health frequently relies on a common brain-derived neurotropin, and neuronal death most often occurs through glutamate excitotoxicity. Enhanced vulnerability to neuronal death is frequently explained by the high-energy requirement of neurons, making mitochondrial health a linchpin for disease. Finally, there is an increasing recognition that diseases of the nervous system not only affect neurons, but more commonly present as non-cell autonomous, involving many of the surrounding brain support cells as well.

Epilepsy is one of the most common neurological syndromes and affects over 50 million people worldwide. It is characterized by the spontaneous recurrence of seizures, abnormal synchronous discharges of neuronal networks, which present with a range of behavioral abnormalities. The underlying causes vary and are frequently unknown. Seizure risks include congenital brain abnormalities, tumors, trauma, infections, vascular disease, and drug exposure. While epilepsy is pharmacologically curable in two-thirds of patients, the remaining patients suffer lifelong and often severe disabilities and poor quality of life. Advances in basic and clinical science have provided invaluable insights into possible causes of epilepsy, including mutations in ion channels and neurotransmitter receptors. These studies put forth the hypothesis that enhanced susceptibility to seizure is the result of changes in the normal balance between neuronal excitability and inhibition. Various animal models allow the genesis of epilepsy to be studied and the efficacy of new drugs to be tested. The apparent multigenetic nature of the disease suggests that patient-specific “personalized” treatment approaches may be considered in the future.

Glioblastoma multiforme (GBM) is a highly invasive, central nervous system (CNS) cancer for which there is no a cure. Invading tumor cells evade treatment, limiting the efficacy of the current standard of care regimen. Understanding the underlying invasive behaviors that support tumor growth may allow for generation of novel GBM therapies. Zebrafish (Danio rerio) are attractive for genetics and live imaging, and have in recent years, emerged as a model system suitable for cancer biology research. While other groups have studied CNS tumors using zebrafish, few have concentrated on the invasive behaviors supporting the development of these diseases. Previous studies demonstrated that one of the main mechanisms of GBM invasion is perivascular invasion, i.e. single tumor cell migration along blood vessels. Here, we characterize phenotypes, methodology, and potential therapeutic avenues for utilizing zebrafish to model perivascular GBM invasion. Using patient derived xenolines or an adherent cell line, we demonstrate tumor expansion within the zebrafish brain. Within 24 hours post-intracranial injection, D54-MG-tdTomato glioma cells produce finger-like projections along the zebrafish brain vasculature. As few as 25 GBM cells were sufficient to promote single cell vessel co-option. Of note, these tumor-vessel interactions are CNS specific, and do not occur on pre-existing blood vessels when injected into the animal’s peripheral tissue. Tumor-vessel interactions increase over time and can be pharmacologically disrupted through inhibition of Wnt signaling. Therefore, zebrafish serve as a favorable model system to study perivascular glioma invasion, one of the deadly characteristics that make GBM so difficult to treat.

Understanding the cytoarchitecture and wiring of the brain requires improved methods to record and stimulate large groups of neurons with cellular specificity. This requires miniaturized neural interfaces that integrate into brain tissue without altering its properties. Existing neural interface technologies have been shown to provide high-resolution electrophysiological recording with high signal-to-noise ratio. However, with single implantation, the physical properties of these devices limit their access to one, small brain region. To overcome this limitation, we developed a platform that provides three-dimensional coverage of brain tissue through multisite multifunctional fiber-based neural probes guided in a helical scaffold. Chronic recordings from the spatially expandable fiber probes demonstrate the ability of these fiber probes capturing brain activities with a single-unit resolution for long observation times. Furthermore, using Thy1-ChR2-YFP mice we demonstrate the application of our probes in simultaneous recording and optical/chemical modulation of brain activities across distant regions. Similarly, varying electrographic brain activities from different brain regions were detected by our customizable probes in a mouse model of epilepsy, suggesting the potential of using these probes for the investigation of brain disorders such as epilepsy. Ultimately, this technique enables three-dimensional manipulation and mapping of brain activities across distant regions in the deep brain with minimal tissue damage, which can bring new insights for deciphering complex brain functions and dynamics in the near future., Existing neural interfaces are limited in accessing one, small brain region. Here, the authors introduce a scaffold with helix hollow channels, which direct multisite multifunctional fibre probes into the brain at different angles, allowing for simultaneous recording and stimulation across distant regions.

SummaryPericytes (PCs), cells that extend along capillaries to contribute stability and other critical functions to established vasculature, are attracting attention from various fields involving vascular-related pathologies. Here, we demonstrate primary evidence of PC communication with endothelial cells (ECs) prior to tube coalescence. Observations of apparent PCs during early embryogenesis urged development of a mouse embryonic stem cell line (DR-ESCs), enabling unique dual-reporter investigations into earliest PC-EC interactions. Live imaging of differentiating DR-ESCs corroborated emergence of a PC lineage, which preceded EC differentiation, and further revealed highly dynamic PC-EC interactions during coordinated vessel formation. We show direct PC-EC communication via cell microinjection and dye-transfer, and RNA-seq analysis indicates a PC-EC coupling mechanism via gap junction Connexin43 (Cx43), exclusively up-regulated throughout DR-ESC differentiation. High resolution imaging of embryonic and postnatal mouse vasculature substantiates Cx43 plaques at PC-EC borders. These findings indicate a new role for PCs during vasculogenesis via Cx43-mediated communication with ECs.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Microelectrodes provide a direct pathway to investigate brain activities electrically from the external world, which has advanced our fundamental understanding of brain functions and has been utilized for rehabilitative applications as brain-machine interfaces. However, minimizing the tissue response and prolonging the functional durations of these devices remain challenging. Therefore, the development of next-generation microelectrodes as neural interfaces is actively progressing from traditional inorganic materials toward biocompatible and functional organic materials with a miniature footprint, good flexibility, and reasonable robustness. In this study, we developed a miniaturized all polymer-based neural probe with carbon nanofiber (CNF) composites as recording electrodes via the scalable thermal drawing process. We demonstrated that in situ CNF unidirectional alignment can be achieved during the thermal drawing, which contributes to a drastic improvement of electrical conductivity by 2 orders of magnitude compared to a conventional polymer electrode, while still maintaining the mechanical compliance with brain tissues. The resulting neural probe has a miniature footprint, including a recording site with a reduced size comparable to a single neuron and maintained impedance that was able to capture neural activities. Its stable functionality as a chronic implant has been demonstrated with the long-term reliable electrophysiological recording with single-spike resolution and the minimal tissue response over the extended period of implantation in wild-type mice. Technology developed here can be applied to basic chronic electrophysiological studies as well as clinical implementation for neuro-rehabilitative applications.

Objective: Currently prescribed antiepileptic drugs (AEDs) are ineffective in treating approximately 30% of epilepsy patients. Sulfasalazine (SAS) is an US Food and Drug Administration (FDA)–approved drug for the treatment of Crohn disease that has been shown to inhibit the cystine/glutamate antiporter system xc‐ (SXC) and decrease tumor‐associated seizures. This study evaluates the effect of SAS on distinct pharmacologically induced network excitability and determines whether it can further decrease hyperexcitability when administered with currently prescribed AEDs. Methods: Using in vitro cortical mouse brain slices, whole‐cell patch‐clamp recordings were made from layer 2/3 pyramidal neurons. Epileptiform activity was induced with bicuculline (bic), 4‐aminopyridine (4‐AP) and magnesium‐free (Mg2+‐free) solution to determine the effect of SAS on epileptiform events. In addition, voltagesensitive dye (VSD) recordings were performed to characterize the effect of SAS on the spatiotemporal spread of hyperexcitable network activity and compared to currently prescribed AEDs. Results: SAS decreased evoked excitatory postsynaptic currents (eEPSCs) and increased the decay kinetics of evoked inhibitory postsynaptic currents (eIPSCs) in layer 2/3 pyramidal neurons. Although application of SAS to bic and Mg2+‐free–induced epileptiform activity caused a decrease in the duration of epileptiform events, SAS completely blocked 4‐AP–induced epileptiform events. In VSD recordings, SAS decreased VSD optical signals induced by 4‐AP. Co‐application of SAS with the AED topiramate (TPM) caused a significantly further decrease in the spatiotemporal spread of VSD optical signals. Significance: Taken together this study provides evidence that inhibition of SXC by SAS can decrease network hyperexcitability induced by three distinct pharmacologic agents in the superficial layers of the cortex. Furthermore, SAS provided additional suppression of 4‐AP–induced network activity when administered with the currently prescribed AED TPM. These findings may serve as a foundation to assess the potential for SAS or other compounds that selectively target SXC as an adjuvant treatment for epilepsy. Foundation for the National Institutes of Health, Grant/Award Number: 5R01‐NS036692, R01‐NS052634 and R01CA227149