A comparison of the antiepileptogenic efficacy of two rationally chosen multitargeted drug combinations in a rat model of posttraumatic epilepsy.

Post-traumatic epilepsy (PTE) is a recurrent and often drug-refractory seizure disorder caused by traumatic brain injury (TBI). No single drug treatment prevents PTE, but preventive drug combinations that may prophylax against PTE have not been studied. Based on a systematic evaluation of rationally chosen drug combinations in the intrahippocampal kainate (IHK) mouse model of acquired epilepsy, we identified two multi-targeted drug cocktails that exert strong antiepileptogenic effects. The first, a combination of levetiracetam (LEV) and topiramate, only partially prevented spontaneous recurrent seizures in the model. We therefore added atorvastatin (ATV) to the therapeutic cocktail (TC) to increase efficacy, forming "TC-001". The second cocktail - a combination of LEV, ATV, and ceftriaxone, termed "TC-002" - completely prevented epilepsy in the mouse IHK model. In the present proof-of-concept study, we tested whether the two drug cocktails prevent epilepsy in a rat PTE model in which recurrent electrographic seizures develop after severe rostral parasagittal fluid percussion injury (FPI). Following FPI, rats were either treated over 3-4 weeks with vehicle or drug cocktails, starting either 1 or 4-6 h after the injury. Using mouse doses of TC-001 and TC-002, no significant antiepileptogenic effect was obtained in the rat PTE model. However, when using allometric scaling of drug doses to consider the differences in body surface area between mice and rats, PTE was prevented by TC-002. Furthermore, the latter drug cocktail partially prevented the loss of perilesional cortical parvalbumin-positive GABAergic interneurons. Plasma and brain drug analysis showed that these effects of TC-002 occurred at clinically relevant levels of the individual TC-002 drug components. In silico analysis of drug-drug brain protein interactions by the STITCH database indicated that TC-002 impacts a larger functional network of epilepsy-relevant brain proteins than each drug alone, providing a potential network pharmacology explanation for the observed antiepileptogenic and neuroprotective effects observed with this combination.

High mortality rates among COVID-19 intensive care patients in Iraq: insights from a retrospective cohort study at Médecins Sans Frontières supported hospital in Baghdad.

Background: The Coronavirus Disease 2019 (COVID-19) pandemic has highlighted the challenges of the healthcare system in Iraq, which has limited intensive care unit beds, medical personnel, and equipment, contributing to high infection rates and mortality. The main purpose of the study was to describe the clinical characteristics, the length of Intensive Care Unit (ICU) stay, and the mortality outcomes of COVID-19 patients admitted to the ICU during the first wave and two subsequent surges, spanning from September 2020 to October 2021, in addition to identify potential risk factors for ICU mortality. Methods: This retrospective cohort study analyzed data from COVID-19 patients admitted to the COVID-19 ICU at Al-Kindi Ministry of Health hospital in Baghdad, Iraq, between September 2020 and October 2021. Results: The study included 936 COVID-19 patients admitted to the ICU at Al-Kindi Hospital. Results showed a high mortality rate throughout all waves, with 60% of deaths due to respiratory failure. Older age, male gender, pre-existing medical conditions, ICU procedures, and complications were associated with increased odds of ICU mortality. The study also found a decrease in the number of complications and ICU procedures between the first and subsequent waves. There was no significant difference in the length of hospital stay between patients admitted during different waves. Conclusion: Despite improvements in critical care practices, the mortality rate did not significantly decrease during the second and third waves of the pandemic. The study highlights the challenges of high mortality rates among critical COVID-19 patients in low-resource settings and the importance of effective data collection to monitor clinical presentations and identify opportunities for improvement in ICU care.

Seizure reduction in TSC2-mutant mouse model by an mTOR catalytic inhibitor.

OBJECTIVE: Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder caused by autosomal-dominant pathogenic variants in either the TSC1 or TSC2 gene, and it is characterized by hamartomas in multiple organs, such as skin, kidney, lung, and brain. These changes can result in epilepsy, learning disabilities, and behavioral complications, among others. The mechanistic link between TSC and the mechanistic target of the rapamycin (mTOR) pathway is well established, thus mTOR inhibitors can potentially be used to treat the clinical manifestations of the disorder, including epilepsy. METHODS: In this study, we tested the efficacy of a novel mTOR catalytic inhibitor (here named Tool Compound 1 or TC1) previously reported to be more brain-penetrant compared with other mTOR inhibitors. Using a well-characterized hypomorphic Tsc2 mouse model, which displays a translationally relevant seizure phenotype, we tested the efficacy of TC1. RESULTS: Our results show that chronic treatment with this novel mTOR catalytic inhibitor (TC1), which affects both the mTORC1 and mTORC2 signaling complexes, reduces seizure burden, and extends the survival of Tsc2 hypomorphic mice, restoring species typical weight gain over development. INTERPRETATION: Novel mTOR catalytic inhibitor TC1 exhibits a promising therapeutic option in the treatment of TSC.

Depressed glutamate transporter 1 expression in a mouse model of Dravet syndrome.

Dravet syndrome (DS) is a monogenic, often refractory, epilepsy resultant from SCN1A haploinsufficiency in humans. A novel therapeutic target in DS that can be engaged in isolation or as adjunctive therapy is highly desirable. Here, we demonstrate reduced expression of the rodent glutamate transporter type 1 (GLT-1) in a DS mouse model, and in wild type mouse strains where Scn1a haploinsufficiency is most likely to cause epilepsy, indicating that GLT-1 depression may play a role in DS seizures. As GLT-1 can be upregulated by common and safe FDA-approved medications, this strategy may be an attractive, viable, and novel avenue for DS treatment.

A 5 item version of the Workplace Activity Limitation Scale successfully identifies impaired work productivity in rheumatoid arthritis patients: A split-sample factor analysis approach.

BACKGROUND: There is a growing interest in studying the effects of arthritis on a person's work productivity using a growing variety of outcome indicators. OBJECTIVES: To develop a valid and reliable shortened version of the Workplace Activity Limitation Scale 12 (WALS-12) for assessing work productivity limitations in rheumatoid arthritis (RA) patients. METHODS: A cross-sectional study involving 277 RA patients was conducted. An exploratory factor analysis on WALS-12 was used for item reduction on the first sample. Then confirmatory factor analysis (CFA) was run to establish the best fit indices of the reduced version. On the second sample, CFA and linear discriminant analysis were performed to assess the diagnostic performance and discriminant ability of the reduced form. A Bland-Altman method was used to find the agreement between the WALS-12 and the reduced one. RESULTS: The WALS-12 was reduced to 5 items. The Cronbach α was 0.817, with a composite reliability of 0.715. The Spearman rho correlation coefficient ranged between 0.675 and 0.795 for WALS-5, which was higher for the scale items with their domains than the correlation of WALS-5 with the domains of Work Limitations Questionnaire-25. Also, the root square of the average variant extracted from WALS-5 was 0.802. WALS-5 showed excellent discriminant ability with an area under the curve of 0.98 (P < .001), sensitivity of 97%, specificity of 82%, and accuracy of 94%. The reduced version WALS-5 was in agreement with the original version WALS-12. CONCLUSIONS: WALS-5 is a valid and reliable tool to assess the work productivity limitations in RA patients.

N-acetylcysteine treatment mitigates loss of cortical parvalbumin-positive interneuron and perineuronal net integrity resulting from persistent oxidative stress in a rat TBI model.

Traumatic brain injury (TBI) increases cerebral reactive oxygen species production, which leads to continuing secondary neuronal injury after the initial insult. Cortical parvalbumin-positive interneurons (PVIs; neurons responsible for maintaining cortical inhibitory tone) are particularly vulnerable to oxidative stress and are thus disproportionately affected by TBI. Systemic N-acetylcysteine (NAC) treatment may restore cerebral glutathione equilibrium, thus preventing post-traumatic cortical PVI loss. We therefore tested whether weeks-long post-traumatic NAC treatment mitigates cortical oxidative stress, and whether such treatment preserves PVI counts and related markers of PVI integrity and prevents pathologic electroencephalographic (EEG) changes, 3 and 6 weeks after fluid percussion injury in rats. We find that moderate TBI results in persistent oxidative stress for at least 6 weeks after injury and leads to the loss of PVIs and the perineuronal net (PNN) that surrounds them as well as of per-cell parvalbumin expression. Prolonged post-TBI NAC treatment normalizes the cortical redox state, mitigates PVI and PNN loss, and - in surviving PVIs - increases per-cell parvalbumin expression. NAC treatment also preserves normal spectral EEG measures after TBI. We cautiously conclude that weeks-long NAC treatment after TBI may be a practical and well-tolerated treatment strategy to preserve cortical inhibitory tone post-TBI.

Antioxidant and Anticancer Activities of Heart Components Extracted from Iraqi Phoneix Dactylifera Chick.

BACKGROUND: Breast cancer is one of the most frequent malignancies in women, and it is a major cause of cancer death worldwide, as well as one of the leading causes of cancer mortality. Traditional herbal therapy has been widely used in some developing countries as a complementary and alternative technique. Because of their low toxicity, medicinal edible plants have been allowed to minimize the risk of breast cancer and other diseases. The heart of Phoenix dactylifera is a well-known, safe, and common edible part of the P. dactylifera plant (Hilawi variety). The biological properties of heart of P. dactylifera are unclear, and the appeal warrants further investigation. The aim of this study is to look into the chemical compositions, antioxidant and anticancer properties of heart of P. dactylifera extract obtained via microwave-assisted extraction. METHODS: Microwave-assisted extraction, ethanol solvent, gas chromatography-mass spectroscopy (GC-MS) analysis, DPPH assay, MTT assay, acridine orange/ethidium bromide staining, cell cycle, reactive oxygen species, and apoptosis were all used to evaluate the activity of heart of P. dactylifera. RESULTS: GC-MS was used to identify the chemical compositions of heart of P. dactylifera extract, which revealed about 15 bioactive compounds. The antioxidant activity of heart of P. dactylifera extract was determined to have an IC50 value of 114.2 µg/ml. The cytotoxicity was measured using MCF-7 cells, and the IC50 was reported to be 620.1 µg/ml. The cell cycle was arrested at the G1 gate, resulting in the formation of reactive oxygen species and apoptosis. CONCLUSION: The findings suggested that regular consumption of P. dactylifera heart components is important for nutrition and immune system support in the prevention of breast cancer, and that more research into molecular apoptotic pathways is needed.

Gas Chromatography-Mass Spectrometry Analysis of Bioactive Compounds of Iraqi Truffle Terfezia claveryi (Ascomycetes), Synthesis of Silver Nanoparticles, and Appraisal of Its Biological Activities.

Microwave-assisted extraction (MAE) is a highly selective method that reduces the time and number of solvents used, has high efficiency, and is environmentally friendly. This study aimed to evaluate the antioxidant, anticancer, and antibacterial activities of Iraqi Terfezia claveryi desert truffle extract and silver nanoparticles by MAE using water and hexane as extraction solvents. Chemical compositions were identified by gas chromatography-mass spectrometry. Silver nanoparticles were characterized by field emission scanning electron microscopy. Antioxidant activity was assessed with the 2,2-diphenyl-1-picrylhydrazyl method. Antibacterial activity was evaluated against four types of pathogenic bacteria, and anticancer activity was also assessed. The T. claveryi hexane extract showed approximately 18 bioactive compounds, with an antioxidant half-maximal inhibitory concentration of 6.896 µg/mL. This extract also had significant antibacterial action against Escherichia coli and Pseudomonas aeruginosa. A cytotoxicity test of the hexane extract showed moderate toxicity against hepatocellular carcinoma mouse (HCAM) liver cancer cells. Acridine orange/ ethidium bromide staining showed apoptosis and DNA damage in HCAM cells treated with the hexane extract. The results of this study suggest that components of the T. claveryi wild desert truffle could have important nutrition functions that might support the immune system in fighting liver diseases when taken in daily regular doses.

Investigations of Phytoconstituents, Antioxidant and Anti-Liver Cancer Activities of Saueda monoica Forssk Extracted by Microwave-Assisted Extraction.

BACKGROUND: Wild edible plants are good sources for bioactive compounds, vitamins, and minerals with various applications. They can play a role in supporting the immune system and are highly beneficial as resources. Suaeda monoica Forssk is a wild edible plant that grows in Iraq and it's biological activities have not yet reported. METHODS: Saueda monoica Forssk bioactive compounds were extracted by a microwave-assisted extraction method using ethanol as a solvent, and its chemical composition was analyzed by GC-MS. The biological activities were evaluated via antioxidant, anti-liver-cancer, antibacterial, and toxicity tests in vitro. RESULTS: The results of GC-MS analysis showed that there were about 20 bioactive compounds. The most abundant compound was N,N-Dimethylglycine methyl ester, followed by 9,12,15-Octadecatrienoic acid, n-Hexadecanoic acid, and N,N-Dimethylglycine. The antioxidant activity of the ethanol extract of the plant showed a significant IC50. The extract of S. monoica against liver cancer cells (HCAM) showed significant toxicity. Flow cytometric analysis showed a significant induced apoptosis and cell cycle arrested at G1 phase. CONCLUSIONS: The results indicated the significance of the components of Iraqi S. monoica Forssk by MAE method as a potential food supplement in nutrition systems to prevent liver cancer and enhance the liver's defense against diseases.
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Increase in Seizure Susceptibility After Repetitive Concussion Results from Oxidative Stress, Parvalbumin-Positive Interneuron Dysfunction and Biphasic Increases in Glutamate/GABA Ratio.

Chronic symptoms indicating excess cortical excitability follow mild traumatic brain injury, particularly repetitive mild traumatic brain injury (rmTBI). Yet mechanisms underlying post-traumatic excitation/inhibition (E/I) ratio abnormalities may differ between the early and late post-traumatic phases. We therefore measured seizure threshold and cortical gamma-aminobutyric acid (GABA) and glutamate (Glu) concentrations, 1 and 6 weeks after rmTBI in mice. We also analyzed the structure of parvalbumin-positive interneurons (PVIs), their perineuronal nets (PNNs), and their electroencephalography (EEG) signature (gamma frequency band power). For mechanistic insight, we measured cortical oxidative stress, reflected in the reduced/oxidized glutathione (GSH/GSSG) ratio. We found that seizure susceptibility increased both early and late after rmTBI. However, whereas increased Glu dominated the E/I 1 week after rmTBI, Glu concentration normalized and the E/I was instead characterized by depressed GABA, reduced per-PVI parvalbumin expression, and reduced gamma EEG power at the 6-week post-rmTBI time point. Oxidative stress was increased early after rmTBI, where transient PNN degradation was noted, and progressed throughout the monitoring period. We conclude that GSH depletion, perhaps triggered by early Glu-mediated excitotoxicity, leads to late post-rmTBI loss of PVI-dependent cortical inhibitory tone. We thus propose dampening of Glu signaling, maintenance of redox state, and preservation of PVI inhibitory capacity as therapeutic targets for post-rmTBI treatment.

Diagnostic Accuracy of Non-Invasive Thermal Evaluation of Ventriculoperitoneal Shunt Flow in Shunt Malfunction: A Prospective, Multi-Site, Operator-Blinded Study.

BACKGROUND: Thermal flow evaluation (TFE) is a non-invasive method to assess ventriculoperitoneal shunt function. Flow detected by TFE is a negative predictor of the need for revision surgery. Further optimization of testing protocols, evaluation in multiple centers, and integration with clinical and imaging impressions prompted the current study. OBJECTIVE: To compare the diagnostic accuracy of 2 TFE protocols, with micropumper (TFE+MP) or without (TFE-only), to neuro-imaging in patients emergently presenting with symptoms concerning for shunt malfunction. METHODS: We performed a prospective multicenter operator-blinded trial of a consecutive series of patients who underwent evaluation for shunt malfunction. TFE was performed, and preimaging clinician impressions and imaging results were recorded. The primary outcome was shunt obstruction requiring neurosurgical revision within 7 d. Non-inferiority of the sensitivity of TFE vs neuro-imaging for detecting shunt obstruction was tested using a prospectively determined a priori margin of -2.5%. RESULTS: We enrolled 406 patients at 10 centers. Of these, 68/348 (20%) evaluated with TFE+MP and 30/215 (14%) with TFE-only had shunt obstruction. The sensitivity for detecting obstruction was 100% (95% CI: 88%-100%) for TFE-only, 90% (95% CI: 80%-96%) for TFE+MP, 76% (95% CI: 65%-86%) for imaging in TFE+MP cohort, and 77% (95% CI: 58%-90%) for imaging in the TFE-only cohort. Difference in sensitivities between TFE methods and imaging did not exceed the non-inferiority margin. CONCLUSION: TFE is non-inferior to imaging in ruling out shunt malfunction and may help avoid imaging and other steps. For this purpose, TFE only is favored over TFE+MP.

Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy?

Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.

Transcranial magnetic stimulation tracks subminute changes in cortical excitability during propofol anesthesia.

Automated anesthesia systems that continuously monitor cortical excitability (CE) changes to govern drug infusion rates, are desirable. Paired-pulse transcranial magnetic stimulation (ppTMS), with electromyography (EMG), provides noninvasive CE measures. We tested whether, and with what temporal resolution, ppTMS-EMG detects dose-dependent CE in rats anesthetized with continuous intravenous propofol. Motor-evoked potentials (MEPs) were recorded every 20 seconds as either propofol bolus or change in infusion rate was applied. ppTMS-derived measures varied in direct proportion to propofol dose with subminute temporal resolution. We conclude that ppTMS-EMG enables real-time markers of target engagement by anesthetics that may be incorporated into an automated device.

Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model.

Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a ß-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.

Noninvasive Thermal Evaluation of Ventriculoperitoneal Shunt Patency and Cerebrospinal Fluid Flow Using a Flow Enhancing Device.

BACKGROUND: While a noninvasive flow determination would be desirable in the diagnosis of cerebrospinal fluid shunt malfunction, existing studies have not yet defined a role for thermal flow detection. OBJECTIVE: To evaluate a revised test protocol using a micropumper designed to transiently enhance flow during thermal testing to determine whether thermal detection of flow is associated with progression to shunt revision surgery. METHODS: Eighty-two unique tests were performed in 71 shunts. The primary outcome, need for revision within 7 d of testing, was compared with results of micropumper-augmented thermal flow detection. Statistical analysis was based on blind interpretation of test results and raw temperature data recorded during testing. RESULTS: The test was sensitive (73%) and specific (68%) in predicting need for revision, with 5.6-fold higher probability of revision when flow was not detected. Negative predictive value in our sample was 94.2%. The probability of not requiring revision increased with increasing total temperature drop. Analysis of various possible thresholds showed that the optimal temperature cutoff may be lower than suggested by the manufacturer (0.125°C vs 0.2°C). CONCLUSION: This is the first study to report a strong association between thermal flow evaluation and a clinical impression that a shunt is not malfunctioning. The current recommended threshold may increase the false positive rate unnecessarily, and as clinicians gain experience with the method, they may find value in examining the temperature curves themselves. Multicenter studies are suggested to further define a role for this diagnostic test.

Electrographic spikes are common in wildtype mice.

High-voltage rhythmic electroencephalographic (EEG) spikes have been recorded in wildtype (WT) rats during periods of light slow-wave sleep and passive wakefulness. The source of this activity is unclear but has been attributed to either an inherent form of absence epilepsy or a normal feature of rodent sleep EEG. In contrast, little is known about epileptiform spikes in WT mice. We thus characterize and quantify epileptiform discharges in WT mice for the first time. Thirty-six male WT C57 mice with 24-h wireless telemetry video-EEG recordings were manually scored by blinded reviewers to mark individual spikes and spike trains. Epileptiform spikes were detected in 100% of the recorded WT mice, and spike trains of at least three spikes were recorded in 90% of mice. The spikes were more frequent during the day than at night and were inversely correlated to each animal's locomotor activity. However, the discharges were not absent during active nighttime periods. These discharges may indicate a baseline tendency toward epileptic seizures or perhaps are benign variants of normal rodent background EEG. Nevertheless, a better understanding of baseline WT EEG activity will aid in differentiating pathological and normal EEG activity in mouse epilepsy models.

Replicable in vivo physiological and behavioral phenotypes of the Shank3B null mutant mouse model of autism.

BACKGROUND: Autism spectrum disorder (ASD) is a clinically and biologically heterogeneous condition characterized by social, repetitive, and sensory behavioral abnormalities. No treatments are approved for the core diagnostic symptoms of ASD. To enable the earliest stages of therapeutic discovery and development for ASD, robust and reproducible behavioral phenotypes and biological markers are essential to establish in preclinical animal models. The goal of this study was to identify electroencephalographic (EEG) and behavioral phenotypes that are replicable between independent cohorts in a mouse model of ASD. The larger goal of our strategy is to empower the preclinical biomedical ASD research field by generating robust and reproducible behavioral and physiological phenotypes in animal models of ASD, for the characterization of mechanistic underpinnings of ASD-relevant phenotypes, and to ensure reliability for the discovery of novel therapeutics. Genetic disruption of the SHANK3 gene, a scaffolding protein involved in the stability of the postsynaptic density in excitatory synapses, is thought to be responsible for a relatively large number of cases of ASD. Therefore, we have thoroughly characterized the robustness of ASD-relevant behavioral phenotypes in two cohorts, and for the first time quantified translational EEG activity in Shank3B null mutant mice. METHODS: In vivo physiology and behavioral assays were conducted in two independently bred and tested full cohorts of Shank3B null mutant (Shank3B KO) and wildtype littermate control (WT) mice. EEG was recorded via wireless implanted telemeters for 7 days of baseline followed by 20 min of recording following pentylenetetrazol (PTZ) challenge. Behaviors relevant to the diagnostic and associated symptoms of ASD were tested on a battery of established behavioral tests. Assays were designed to reproduce and expand on the original behavioral characterization of Shank3B KO mice. Two or more corroborative tests were conducted within each behavioral domain, including social, repetitive, cognitive, anxiety-related, sensory, and motor categories of assays. RESULTS: Relative to WT mice, Shank3B KO mice displayed a dramatic resistance to PTZ seizure induction and an enhancement of gamma band oscillatory EEG activity indicative of enhanced inhibitory tone. These findings replicated in two separate cohorts. Behaviorally, Shank3B KO mice exhibited repetitive grooming, deficits in aspects of reciprocal social interactions and vocalizations, and reduced open field activity, as well as variable deficits in sensory responses, anxiety-related behaviors, learning and memory. CONCLUSIONS: Robust animal models and quantitative, replicable biomarkers of neural dysfunction are needed to decrease risk and enable successful drug discovery and development for ASD and other neurodevelopmental disorders. Complementary to the replicated behavioral phenotypes of the Shank3B mutant mouse is the new identification of a robust, translational in vivo neurophysiological phenotype. Our findings provide strong evidence for robustness and replicability of key translational phenotypes in Shank3B mutant mice and support the usefulness of this mouse model of ASD for therapeutic discovery.

Transcranial Magnetic and Direct Current Stimulation in Children.

Promising results in adult neurologic and psychiatric disorders are driving active research into transcranial brain stimulation techniques, particularly transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), in childhood and adolescent syndromes. TMS has realistic utility as an experimental tool tested in a range of pediatric neuropathologies such as perinatal stroke, depression, Tourette syndrome, and autism spectrum disorder (ASD). tDCS has also been tested as a treatment for a number of pediatric neurologic conditions, including ASD, attention-deficit/hyperactivity disorder, epilepsy, and cerebral palsy. Here, we complement recent reviews with an update of published TMS and tDCS results in children, and discuss developmental neuroscience considerations that should inform pediatric transcranial stimulation.

Trajectory of Parvalbumin Cell Impairment and Loss of Cortical Inhibition in Traumatic Brain Injury.

Many neuropsychiatric symptoms that follow traumatic brain injury (TBI), including mood disorders, sleep disturbance, chronic pain, and posttraumatic epilepsy (PTE) are attributable to compromised cortical inhibition. However, the temporal trajectory of cortical inhibition loss and its underlying mechanisms are not known. Using paired-pulse transcranial magnetic stimulation (ppTMS) and immunohistochemistry, we tracked functional and cellular changes of cortical inhibitory network elements after fluid-percussion injury (FPI) in rats. ppTMS revealed a progressive loss of cortical inhibition as early as 2 weeks after FPI. This profile paralleled the increasing levels of cortical oxidative stress, which was accompanied by a gradual loss of parvalbumin (PV) immunoreactivity in perilesional cortex. Preceding the PV loss, we identified a degradation of the perineuronal net (PNN)-a specialized extracellular structure enwrapping cortical PV-positive (PV+) inhibitory interneurons which binds the PV+ cell maintenance factor, Otx2. The trajectory of these impairments underlies the reduced inhibitory tone, which can contribute to posttraumatic neurological conditions, such as PTE. Taken together, our results highlight the use of ppTMS as a biomarker to track the course of cortical inhibitory dysfunction post-TBI. Moreover, the neuroprotective role of PNNs on PV+ cell function suggests antioxidant treatment or Otx2 enhancement as a promising prophylaxis for post-TBI symptoms.