An Autism-Associated Mutation Impairs Neuroligin-4 Glycosylation and Enhances Excitatory Synaptic Transmission in Human Neurons.

Neuroligins (NLGNs) are a class of postsynaptic cell adhesion molecules that interact with presynaptic neurexins (NRXNs) and regulate synapse function. NLGN4 is a member of the NLGN family and consists of a unique amino acid sequence in humans that is not evolutionarily well conserved in rodents. The human-specific NLGN4 gene has been reported to be mutated in many patients with autism and other neurodevelopmental disorders. However, it remained unclear how these mutations might alter the molecular properties of NLGN4 and affect synaptic transmission in human neurons. Here, we describe a severely autistic male patient carrying a single amino acid substitution (R101Q) in the NLGN4 gene. When expressed in HEK293 cells, the R101Q mutation in NLGN4 did not affect its binding affinity for NRXNs or its capacity to form homodimers. This mutation, however, impaired the maturation of NLGN4 protein by inhibiting N-linked glycosylation at an adjacent residue (N102), which is conserved in all NLGNs. As a result, the R101Q substitution significantly decreased the surface trafficking of NLGN4 and increased its retention in the endoplasmic reticulum and Golgi apparatus. In human neurons derived from male stem cell lines, the R101Q mutation also similarly reduced the synaptic localization of NLGN4, resulting in a loss-of-function phenotype. This mutation-induced trafficking defect substantially diminished the ability of NLGN4 to form excitatory synapses and modulate their functional properties. Viewed together, our findings suggest that the R101Q mutation is pathogenic for NLGN4 and can lead to synaptic dysfunction in autism.

The role of serotonin receptor alleles and environmental stressors in the development of post-concussive symptoms after pediatric mild traumatic brain injury.

AIM: To determine whether post-injury depressive symptoms, and pre-injury major life stressors and genetic factors (HTR1A C(-1019)G alleles; rs6295) are more common in children with mild traumatic brain injury (mTBI) who develop postconcussion syndrome (PCS) symptoms compared with children with asymptomatic mTBI. METHOD: This was a cross-sectional study of 47 symptomatic children (32 males, 15 females; mean age 14y [SD 3y 3mo]) who experienced post-concussive symptoms for 7 or more days and 42 asymptomatic children (26 males 16 females; mean age 13y 6mo [SD 3y 1mo]) after mTBI. Outcome measures were the Postconcussion Symptoms Inventory (PCSI), the Children's Depression Inventory (CDI), standard questionnaire of previous life events, and buccal DNA analysis to determine genotype and allele frequencies for the HTR1A C(-1019)G polymorphism. RESULTS: Depressive symptoms were uncommon. CDI scores did not differ between groups. Allelic and genotypic frequencies for HTR1A C(-1019)G were similar in both groups. Symptomatic children continued to have elevated PCS scores compared with asymptomatic children 1.72 (SD 0.69) years later and had experienced significantly more life stressors (Wald (1)=8.51, p=0.004). INTERPRETATION: HTR1A polymorphisms do not differ in children with PCS. Children who have experienced more significant life stresses are more likely to develop PCS symptoms after mTBI.

Preadolescent indomethacin-responsive headaches without autonomic symptoms.

OBJECTIVE: A small case series is presented of preadolescent patients with indomethacin-responsive headache. BACKGROUND: Preadolescent indomethacin-responsive headache is a rare and poorly understood entity, with few published cases in the literature. RESULTS: Two young children had similar presentations of indomethacin-responsive headaches. Both patients experienced frequent paroxysmal episodes of sudden-onset severe frontal or temporal head pain. The events lasted seconds to minutes in duration, and varied in frequency ranging from multiple episodes per week to multiple events per day. There were no associated autonomic or migrainous symptoms, and a comprehensive work-up revealed no secondary causes for the debilitating headaches. Both patients had dramatic clinical improvement with indomethacin. CONCLUSIONS: There may be a pediatric syndrome of indomethacin-responsive headache without autonomic symptoms that does not fit well within current diagnostic classifications. More research is needed to determine appropriate dosage and duration of treatment in pediatric indomethacin-responsive headache. Once secondary causes have been ruled out, a trial of indomethacin should be considered in pediatric patients presenting with severe paroxysmal headaches, even if no autonomic symptoms are present.

Maternal Metabolites Indicative of Mental Health Status during Pregnancy.

Approximately 25% of individuals report poor mental health during their pregnancy or postpartum period, which may impact fetal neurodevelopment, birth outcomes, and maternal behaviors. In the present study, maternal serum samples were collected from pregnancies at 28-32 weeks gestation from the All Our Families (Alberta, Canada) cohort and assessed using nuclear magnetic resonance spectroscopy (1H-NMR) and inductively coupled plasma-mass spectrometry (ICP-MS). Individuals with poor mental health at 34-36 weeks gestation were age-matched with mentally healthy pregnant controls. Metabolites were examined against validated self-reported mental health questionnaires for associations with depressive symptoms (Edinburgh Perinatal Depression Scale) and anxiety symptoms (Spielberger State-Trait Anxiety Inventory). 1H-NMR metabolites were identified for depression (alanine, leucine, valine, methionine, phenylalanine, glucose, lactate, 3-hydroxybutyrate, and pyruvate) and anxiety (3-hydroxybutyrate). For ICP-MS, antimony and zinc were significant for depression and anxiety, respectively. Upon false discovery rate (FDR) correction at 10%, five 1H-NMR metabolites (alanine, leucine, lactate, glucose, and phenylalanine) for depression remained significantly increased. Although results warrant further validation, the identified metabolites may serve as a predictive tool for assessing mental health during pregnancy as earlier identification has the potential to aid intervention and management of poor mental health symptomology, thus avoiding harmful consequences to both mother and offspring.

Creation and implementation of an electronic health record note for quality improvement in pediatric epilepsy: Practical considerations and lessons learned.

OBJECTIVE: To describe the development of the Pediatric Epilepsy Outcome-Informatics Project (PEOIP) at Alberta Children's Hospital (ACH), which was created to provide standardized, point-of-care data entry; near-time data analysis; and availability of outcome dashboards as a baseline on which to pursue quality improvement. METHODS: Stakeholders involved in the PEOIP met weekly to determine the most important outcomes for patients diagnosed with epilepsy, create a standardized electronic note with defined fields (patient demographics, seizure and syndrome type and frequency and specific outcomes- seizure type and frequency, adverse effects, emergency department visits, hospitalization, and care pathways for clinical decision support. These were embedded in the electronic health record from which the fields were extracted into a data display platform that provided patient- and population-level dashboards updated every 36 hours. Provider satisfaction and family experience surveys were performed to assess the impact of the standardized electronic note. RESULTS: In the last 5 years, 3,245 unique patients involving 13, 831 encounters had prospective, longitudinal, standardized epilepsy data accrued via point-of-care data entry into an electronic note as part of routine clinical care. A provider satisfaction survey of the small number of users involved indicated that the vast majority believed that the note makes documentation more efficient. A family experience survey indicated that being provided with the note was considered "valuable" or "really valuable" by 86% of respondents and facilitated communication with family members, school, and advocacy organizations. SIGNIFICANCE: The PEOIP serves as a proof of principle that information obtained as part of routine clinical care can be collected in a prospective, standardized, efficient manner and be used to construct filterable process/outcome dashboards, updated in near time (36 hours). This information will provide the necessary baseline data on which multiple of QI projects to improve meaningful outcomes for children with epilepsy will be based.

A pediatric patient with autism spectrum disorder and epilepsy using cannabinoid extracts as complementary therapy: a case report.

BACKGROUND: The pharmacological treatment for autism spectrum disorders is often poorly tolerated and has traditionally targeted associated conditions, with limited benefit for the core social deficits. We describe the novel use of a cannabidiol-based extract that incidentally improved core social deficits and overall functioning in a patient with autism spectrum disorder, at a lower dose than has been previously reported in autism spectrum disorder. CASE PRESENTATION: The parents of a 15-year-old boy, of South African descent, with autism spectrum disorder, selective mutism, anxiety, and controlled epilepsy, consulted a medical cannabis physician to trial cannabis extract to replace seizure medications. Incidentally, at a very low cannabidiol-based extract dose, he experienced unanticipated positive effects on behavioral symptoms and core social deficits. CONCLUSION: This case report provides evidence that a lower than previously reported dose of a phytocannabinoid in the form of a cannabidiol-based extract may be capable of aiding in autism spectrum disorder-related behavioral symptoms, core social communication abilities, and comorbid anxiety, sleep difficulties, and weight control. Further research is needed to elucidate the clinical role and underlying biological mechanisms of action of cannabidiol-based extract in patients with autism spectrum disorder.

Memory, reconsolidation and extinction in Lymnaea require the soma of RPeD1.

The central pattern generator (CPG) that drives aerial respiratory behaviour in Lymnaea consists of 3 neurons. One of these, RPeD1--the cell that initiates activity in the circuit, plays an absolutely necessary role as a site for memory formation, memory reconsolidation, and extinction. Using an operant conditioning training procedure that results in a long-term non-declarative memory (LTM), we decrease the occurrence of aerial respiratory behaviour. Since snails can still breathe cutaneously learning this procedure is not harmful. Concomitant with behavioural memory are changes in the spiking activity of RPeD1. Going beyond neural correlates of memory we directly show that RPeD1 is a necessary site for LTM formation. Expanding on this finding we show that this neuron is also a necessary site for memory reconsolidation and 'Pavlovian' extinction. As far as we can determine, this is the first time a single neuron has been shown to be a necessary site for these different aspects memory. RPeD1 is thus a key neuron mediating different hierarchical aspects of memory. We are now in a position to determine the necessary neuronal, molecular and proteomic events in this neuron that are causal to memory formation, reconsolidation and extinction.

Acquired infantile abducens palsy associated with anti-GM2 antibodies.

Anti-ganglioside antibodies have been associated with acquired neuropathies, including Guillain-Barré syndrome. We describe a case of acute abducens nerve palsy acquired 2 weeks after symptoms of upper respiratory tract infection and rash in a 6-month-old. Elevated anti-GM2 ganglioside immunoglobulin M antibodies were detected in the serum. The palsy slowly improved over time, although eventually surgical intervention was required. Elevated anti-GM2 immunoglobulin M antibodies have previously been reported in Guillain-Barré syndrome variants involving sensory and cranial neuropathies, but never in isolated unilateral cranial nerve VI mononeuropathy. Anti-ganglioside antibodies may play a role in the pathogenesis of postinfectious isolated abducens palsy in young children.

Reconsolidation and memory infidelity in Lymnaea.

Lymnaea stagnalis were operantly conditioned to not perform aerial respiratory behaviour in a specific context (i.e. context-1). The memory for this learned response was reactivated 3 days later in context-1. During the 1 h reconsolidation period following memory reactivation, randomly picked snails were either maintained in context-1 or exposed to a new context (i.e. context-2). One hour later in the post-reconsolidation period, snails in context-1 were placed for 1 h in context-2 and vice-versa. In neither the hypoxic reconsolidation nor the post reconsolidation periods did snails receive a reinforcing stimulus when they opened their pneumostome. All snails were blindly tested for memory 24 h later period in context-2. Only those snails that had been exposed to context-2 during the reconsolidation period exhibited 'memory' for context-2. That is, memory infidelity was observed. Snails exposed to context-2 in only the post-reconsolidation period did not show memory for context-2. The immediate cooling of snails after their exposure to the new context in the reconsolidation period blocked the formation the implanted memory. Snails trained in context-1 and exposed to context-2 in the consolidation period only, also did not have memory for context-2. However, the memory for context-1 could still be recalled following successful implantation of the 'new' memory. All data presented here are consistent with the notion that during the reconsolidation process memory can be updated.

Gone but not forgotten: the lingering effects of intermediate-term memory on the persistence of long-term memory.

Aerial respiratory behaviour can be operantly conditioned in Lymnaea stagnalis and, depending on the interval between the training sessions, memories of significantly different durations are produced. In naïve snails, a 15 min training procedure with a 30 min interval between three training sessions results in memory that persists for only 3 h (intermediate-term memory, ITM); whilst if the three 15 min training sessions are separated by a 1 h interval memory persists for 48 h (long-term memory, LTM). We found that if ITM training preceded LTM training, then LTM would persist for 24 h longer. This augmenting effect on LTM persistence could be demonstrated for up to 5 h following the last ITM training session, even though ITM was not observed at that time. However, if LTM training ensued 8 h after the last ITM training session, an augmented LTM did not occur. Extinguishing the memory produced by the ITM training procedure also prevented augmentation of LTM. That is, if an extinction procedure was given to the snails after the ITM training procedure, LTM did not persist longer than 48 h. Thus, at the behavioural level, ITM and LTM are interconnected.

Cooling blocks ITM and LTM formation and preserves memory.

In Lymnaea aerial respiratory behaviour can be operantly conditioned; snails learn not to perform this behaviour. Depending on the training procedure used, snails are competent to form either intermediate-term (ITM; lasting 1-3 h) or long-term (LTM; >4 h) memory. We found that cooling the snails for 1 h immediately after training was sufficient to block either ITM or LTM. Cooling snails for a similar period 10 or 15 min after cessation of training, failed to block ITM and LTM formation, respectively. Finally, we employed the cooling technique to extend both ITM and LTM. That is, cooling could prevent forgetting. Cooling extended LTM that normally persisted for 2 days to at least 8 days. These data are consistent with the hypothesis that forgetting is due to the learning and remembering of interfering events, and thus is an active process.

Nitric oxide mediates metabolism as well as respiratory and cardiac responses to hypoxia in the snail lymnaea stagnalis.

Lymnaea stagnalis were exposed to hypoxic and chemical challenges while ventilation, heart rate and metabolism were monitored. Hypoxia increased ventilatory behavior, but this response was eliminated by immersion in 0.75 mM nitric oxide synthase (NOS) inhibitor, 7-nitroindazole (7 NI). 7 NI also suppressed ventilatory behavior under normoxia. 10.0 mM L-arginine (ARG, the NOS substrate) increased ventilatory behavior under normoxia, but dampened the hypoxic response. The heart-rate response to NOS inhibition exhibited dose-dependent contradictory characteristics. Under both normoxia and hypoxia 0.25 mM 7 NI increased heart rate, while 0.75 mM 7 NI suppressed it. The effect of 0.50 mM 7 NI depended on whether normoxia or hypoxia was coincident; under normoxia 0.50 mM 7 NI increased heart rate, while under hypoxia this concentration suppressed heart rate. Exposure to ARG did not elicit dose-dependent contradictory responses. Heart rate increased when treated with 10.0 mM ARG under normoxia and hypoxia, while 1.0 mM ARG increased heart rate only under hypoxia. Metabolic responses to NOS inhibition also exhibited dose-dependent contradictory changes. V.O2 decreased over 60% in response to 0.75 mM 7 NI, and baseline V.O2 was restored when exposure ceased. In contrast, 0.25 mM 7 NI increased V.O2 10%, and the increase continued after exposure ceased. 0.50 mM 7 NI decreased V.O2 40%, but V.O2 increased when exposure ceased. ARG had only the effect of increasing V.O2, and only at 10.0 mM concentration. Based on these results and on NO's known role as a neuromodulator, we conclude that the cardio-respiratory responses to hypoxia are, in part, mediated by NO.