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In most mouse models of disease, the outward manifestation of a disorder can be measured easily, can be assessed with a trivial test such as hind limb clasping, or can even be observed simply by comparing the gross morphological characteristics of mutant and wild-type littermates. But what if we are trying to model a disorder with a phenotype that appears only sporadically and briefly, like epileptic seizures? The purpose of this Review is to highlight the challenges of modelling epilepsy, in which the most obvious manifestation of the disorder, seizures, occurs only intermittently, possibly very rarely and often at times when the mice are not under direct observation. Over time, researchers have developed a number of ways in which to overcome these challenges, each with their own advantages and disadvantages. In this Review, we describe the genetics of epilepsy and the ways in which genetically altered mouse models have been used. We also discuss the use of induced models in which seizures are brought about by artificial stimulation to the brain of wild-type animals, and conclude with the ways these different approaches could be used to develop a wider range of anti-seizure medications that could benefit larger patient populations., Summary: This Review discusses the challenges of modelling epilepsy in mice, a condition in which the outward manifestation of the disorder appears only sporadically, and reviews possible solutions encompassing both genetic and induced models.

Synaptotagmin (SYT) 7 has emerged as key regulator of presynaptic function, but its localization and precise function in the synaptic vesicle cycle remain unclear. Here, we used iGluSnFR to optically and directly interrogate glutamate release, at the single bouton level, in SYT7 KO dissociated mouse hippocampal neurons. We analyzed asynchronous release, paired pulse facilitation, and synaptic vesicle replenishment, and found that SYT7 contributes to each of these processes to different degrees. ‘Zap-and-freeze’ electron microscopy revealed that loss of SYT7 impairs the docking of synaptic vesicles after a stimulus and the recovery of depleted synaptic vesicles after a stimulus train. To execute these functions, SYT7 must be targeted to the plasma membrane via γ-secretase-mediated cleavage of the amino terminus, followed by palmitoylation. The complex sorting itinerary of SYT7 endows this Ca2+-sensor with the ability to control crucial forms of synaptic function and plasticity. SYT7 mediated asynchronous release, paired pulse facilitation, and synaptic vesicle replenishment was observed optically at individual hippocampal synapses Localization, trafficking, and stability of SYT7 is dependent on processing by γ-secretase Short term plasticity defects arise in SYT7KOs due to decreased docking of synaptic vesicles after stimulation SYT7 promotes paired-pulse facilitation and asynchronous release via distinct mechanisms

Neurotransmitter is released synchronously and asynchronously following an action potential. Our recent study indicates that the release sites of these two phases are segregated within an active zone, with asynchronous release sites enriched near the center in mouse hippocampal synapses. Here we demonstrate that synchronous and asynchronous release sites are aligned with AMPA receptor and NMDA receptor clusters, respectively. Computational simulations indicate that this spatial and temporal arrangement of release can lead to maximal membrane depolarization through AMPA receptors, alleviating the pore-blocking magnesium leading to greater activation of NMDA receptors. Together, these results suggest that release sites are likely organized to activate NMDA receptors efficiently., Action potentials induce synchronous and asynchronous release of neurotransmitters. Here, the authors show that the synchronous and asynchronous release sites are aligned with AMPARs and NMDARs, respectively, in mouse hippocampal synapses. This organization allows efficient activation of NMDARs.

Heterozygous de novo mutations in EEF1A2, encoding the tissue-specific translation elongation factor eEF1A2, have been shown to cause neurodevelopmental disorders including often severe epilepsy and intellectual disability. The mutational profile is unusual; ~50 different missense mutations have been identified but no obvious loss of function mutations, though large heterozygous deletions are known to be compatible with life. A key question is whether the heterozygous missense mutations operate through haploinsufficiency or a gain of function mechanism, an important prerequisite for design of therapeutic strategies. In order both to address this question and to provide a novel model for neurodevelopmental disorders resulting from mutations in EEF1A2, we created a new mouse model of the D252H mutation. This mutation causes the eEF1A2 protein to be expressed at lower levels in brain but higher in muscle in the mice. We compared both heterozygous and homozygous D252H and null mutant mice using behavioural and motor phenotyping alongside molecular modelling and analysis of binding partners. Although the proteomic analysis pointed to a loss of function for the D252H mutant protein, the D252H homozygous mice were more severely affected than null homozygotes on the same genetic background. Mice that are heterozygous for the missense mutation show no behavioural abnormalities but do have sex-specific deficits in body mass and motor function. The phenotyping of our novel mouse lines, together with analysis of molecular modelling and interacting proteins, suggest that the D252H mutation results in a gain of function.

Neurotransmitter is released synchronously and asynchronously following an action potential. The release sites of these two phases are segregated within an active zone, with asynchronous release sites enriched near the center. Here we demonstrate that synchronous and asynchronous release sites are aligned with AMPA receptor and NMDA receptor clusters, respectively. Computational simulations indicate that this spatial and temporal arrangement of release ensures maximal membrane depolarization through AMPA receptors, alleviating the pore-blocking magnesium leading to greater activation of NMDA receptors. Together, these results suggest that release sites are organized to efficiently activate NMDA receptors.

Introduction The purpose of this study was to evaluate the efficacy and tolerability of carfilzomib plus irinotecan (C/I) in patients with relapsed small-cell lung cancer (SCLC). Patients and Methods Patients with SCLC who progressed after 1 platinum-containing regimen for recurrent or metastatic disease were eligible. Patients were stratified as: sensitive (SS) (progressive disease > 90 days after chemotherapy) or refractory (RS) (progressive disease 30 to 90 days after chemotherapy) and received up to 6 cycles of C/I; imaging was performed every 2 cycles. The primary endpoint was 6-month overall survival (OS). Results All 62 patients enrolled were evaluable for efficacy and adverse events. 6-month OS was 59% in the platinum SS and 54% in the platinum RS. The overall response rate was 21.6% (2.7% complete response, 18.9% partial response) in SS (n = 37) and 12.5% (all partial response) in RS (n = 25). The disease control rate was 68% (SS) and 56% (RS). Progression-free survival and OS were 3.6 months (95% confidence interval [CI], 2.6-4.6 months) and 6.9 months (95% CI, 4.3-12.3 months) in SS, and 3.3 months (95% CI, 1.8-3.9 months) and 6.8 months (95% CI, 4.1-11 months) in RS. Twenty-nine (47%) patients experienced ≥ grade 3 adverse events; 8 (12.9%) subjects had grade 4 toxicities. Three treatment-related deaths occurred: myocardial infarction (possible), lung infection (possible), and sepsis (probable). Conclusion In patients with relapsed SCLC, C/I was effective in the treatment of SS and RS. With 4.8% grade 5 toxicity, C/I is a viable option for relapsed patients with SCLC with performance status 0 to 1, particularly in platinum-resistant patients, or subjects who cannot receive immunotherapy.