Seizure Phenotype and Underlying Cellular Defects in Knock-In Models of DS (R1648C) and GEFS+ (R1648H) Epilepsy.

Mutations in the voltage-gated sodium channel gene are associated with human epilepsy disorders, but how most of these mutations alter channel properties and result in seizures is unknown. This study focuses on two different mutations occurring at one position within R1648C (R-C) is associated with the severe disorder Dravet syndrome, and R1648H (R-H), with the milder disorder GEFS+. To explore how these different mutations contribute to distinct seizure disorders, lines with the R-C or R-H mutation, or R1648R (R-R) control substitution in the fly sodium channel gene were generated by CRISPR-Cas9 gene editing.

A Behavioral Screen for Heat-Induced Seizures in Mouse Models of Epilepsy.

Transgenic mouse models have proved to be powerful tools in studying various aspects of human neurological disorders, including epilepsy. The SCN1A-associated genetic epilepsies comprise a wide spectrum of seizure disorders with incomplete penetrance and clinical variability. SCN1A mutations can result in a large variety of seizure phenotype ranging from simple, self-limited fever-associated febrile seizures (FS), moderate-level genetic epilepsy with febrile seizures plus (GEFS+) to more severe Dravet Syndrome (DS).

Interneuron Dysfunction in a New Mouse Model of SCN1A GEFS.

Advances in genome sequencing have identified over 1300 mutations in the sodium channel gene that result in genetic epilepsies. However, it still remains unclear how most individual mutations within result in seizures. A previous study has shown that the K1270T (KT) mutation, linked to genetic epilepsy with febrile seizure plus (GEFS+) in humans, causes heat-induced seizure activity associated with a temperature-dependent decrease in GABAergic neuron excitability in a knock-in model.

Seven practical strategies to add active learning to a science lecture.

Multiple research studies have shown active learning can increase student performance, reduce fail rates, and increase the success of marginalized students in STEM. In this mini-review we discuss a simple framework for planning and implementing active learning in the classroom. We provide seven strategies to support faculty members who want to implement this framework, with five suggested teaching activities and two mechanisms of creating space in the lecture to use the activities.

Comparisons of dual isogenic human iPSC pairs identify functional alterations directly caused by an epilepsy associated SCN1A mutation.

Over 1250 mutations in SCN1A, the Nav1.1 voltage-gated sodium channel gene, are associated with seizure disorders including GEFS+. To evaluate how a specific mutation, independent of genetic background, causes seizure activity we generated two pairs of isogenic human iPSC lines by CRISPR/Cas9 gene editing.

When it comes to teaching and tenure it is time to walk the walk.

Institutions should value teaching and service, and not just research, when considering faculty for promotion and tenure.

Whole-cell Recordings in Adult Brain.

Cost-effective and efficient, the fruit fly () has been used to make many key discoveries in the field of neuroscience and to model a number of neurological disorders. Great strides in understanding have been made using sophisticated molecular genetic tools and behavioral assays. Functional analysis of neural activity was initially limited to the neuromuscular junction (NMJ) and in the central nervous system (CNS) of embryos and larvae.

Reproducible and efficient generation of functionally active neurons from human hiPSCs for preclinical disease modeling.

The use of human induced pluripotent stem cell (hiPSC)-derived neuronal cultures to study the mechanisms of neurological disorders is often limited by low efficiency and high variability in differentiation of functional neurons. Here we compare the functional properties of neurons in cultures prepared with two hiPSC differentiation protocols, both plated on astroglial feeder layers. Using a protocol with an expandable intermediate stage, only a small percentage of cells with neuronal morphology were excitable by 21-23days in culture.

Aligning Practice to Policies: Changing the Culture to Recognize and Reward Teaching at Research Universities.

Recent calls for improvement in undergraduate education within STEM (science, technology, engineering, and mathematics) disciplines are hampered by the methods used to evaluate teaching effectiveness. Faculty members at research universities are commonly assessed and promoted mainly on the basis of research success. To improve the quality of undergraduate teaching across all disciplines, not only STEM fields, requires creating an environment wherein continuous improvement of teaching is valued, assessed, and rewarded at various stages of a faculty member's career.

Astrocyte-enriched feeder layers from cryopreserved cells support differentiation of spontaneously active networks of human iPSC-derived neurons.

Background: Human induced pluripotent stem cell (hiPSC)-derived neuronal cultures are a useful tool for studying the mechanisms of neurological disorders and developing novel therapeutics. While plating hiPSC-derived neuronal progenitors onto glial feeder layers prepared from rodent cortex has been reported to promote functional differentiation of neuronal networks, this has not been examined in detail.

New Method: Here we describe a method of using cryopreserved cells from primary cultures for generation of mouse astrocyte-enriched, neuron-free feeder layers that grow from 10% to 100% confluence in 1 week.

MiR-980 Is a Memory Suppressor MicroRNA that Regulates the Autism-Susceptibility Gene A2bp1.

MicroRNAs have been associated with many different biological functions, but little is known about their roles in conditioned behavior. We demonstrate that Drosophila miR-980 is a memory suppressor gene functioning in multiple regions of the adult brain. Memory acquisition and stability were both increased by miR-980 inhibition.

Model systems for studying cellular mechanisms of SCN1A-related epilepsy.

Mutations in SCN1A, the gene encoding voltage-gated sodium channel NaV1.1, cause a spectrum of epilepsy disorders that range from genetic epilepsy with febrile seizures plus to catastrophic disorders such as Dravet syndrome. To date, more than 1,250 mutations in SCN1A have been linked to epilepsy.

The Autism Spectrum Disorders Stem Cell Resource at Children's Hospital of Orange County: Implications for Disease Modeling and Drug Discovery.

The autism spectrum disorders (ASDs) comprise a set of neurodevelopmental disorders that are, at best, poorly understood but are the fastest growing developmental disorders in the United States. Because animal models of polygenic disorders such as the ASDs are difficult to validate, the derivation of induced pluripotent stem cells (iPSCs) by somatic cell reprogramming offers an alternative strategy for identifying the cellular mechanisms contributing to ASDs and the development of new treatment options. Access to statistically relevant numbers of ASD patient cell lines, however, is still a limiting factor for the field.

Knock-in model of Dravet syndrome reveals a constitutive and conditional reduction in sodium current.

Hundreds of mutations in the SCN1A sodium channel gene confer a wide spectrum of epileptic disorders, requiring efficient model systems to study cellular mechanisms and identify potential therapeutic targets. We recently demonstrated that Drosophila knock-in flies carrying the K1270T SCN1A mutation known to cause a form of genetic epilepsy with febrile seizures plus (GEFS+) exhibit a heat-induced increase in sodium current activity and seizure phenotype. To determine whether different SCN1A mutations cause distinct phenotypes in Drosophila as they do in humans, this study focuses on a knock-in line carrying a mutation that causes a more severe seizure disorder termed Dravet syndrome (DS).

A biophysical analysis of mitochondrial movement: differences between transport in neuronal cell bodies versus processes.

There is an increasing interest in factors that can impede cargo transport by molecular motors inside the cell. Although potentially relevant (Yi JY, Ori-McKenney KM, McKenney RJ, Vershinin M, Gross SP, Vallee RB. High-resolution imaging reveals indirect coordination of opposite motors and a role for LIS1 in high-load axonal transport.

Process-based expansion and neural differentiation of human pluripotent stem cells for transplantation and disease modeling.

Robust strategies for developing patient-specific, human, induced pluripotent stem cell (iPSC)-based therapies of the brain require an ability to derive large numbers of highly defined neural cells. Recent progress in iPSC culture techniques includes partial-to-complete elimination of feeder layers, use of defined media, and single-cell passaging. However, these techniques still require embryoid body formation or coculture for differentiation into neural stem cells (NSCs).

Cav3-type α1T calcium channels mediate transient calcium currents that regulate repetitive firing in Drosophila antennal lobe PNs.

Projection neurons (PNs), located in the antennal lobe region of the insect brain, play a key role in processing olfactory information. To explore how activity is regulated at the level of single PNs within this central circuit we have recorded from these neurons in adult Drosophila melanogaster brains. Our previous study demonstrated that PNs express voltage-gated calcium currents with a transient and sustained component.

A knock-in model of human epilepsy in Drosophila reveals a novel cellular mechanism associated with heat-induced seizure.

Over 40 missense mutations in the human SCN1A sodium channel gene are linked to an epilepsy syndrome termed genetic epilepsy with febrile seizures plus (GEFS+). Inheritance of GEFS+ is dominant, but the underlying cellular mechanisms remain poorly understood. Here we report that knock-in of a GEFS+ SCN1A mutation (K1270T) into the Drosophila sodium channel gene, para, causes a semidominant temperature-induced seizure phenotype.

Assessment of learning gains associated with independent exam analysis in introductory biology.

This study evaluates the impact of an independent postmidterm question analysis exercise on the ability of students to answer subsequent exam questions on the same topics. It was conducted in three sections (∼400 students/section) of introductory biology. Graded midterms were returned electronically, and each student was assigned a subset of questions answered incorrectly by more than 40% of the class to analyze as homework.

Prokineticin 2 regulates the electrical activity of rat suprachiasmatic nuclei neurons.

Neuropeptide signaling plays roles in coordinating cellular activities and maintaining robust oscillations within the mammalian suprachiasmatic nucleus (SCN). Prokineticin2 (PK2) is a signaling molecule from the SCN and involves in the generation of circadian locomotor activity. Prokineticin receptor 2 (PKR2), a receptor for PK2, has been shown to be expressed in the SCN.

Learn before lecture: A strategy that improves learning outcomes in a large introductory biology class.

Actively engaging students in lecture has been shown to increase learning gains. To create time for active learning without displacing content we used two strategies for introducing material before class in a large introductory biology course. Four to five slides from 2007/8 were removed from each of three lectures in 2009 and the information introduced in preclass worksheets or narrated PowerPoint videos.

Garage demos: using physical models to illustrate dynamic aspects of microscopic biological processes.

Colorful PowerPoint presentations with detailed drawings, micrographs, and short animations have become the standard format for illustrating the fundamental features of cell biology in large introductory classes. In this essay, we describe a low-tech tool that can be included in a standard lecture to help students visualize, understand, and remember the dynamic aspects of microscopic cell biological processes. This approach involves use of common objects, including pipe insulation and a garden hose, to illustrate basic processes such as protein folding and cloning, hence the appellation "garage demos.