3D Electrophysiological Measurements on Cells Embedded within Fiber‐Reinforced Matrigel

Melt electrowriting of scaffolds is used to reinforce Matrigel and allow 3D electrophysiology on transfected fibroblast cells. A square pore spacing of 200 µm allows proper cell growth, handling during cell staining, and good cell accessibility by the recording electrode. This approach provides a fundamental milestone to further develop electrophysiology in 3D neuronal networks.

Abstract

2D electrophysiology is often used to determine the electrical properties of neurons. In the brain however, neurons form extensive 3D networks. Thus, performing electrophysiology in a 3D environment provides a closer situation to the physiological condition and serves as a useful tool for various applications in the field of neuroscience. In this study, 3D electrophysiology is established within a fiber‐reinforced matrix to enable fast readouts from transfected cells, which are often used as model systems for 2D electrophysiology. Using melt electrowriting (MEW) of scaffolds to reinforce Matrigel, 3D electrophysiology is performed on a glycine receptor‐transfected Ltk‐11 mouse fibroblast cell line. The glycine receptor is an inhibitory ion channel associated when mutated with impaired neuromotor behavior. The average thickness of the MEW scaffold is 141.4 ± 5.7 µm, using 9.7 ± 0.2 µm diameter fibers, and square pore spacings of 100, 200, and 400 µm. For the first time, the electrophysiological characterization of glycine receptor‐transfected cells is demonstrated with respect to agonist efficacy and potency in a 3D matrix. With the MEW scaffold reinforcement not interfering with the electrophysiological measurement, this approach can now be further adapted and developed for different kinds of neuronal cultures to study and understand pathological mechanisms under disease conditions.

http://bit.ly/2D7XMJD

Oncocytic poorly differentiated (insular) thyroid carcinoma mimicking metastatic adenocarcinoma. A case report and review of the literature

Abstract

We report the cytohistologic and immunohistochemical findings of an oncocytic variant of poorly differentiated thyroid carcinoma in a 76‐year old man with a prior history of prostatic adenocarcinoma. The man complained of a palpable nodule in the right thyroid lobe and cervical lymph node. Fine‐needle aspiration (FNA) in both cases yielded solid clusters of cells/insulae, microfollicles, and isolated atypical cells. Considering the patient's past history, an initial diagnosis of metastasis from prostate adenocarcinoma was considered. However, immunohistochemical staining of liquid‐based cytology specimens (Thin‐Prep) showed diffuse positive results for TTF‐1 and thyroglobulin. The patient underwent total thyroidectomy with bilateral neck dissection. Histologic and immunohistochemical evaluation showed a poorly differentiated oncocytic thyroid carcinoma with lymphovascular invasion and lymph node metastases. To our knowledge, this is the first description of the immunocytochemical evaluation of this rare variant of poorly differentiated thyroid carcinoma using FNA and liquid based cytology.

http://bit.ly/2THWuKS

Erratum to: Development and validation of the Charcot-Marie-Tooth Disease Infant Scale

Melissa R. Mandarakas, Manoj P. Menezes, Kristy J. Rose, Rosemary Shy, Kate Eichinger, Maria Foscan, Timothy Estilow, Rachel Kennedy, Karen Herbert, Paula Bray, Kathryn Refshauge, Monique M. Ryan, Eppie M. Yiu, Michelle Farrar, Hugo Sampaio, Isabella Moroni, Emanuela Pagliano, Davide Pareyson, Sabrina W. Yum, David N. Herrmann, Gyula Acsadi, Michael E. Shy, Joshua Burns and Oranee Sanmaneechai for the Inherited Neuropathies Consortium. Development and validation of the Charcot-Marie-Tooth Disease Infant Scale. Brain 2018; 141: 3319–3330; doi:10.1093/brain/awy280.

http://bit.ly/2QItHnv

A biallelic mutation links MYORG to autosomal-recessive primary familial brain calcification

Sir,

http://bit.ly/2VNIpNU

Brainstem spreading depolarization and cortical dynamics during fatal seizures in Cacna1a S218L mice

Abstract

Sudden unexpected death in epilepsy (SUDEP) is a fatal complication of epilepsy in which brainstem spreading depolarization may play a pivotal role, as suggested by animal studies. However, patiotemporal details of spreading depolarization occurring in relation to fatal seizures have not been investigated. In addition, little is known about behavioural and neurophysiological features that may discriminate spontaneous fatal from non-fatal seizures. Transgenic mice carrying the missense mutation S218L in the α_1A subunit of Ca_v2.1 (P/Q-type) Ca²⁺ channels exhibit enhanced excitatory neurotransmission and increased susceptibility to spreading depolarization. Homozygous Cacna1a^S218L mice show spontaneous non-fatal and fatal seizures, occurring throughout life, resulting in reduced life expectancy. To identify characteristics of fatal and non-fatal spontaneous seizures, we compared behavioural and electrophysiological seizure dynamics in freely-behaving homozygous Cacna1a^S218L mice. To gain insight on the role of brainstem spreading depolarization in SUDEP, we studied the spatiotemporal distribution of spreading depolarization in the context of seizure-related death. Spontaneous and electrically-induced seizures were investigated by video monitoring and electrophysiological recordings in freely-behaving Cacna1a^S218L and wild-type mice. Homozygous Cacna1a^S218L mice showed multiple spontaneous tonic-clonic seizures and died from SUDEP in adulthood. Death was preceded by a tonic-clonic seizure terminating with hindlimb clonus, with suppression of cortical neuronal activity during and after the seizure. Induced seizures in freely-behaving homozygous Cacna1a^S218L mice were followed by multiple spreading depolarizations and death. In wild-type or heterozygous Cacna1a^S218L mice, induced seizures and spreading depolarization were never followed by death. To identify temporal and regional features of seizure-induced spreading depolarization related to fatal outcome, diffusion-weighted MRI was performed in anaesthetized homozygous Cacna1a^S218L and wild-type mice. In homozygous Cacna1a^S218L mice, appearance of seizure-related spreading depolarization in the brainstem correlated with respiratory arrest that was followed by cardiac arrest and death. Recordings in freely-behaving homozygous Cacna1a^S218L mice confirmed brainstem spreading depolarization during spontaneous fatal seizures. These data underscore the value of the homozygous Cacna1a^S218L mouse model for identifying discriminative features of fatal compared to non-fatal seizures, and support a key role for cortical neuronal suppression and brainstem spreading depolarization in SUDEP pathophysiology.

http://bit.ly/2QNRouO

Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder

Abstract

With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.

http://bit.ly/2VTDpHN

Young Children Display Diurnal Patterns of Salivary IgA and Alpha-Amylase Expression Which Are Independent of Food Intake and Demographic Factors

Background. Salivary alpha-amylase (sAA) and salivary immunoglobulin A (sIgA) have been proposed as biomarkers for research on the mucosal immune system and on stress. Expression of both sAA and sIgA has been described to follow opposing diurnal patterns. This knowledge is crucial for the interpretation of studies using these biomarkers. Aim. It was hypothesized that sAA and sIgA display diurnal patterns in children and that this is independent of food intake or demographic factors. Methods. Whole saliva was collected from 78 healthy children (15-39 months old) in the morning and evening for two random nonconsecutive days. The samples have been analysed for sAA and sIgA. The total daily energy, fat, saturated fat, protein, carbohydrate and fibre, mineral, and vitamin consumption were analysed based on the two-day weighed food records collected by the parents. Results. It was demonstrated that most young children followed the diurnal pattern when sAA increased and sIgA decreased from morning to evening. No correlation was observed between the intake of any of the nutrients and morning or evening values for both salivary proteins. The morning and evening values of sAA and sIgA did not correlate with age, sex, Asian ethnicity, and BMI of the children. Conclusion. Diurnal patterns of sAA and sIgA exist in healthy young children and are not affected by their nutrient intake, sex, Asian ethnicity, and BMI. Scientists including sIgA and sAA in their research must consider the diurnal pattern that these markers exhibit and design the study accordingly.

http://bit.ly/2QO7IMh