Chromosome X-wide common variant association study in autism spectrum disorder.

Autism spectrum disorder (ASD) displays a notable male bias in prevalence. Research into rare (<0.1) genetic variants on the X chromosome has implicated over 20 genes in ASD pathogenesis, such as MECP2, DDX3X, and DMD.

Genetic variants in DDX53 contribute to autism spectrum disorder associated with the Xp22.11 locus.

Autism spectrum disorder (ASD) exhibits an ∼4:1 male-to-female sex bias and is characterized by early-onset impairment of social/communication skills, restricted interests, and stereotyped behaviors. Disruption of the Xp22.11 locus has been associated with ASD in males.

Chromosome X-Wide Common Variant Association Study (XWAS) in Autism Spectrum Disorder.

Autism Spectrum Disorder (ASD) displays a notable male bias in prevalence. Research into rare (<0.1) genetic variants on the X chromosome has implicated over 20 genes in ASD pathogenesis, such as , , and .

Disruption of DDX53 coding sequence has limited impact on iPSC-derived human NGN2 neurons.

Background: The X-linked PTCHD1 locus is strongly associated with autism spectrum disorder (ASD). Males who carry chromosome microdeletions of PTCHD1 antisense long non-coding RNA (PTCHD1-AS)/DEAD-box helicase 53 (DDX53) have ASD, or a sub-clinical form called Broader Autism Phenotype. If the deletion extends beyond PTCHD1-AS/DDX53 to the next gene, PTCHD1, which is protein-coding, the individuals typically have ASD and intellectual disability (ID).

Specific Role for GSK3α in Limiting Long-Term Potentiation in CA1 Pyramidal Neurons of Adult Mouse Hippocampus.

Glycogen synthase kinase-3 (GSK3) mediates phosphorylation of several hundred proteins, and its aberrant activity is associated with an array of prevalent disorders. The two paralogs, GSK3α and GSK3β, are expressed ubiquitously and fulfill common as well as unique tasks throughout the body. In the CNS, it is established that GSK3 is involved in synaptic plasticity.

GSK-3β regulates the synaptic expression of NMDA receptors via phosphorylation of phosphatidylinositol 4 kinase type IIα.

Deregulation of GSK-3β is strongly implicated in a variety of serious brain conditions, such as Alzheimer disease, bipolar disorder and schizophrenia. To understand how GSK-3β becomes dysregulated in these conditions, it is important to understand its physiological functions in the central nervous system. In this context, GSK-3β plays a role in the induction of NMDA receptor-dependent long-term depression (LTD) and several substrates for GSK-3β have been identified in this form of synaptic plasticity, including KLC-2, PSD-95 and tau.

The Probability of Neurotransmitter Release Governs AMPA Receptor Trafficking via Activity-Dependent Regulation of mGluR1 Surface Expression.

A major mechanism contributing to synaptic plasticity involves alterations in the number of AMPA receptors (AMPARs) expressed at synapses. Hippocampal CA1 synapses, where this process has been most extensively studied, are highly heterogeneous with respect to their probability of neurotransmitter release, P(r). It is unknown whether there is any relationship between the extent of plasticity-related AMPAR trafficking and the initial P(r) of a synapse.

Exorhodopsin and melanopsin systems in the pineal complex and brain at early developmental stages of Atlantic halibut (Hippoglossus hippoglossus).

The complexity of the nonvisual photoreception systems in teleosts has just started to be appreciated, with colocalization of multiple photoreceptor types with unresolved functions. Here we describe an intricate expression pattern of melanopsins in early life stages of the marine flat fish Atlantic halibut (Hippoglossus hippoglossus), a period when the unpigmented brain is directly exposed to environmental photons. We show a refined and extensive expression of melanopsins in the halibut brain already at the time of hatching, long before the eyes are functional.

Shank mutant mice as an animal model of autism.

In this review, we focus on the role of the Shank family of proteins in autism. In recent years, autism research has been flourishing. With genetic, molecular, imaging and electrophysiological studies being supported by behavioural studies using animal models, there is real hope that we may soon understand the fundamental pathology of autism.

A pivotal role of GSK-3 in synaptic plasticity.

Glycogen synthase kinase-3 (GSK-3) has many cellular functions. Recent evidence suggests that it plays a key role in certain types of synaptic plasticity, in particular a form of long-term depression (LTD) that is induced by the synaptic activation of N-methyl-D-aspartate receptors (NMDARs). In the present article we summarize what is currently known concerning the roles of GSK-3 in synaptic plasticity at both glutamatergic and GABAergic synapses.

PI3Kγ is required for NMDA receptor-dependent long-term depression and behavioral flexibility.

Phosphatidylinositol 3-kinase (PI3K) has been implicated in synaptic plasticity and other neural functions in the brain. However, the role of individual PI3K isoforms in the brain is unclear. We investigated the role of PI3Kγ in hippocampal-dependent synaptic plasticity and cognitive functions.

Mechanisms involved in cholesterol-induced neuronal insulin resistance.

Insulin receptors (IRs) are highly expressed in the central nervous system (CNS) and play an important role in normal brain functions, such as learning and memory. Due to the increasing rate of obesity in western societies and overall high fat diets, the incidents of neuronal insulin resistance is also on the rise, but the underlying mechanism is still poorly characterized. We found that cholesterol treatment produces robust insulin signaling resistance that is characterized by the marked reduction in insulin-stimulated tyrosine phosphorylation of the IR and its downstream targets insulin receptor substrate 1 (IRS1) and 2 (IRS2).

Mechanisms involved in the reduction of GABAA receptor alpha1-subunit expression caused by the epilepsy mutation A322D in the trafficking-competent receptor.

A mutation in the alpha1-subunit (A322D) of GABA(A)Rs is responsible for juvenile myoclonic epilepsy in a large Canadian family. Previous work has identified that this mutant affects the cell expression and function of recombinant GABA(A)Rs, expressed in HEK293 cells. Here we have extended these observations by showing that the mutation promotes association with the endoplasmic reticulum chaperone calnexin and accelerates the degradation rate of the subunits approximately 2.

LTP inhibits LTD in the hippocampus via regulation of GSK3beta.

Glycogen synthase kinase-3 (GSK3) has been implicated in major neurological disorders, but its role in normal neuronal function is largely unknown. Here we show that GSK3beta mediates an interaction between two major forms of synaptic plasticity in the brain, N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) and NMDA receptor-dependent long-term depression (LTD). In rat hippocampal slices, GSK3beta inhibitors block the induction of LTD.

Ontogeny of ultraviolet-sensitive cones in the retina of rainbow trout (Oncorhynchus mykiss).

In order to facilitate emerging models of retinal development, we developed electroretinogram and in situ hybridization protocols to examine the ontogeny of photoreceptors in the retina of a land-locked salmonid, the rainbow trout (Oncorhynchus mykiss). We cloned cDNA fragments corresponding to the rod opsin and each of the four cone opsin gene families, which we utilized to produce riboprobes. We established the specificity of the in situ hybridization protocol by examining subcellular signal localization and through double-labeling experiments.