Modeling the quantitative nature of neurodevelopmental disorders using Collaborative Cross mice

Background: Animal models for neurodevelopmental disorders (NDD) generally rely on a single genetic mutation on a fixed genetic background. Recent human genetic studies however indicate that a clinical diagnosis with ASDAutism Spectrum Disorder (ASD) is almost always associated with multiple genetic fore- and background changes. The translational value of animal model studies would be greatly enhanced if genetic insults could be studied in a more quantitative framework across genetic backgrounds. / Methods: We used the Collaborative Cross (CC), a novel mouse genetic reference population, to investigate the quantitative genetic architecture of mouse behavioral phenotypes commonly used in animal models for NDD. / Results: Classical tests of social recognition and grooming phenotypes appeared insufficient for quantitative studies due to genetic dilution and limited heritability. In contrast, digging, locomotor activity, and stereotyped exploratory patterns were characterized by continuous distribution across our CC sample and also mapped to quantitative trait loci containing genes associated with corresponding phenotypes in human populations. / Conclusions: These findings show that the CC can move animal model studies beyond comparative single gene-single background designs, and point out which type of behavioral phenotypes are most suitable to quantify the effect of developmental etiologies across multiple genetic backgrounds

A review of abnormalities in the perception of visual illusions in schizophrenia

Specific abnormalities of vision in schizophrenia have been observed to affect high-level and some low-level integration mechanisms, suggesting that people with schizophrenia may experience anomalies across different stages in the visual system affecting either early or late processing or both. Here, we review the research into visual illusion perception in schizophrenia and the issues which previous research has faced. One general finding that emerged from the literature is that those with schizophrenia are mostly immune to the effects of high-level illusory displays, but this effect is not consistent across all low-level illusions. The present review suggests that this resistance is due to the weakening of top–down perceptual mechanisms and may be relevant to the understanding of symptoms of visual distortion rather than hallucinations as previously thought

The neuroendocrine genome : neuropeptides and related signaling peptides

Neuropeptides are small proteinaceous substances which are produced, stored, and released through the regulated secretory route by neurons and act on neural substrates. They represent the most diverse group of signaling molecules in the nervous system. In mammals there are 200–300 neuropeptides known. These are encoded by just over 100 genes that express neuropeptide precursor proteins. These precursors share structural features that shuttle them through the regulated secretory pathways of cells and for controlled secretion. Several classes of peptides have been recognized that fit the definition of neuropeptides less strictly, including cytokines and neurotropins. An inventory of all currently known neuropeptides, their genes and receptors, as well as closely related signaling peptides in the nervous system, is provided here

A current view on contactin-4, -5, and -6: Implications in neurodevelopmental disorders.

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Contactins (Cntns) are a six-member subgroup of the immunoglobulin cell adhesion molecule superfamily (IgCAMs) with pronounced brain expression and function. Recent genetic studies of neuropsychiatric disorders have pinpointed contactin-4 (CNTN4), contactin-5 (CNTN5) and contactin-6 (CNTN6) as candidate genes in neurodevelopmental disorders, particularly in autism spectrum disorders (ASDs), but also in intellectual disability, schizophrenia (SCZ), attention-deficit hyperactivity disorder (ADHD), bipolar disorder (BD), alcohol use disorder (AUD) and anorexia nervosa (AN). This suggests that they have important functions during neurodevelopment. This suggestion is supported by data showing that neurite outgrowth, cell survival and neural circuit formation can be affected by disruption of these genes. Here, we review the current genetic data about their involvement in neuropsychiatric disorders and explore studies on how null mutations affect mouse behavior. Finally, we highlight to role of protein-protein interactions in the potential mechanism of action of Cntn4, -5 and -6 and emphasize that complexes with other membrane proteins may play a role in neuronal developmental functions.Authors of this review were supported by EU-AIMS (European Autism Interventions), which receives support from the Innovative Medicines Initiative Joint Undertaking under Grant agreement no.115300, there sources of which are composed of financial contributions from the European Union's Seventh Framework Programed Grant (P7/2007–2013), from the European Federation of Pharmaceutical Industries and Associations Companies' in-kind contributions, and from Autism Speaks. (K.T.E.K. and J.P.H.B.), by a Fellowship from JSPS (A.O.A. and A.Z)

ERK1/2 activation in rat ventral tegmental area by the mu-opioid agonist fentanyl: An in vitro study

Opioid receptors in the ventral tegmental area, predominantly the mu-opioid receptors, have been suggested to modulate reinforcement sensitivity for both opioid and non-opioid drugs of abuse. The present study was conducted to study signal transduction proteins, which may mediate the functioning of mu-opioid receptors in the neurons of the ventral tegmental area. Therefore, brain slices of the ventral tegmental area were exposed in vitro to the specific mu-opioid agonist fentanyl and immunohistochemically stained for four different activated proteins using phospho-specific antibodies. Fentanyl dose-dependently activated extracellular signal-regulated protein in brain slices of the ventral tegmental area. This activation was reversible with naloxone. Furthermore, naloxone itself also activated extracellular signal-regulated protein kinase. Under the present conditions fentanyl did not affect extracellular signal-regulated protein kinase 1 and 2, Stat and cyclic AMP-response element-binding protein activity. The direct activation of extracellular signal-regulated protein kinase in ventral tegmental area slices by the mu-opioid agonist fentanyl may suggest a role of extracellular signal-regulated protein kinase in reward processes. (C) 2003 IBRO. Published by Elsevier Science Ltd. All rights reserved

LOCALIZATION OF TRANSCRIPTS OF THE RELATED NUCLEAR ORPHAN RECEPTORS COUP-TF-I AND ARP-1 IN THE ADULT-MOUSE BRAIN

The chicken ovalbumin upstream promoter transcription factor, COUP-TF I, and the protein ARP-1 (COUP-TF II) are two highly homologous orphan receptors of the nuclear hormone receptor family. In this study we investigated their expression patterns in the adult nervous system of the mouse. In situ hybridizations were performed on brain sections with S-35-labeled cRNA probes derived from the 3'-non-coding regions of the mARP-1 and mCOUP-TF I mRNAs. Both COUP-TF I and ARP-1 were shown to be expressed in the adult brain and they displayed restricted and distinct expression patterns. COUP-TF I transcripts were predominantly found in the rostral and caudal parts of the adult mouse brain, whereas ARP-I transcripts prevaled in the middle part of the brain. High expression of COUP-TF I was detected in the olfactory nucleus, in neocortex layers I/II and V/VI, in the dentate gyrus and in areas CA1/CA3/CA4 of the hippocampus, and in the granular layer of the cerebellum. Only low amounts of COUP-TF I mRNA were detected in the ventral, the laterodorsal and in the interanteromedial thalamic nuclei. Small amounts of COUP-TF I transcripts were also found in the epithelial layer of the ventricle and in arachnoid membranes. High expression of ARP-I was detected in the reticular, the ventral lateral and the gelatinosus thalamic nuclei. Other hot spots of ARP-1 mRNA expression were the amygdaloid nucleus and the arachnoid membranes. Lower amounts of ARP-1 transcripts were found in the anterior and lateral hypothalamic areas, in the suprachiasmatic nucleus, and in the choroid plexus. Overlapping expression of COUP-TF I and ARP-1 mRNA was only found in the ventral lateral thalamic nucleus. These expression patterns do not coincide with a particular neuronal phenotype. The distinct distributions suggest different functional roles for each of the corresponding gene products in the mature nervous system