Genomic studies focusing on the contribution of common and rare genetic variants of schizophrenia and bipolar disorder support the view that substantial risk is conferred through molecular pathways involved in synaptic plasticity in the neurons of cortical and subcortical brain regions, including the hippocampus. Synaptic long-term potentiation (LTP) is central to associative learning and memory and depends on a pattern of gene expression in response to neuronal stimulation. Genes related to the induction of LTP have been associated with psychiatric genetic risk, but the specific cell types and timepoints responsible for the association are unknown.
View Article and Find Full Text PDFBackground: Genes that encode synaptic proteins or messenger RNA targets of the RNA-binding protein FMRP (fragile X messenger ribonucleoprotein) have been linked to schizophrenia and autism spectrum disorder (ASD) through the enrichment of genetic variants that confer risk for these disorders. FMRP binds many transcripts with synaptic functions and is thought to regulate their local translation, a process that enables rapid and compartmentalized protein synthesis required for development and plasticity.
Methods: We used summary statistics from large-scale genome-wide association studies of schizophrenia (74,776 cases, 101,023 controls) and ASD (18,381 cases, 27,969 controls) to test the hypothesis that the subset of synaptic genes that encode localized transcripts is more strongly associated with each disorder than nonlocalized transcripts.
Drivers of environmental change and policy processes are pushing the sub-Saharan African region to do more in the struggle against climate change as the region suffers most from climate change impact. To this end, this study investigates how the interaction effects of a sustainable financing model in energy use influence carbon emissions in Sub-Saharan African economies. It is based on the theory that energy consumption is determined by increased economic financing.
View Article and Find Full Text PDFAm J Med Genet B Neuropsychiatr Genet
June 2023
Large numbers of genetic loci have been identified that are known to contain common risk alleles for schizophrenia, but linking associated alleles to specific risk genes remains challenging. Given that most alleles that influence liability to schizophrenia are thought to do so by altered gene expression, intuitively, case-control differential gene expression studies should highlight genes with a higher probability of being associated with schizophrenia and could help identify the most likely causal genes within associated loci. Here, we test this hypothesis by comparing transcriptome analysis of the dorsolateral prefrontal cortex from 563 schizophrenia cases and 802 controls with genome-wide association study (GWAS) data from the third wave study of the Psychiatric Genomics Consortium.
View Article and Find Full Text PDFEarly-life adversity is associated with an increased risk of psychopathology, including mood disorders, later in life. Early-life stress affects several physiological systems, however, the exact mechanisms underlying pathological risk are not fully understood. This knowledge is crucial in developing appropriate therapeutic interventions.
View Article and Find Full Text PDFMyoclonus dystonia is a childhood-onset hyperkinetic movement disorder with a combined motor and psychiatric phenotype. It represents one of the few autosomal dominant inherited dystonic disorders and is caused by mutations in the ε-sarcoglycan (SGCE) gene. Work to date suggests that dystonia is caused by disruption of neuronal networks, principally basal ganglia-cerebello-thalamo-cortical circuits.
View Article and Find Full Text PDFLarge-scale genomic studies of schizophrenia implicate genes involved in the epigenetic regulation of transcription by histone methylation and genes encoding components of the synapse. However, the interactions between these pathways in conferring risk to psychiatric illness are unknown. Loss-of-function (LoF) mutations in the gene encoding histone methyltransferase, SETD1A, confer substantial risk to schizophrenia.
View Article and Find Full Text PDFBackground: Recent breakthroughs in psychiatric genetics have implicated biological pathways onto which genetic risk for psychiatric disorders converges. However, these studies do not reveal the developmental time point(s) at which these pathways are relevant.
Methods: We aimed to determine the relationship between psychiatric risk and developmental gene expression relating to discrete biological pathways.
There is increasing awareness of the role genetic risk variants have in mediating vulnerability to psychiatric disorders such as schizophrenia and autism. Many of these risk variants encode synaptic proteins, influencing biological pathways of the postsynaptic density and, ultimately, synaptic plasticity. Fragile-X mental retardation 1 () and cytoplasmic fragile-X mental retardation protein (FMRP)-interacting protein 1 () contain 2 such examples of highly penetrant risk variants and encode synaptic proteins with shared functional significance.
View Article and Find Full Text PDFThe mitochondrial protein, translocator protein (TSPO), is a widely used biomarker of neuroinflammation, but its non-selective cellular expression pattern implies roles beyond inflammatory processes. In the present study, we investigated whether neuronal activity modifies TSPO levels in the adult central nervous system. First, we used single-cell RNA sequencing to generate a cellular landscape of basal TSPO gene expression in the hippocampus of adult (12 weeks old) C57BL6/N mice, followed by confocal laser scanning microscopy to verify TSPO protein in neuronal and non-neuronal cell populations.
View Article and Find Full Text PDFMol Neuropsychiatry
June 2019
Alterations in synaptic signaling and plasticity occur during the refinement of neural circuits over the course of development and the adult processes of learning and memory. Synaptic plasticity requires the rearrangement of protein complexes in the postsynaptic density (PSD), trafficking of receptors and ion channels and the synthesis of new proteins. Activity-induced short Homer proteins, Homer1a and Ania-3, are recruited to active excitatory synapses, where they act as dominant negative regulators of constitutively expressed, longer Homer isoforms.
View Article and Find Full Text PDFSchizophrenia has been conceived as a disorder of brain connectivity, but it is unclear how this network phenotype is related to the underlying genetics. We used morphometric similarity analysis of MRI data as a marker of interareal cortical connectivity in three prior case-control studies of psychosis: in total, = 185 cases and = 227 controls. Psychosis was associated with globally reduced morphometric similarity in all three studies.
View Article and Find Full Text PDFCommon genetic variation contributes a substantial proportion of risk for both schizophrenia and bipolar disorder. Furthermore, there is evidence of significant, but not complete, overlap in genetic risk between the two disorders. It has been hypothesised that genetic variants conferring risk for these disorders do so by influencing brain development, leading to the later emergence of symptoms.
View Article and Find Full Text PDFMol Neuropsychiatry
December 2018
encodes the Ca1.2 L-type voltage-gated calcium channel. Generic variation in CACNA1C has been consistently identified as associated with risk for psychiatric disorders including schizophrenia, bipolar disorder, major depressive disorder and autism.
View Article and Find Full Text PDFJ Psychopharmacol
February 2018
Ketamine, principally an antagonist of N-methyl-ᴅ-aspartate receptors, induces schizophrenia-like symptoms in adult humans, warranting its use in the investigation of psychosis-related phenotypes in animal models. Genomic studies further implicate N-methyl-ᴅ-aspartate receptor-mediated processes in schizophrenia pathology, together with more broadly-defined synaptic plasticity and associative learning processes. Strong pathophysiological links have been demonstrated between fear learning and psychiatric disorders such as schizophrenia.
View Article and Find Full Text PDFGenes involved in synaptic plasticity, particularly genes encoding postsynaptic density proteins, have been recurrently linked to psychiatric disorders including schizophrenia and autism. Postsynaptic density Homer1 proteins contribute to synaptic plasticity through the competing actions of short and long isoforms. The activity-induced expression of short isoforms, and , is thought to be related to processes of learning and memory.
View Article and Find Full Text PDFLarge-scale genomic studies have made major progress in identifying genetic risk variants for schizophrenia. A key finding from these studies is that there is an increased burden of genomic copy number variants (CNVs) in schizophrenia cases compared with controls. The mechanism through which these CNVs confer risk for the symptoms of schizophrenia, however, remains unclear.
View Article and Find Full Text PDFJ Otolaryngol Head Neck Surg
February 2016
Background: Eustachian tube dysfunction (ETD) is a common medical issue, occurring in at least 1% of the adult population. Patients suffering from ET dysfunction typically present with complaints of hearing loss or sensation of pressure or plugged ear, which can lead to impaired quality of life. Over time ETD can result in conductive hearing loss or choleastatoma formation.
View Article and Find Full Text PDFMetabotropic glutamate-5 receptors (mGluR5), which physically and functionally interact with N-methyl-D-Aspartate (NMDA) receptors, likewise control cognitive processes and have been proposed as targets for novel classes of antipsychotic agent. Since social cognition is impaired in schizophrenia and disrupted by NMDA receptor antagonists like dizocilpine, we evaluated its potential modulation by mGluR5. Acute administration (0.
View Article and Find Full Text PDFAim of the study is to evaluate the effects of medical and surgical treatment in divers with paranasal sinus barotrauma (PSB) secondary to chronic rhinosinusitis (CRS). In this retrospective, cross-sectional, descriptive study 40 adult divers with CRS were included. Treatment of divers implied a 5-day course of a systemic steroid and a 6-week course of saline nasal irrigations and topical nasal steroid with mometasone in maximal dosage.
View Article and Find Full Text PDFBackground: Functional endoscopic sinus surgery (FESS) is now a well-established strategy for the treatment of chronic rhinosinusitis which has not responded to medical treatment. There is a wide variation in the practice of FESS by various surgeons within the UK and in other countries.
Objectives: To identify anatomic factors that may predispose to persistent or recurrent disease in patients undergoing revision FESS.
Over the last couple of decades, learning through simulation has become popularised for various reasons and is continuing to expand exponentially despite a lack of robust evidence that it actually improves outcomes for patients and learners. There has been a particular growth in the use of high-fidelity virtual reality simulators for surgical training as the technology has become more affordable. In the field of Otolaryngology, simulation appears to help teach simple procedural skills through to complex surgery of the temporal bone and paranasal sinuses.
View Article and Find Full Text PDFObjective: To report our experience of the management of patients with primary sinonasal malignant melanoma, and to review the relevant medical literature.
Method: Retrospective review examining treatment and outcomes.
Results: Twenty-four patients were treated between 1982 and 2007.