Dimensional Traits of Schizotypy Associated With Glycine Receptor GLRA1 Polymorphism: An Exploratory Candidate-Gene Association Study

Proteomic profile of serum from patients with schizophrenia spectrum disorders

This article describes the most likely classes of proteins and molecular processes that specifically characterize schizophrenic spectrum disorders such as simple and paranoid schizophrenia, schizotypal disorder, and acute polymorphic psychotic disorder (APPD). The identification of patients' serum proteins was carried out using mass spectrometry. For patients with paranoid schizophrenia, the proteins responsible for translation and transcription are characteristic. A significant part of the proteins of patients with simple schizophrenia regulate the cell's main metabolic and transport processes. These are proteins of the receptor system, vesicular transport, and extracellular matrix, which mainly carry out catabolic processes. The proteins of patients with schizotypal disorder mostly coincided with the classes of other patients, apart from chaperone proteins, which were not found in other studied groups. These proteins are mainly involved in anabolic processes. The main classes of proteins found in patients with APPD are responsible for the metabolism of nucleic acids. Active apoptosis processes were also revealed in these patients. These results from our basic knowledge about the molecular mechanisms of the pathogenesis of these disorders.

[Clinical and psychological assessment of the variability of schizotypal personality disorder in children and adolescents]

OBJECTIVE

To analyze the variability of violations of cognitive and emotional-personal parameters in schizotypal disorder (STD) in children and adolescents according to the pathopsychological profile.

MATERIAL AND METHODS

47 patients with STD were examined, 21 of them with psychopathic variant (F21.4), 16 with neurotic (F21.3) and 10 with personality schizotypal disorder (F21.8) aged 9 to 16 years (37 boys and 10 girls). All patients were examined in detail by a psychiatrist and clinical psychologists. The method of integrative assessment of the pathopsychological profile was used, including the assessment of the presence and severity of impairments in cognitive functioning, emotional-personal and motivational-volitional spheres (the assessment was carried out according to detailed psychological reports). Mathematical processing of the obtained data was carried out.

RESULTS

Cluster analysis of clinical and psychological indicators showed that patients differ in the level of intellectual impairment, as well as in the characteristics of motivational-volitional and personal spheres. Three clusters are described, two of which included patients (10 and 31 patients) with individual variants of STD with a greater severity of various cognitive deficits, and parameters of the emotional and personal sphere, the last cluster included 6 patients with personality variants of STD. A separate largest cluster included all three analyzed variants of STD in approximately equal proportions, with a mildly pronounced intellectual decline and more noticeable changes (deficiency) in the emotional and personal sphere.

CONCLUSION

Thus, patients with STD differ in the severity and structure of deficient changes. At the same time, the nature and degree of involvement of a particular area in the overall picture of the pathopsychological profile is of great importance. Patients with STD differ in the severity and structure of deficient changes. The identified clusters differed in age, in the presence of patients of both sexes, and in various indicators of the pathopsychological profile. At the same time, the nature and degree of involvement of a particular area in the overall picture of the pathopsychological profile is important for diagnosis.

[History of the formation of views on schizotypal disorder in childhood]

The article reflects the stages of development of views on schizotypal disorder (STD) in adults and children from the prenosological period to the present. It is shown how, after the recognition by the majority of psychiatrists of the concept of early dementia proposed by E. Kraepelin, there is a gradual recognition of the single essence of schizophrenia for childhood and adulthood, but with different, specific clinical manifestations at different age periods. The study of variants of schizophrenia without a fatal outcome in dementia, which led to the isolation of sluggish schizophrenia, including in childhood, begins with the works of E. Bleuler. The differences in approaches to the study and interpretation of sluggish schizophrenia in Russian, European and American psychiatry, which led to the isolation of STEs in the framework of personality disorders, are described. Three main concepts that exist at the present stage of research are presented, in which STD is considered as an independent disease in the spectrum of schizophrenic disorders, as one of the types of personality deviations with a high degree of vulnerability for the development of schizophrenia, and as one of the forms of the disease.

Analysis of the brain transcriptome in lines of laying hens divergently selected for feather pecking

Background

Feather pecking (FP) in laying hens reduces animal welfare and leads to economic losses for the layer industry. FP is considered a heritable condition that is influenced by dysregulation of neurotransmitter homeostasis, the gut microbiome, and the immune system. To identify genes and biological pathways responsible for FP behavior we compared the brain transcriptomes of 48 hens divergently selected for FP. In addition, we tested if high feather peckers (HFP) and low feather peckers (LFP) respond differently to light since light has been shown to trigger FP behavior.

Results

Of approximately 48 million reads/sample an average of 98.4% were mapped to the chicken genome (GRCg6a). We found 13,070 expressed genes in the analyzed brains of which 423 showed differential expression between HFP and LFP. Genes of uncertain function and non-coding RNAs were overrepresented among those transcripts. Functional analyses revealed the involvement of cholinergic signaling, postsynaptic activity, membrane channels, and the immune system. After the light stimulus, 28 genes were found to be differentially expressed. These included an interaction cluster of core components of the circadian clock. However, differences in the response to light between HFP and LFP were not detectable.

Conclusions

Genes involved in cholinergic signaling, channel activity, synaptic transmission, and immune response were found to be involved in FP behavior. We propose a model in which the gut microbiota modulates the immune system, which in turn affects cholinergic signaling. This might have an influence on monoamine signaling with possible involvement of GABA or glutamate signaling.

Glycine Signaling in the Framework of Dopamine-Glutamate Interaction and Postsynaptic Density. Implications for Treatment-Resistant Schizophrenia

Treatment-resistant schizophrenia (TRS) or suboptimal response to antipsychotics affects almost 30% of schizophrenia (SCZ) patients, and it is a relevant clinical issue with significant impact on the functional outcome and on the global burden of disease. Among putative novel treatments, glycine-centered therapeutics (i.e. sarcosine, glycine itself, D-Serine, and bitopertin) have been proposed, based on a strong preclinical rationale with, however, mixed clinical results. Therefore, a better appraisal of glycine interaction with the other major players of SCZ pathophysiology and specifically in the framework of dopamine - glutamate interactions is warranted. New methodological approaches at cutting edge of technology and drug discovery have been applied to study the role of glycine in glutamate signaling, both at presynaptic and post-synaptic level and have been instrumental for unveiling the role of glycine in dopamine-glutamate interaction. Glycine is a non-essential amino acid that plays a critical role in both inhibitory and excitatory neurotransmission. In caudal areas of central nervous system (CNS), such as spinal cord and brainstem, glycine acts as a powerful inhibitory neurotransmitter through binding to its receptor, i.e. the Glycine Receptor (GlyR). However, glycine also works as a co-agonist of the N-Methyl-D-Aspartate receptor (NMDAR) in excitatory glutamatergic neurotransmission. Glycine concentration in the synaptic cleft is finely tuned by glycine transporters, i.e. GlyT1 and GlyT2, that regulate the neurotransmitter's reuptake, with the first considered a highly potential target for psychosis therapy. Reciprocal regulation of dopamine and glycine in forebrain, glycine modulation of glutamate, glycine signaling interaction with postsynaptic density proteins at glutamatergic synapse, and human genetics of glycinergic pathways in SCZ are tackled in order to highlight the exploitation of this neurotransmitters and related molecules in SCZ and TRS.