Insertion/Deletion Polymorphism of the Serotonin Transporter Gene and Neuroticism as a Temperament Trait in Affective Patients and Healthy Individuals

Some studies associate the insertion/deletion polymorphism of the serotonin transporter (5-HTT) gene with anxiety-related personality traits in mentally healthy people, the short (s) allele being associated with a higher neuroticism score. The 5-HTT genotype and neuroticism score were established for 114 affective patients, 87 healthy relatives of endogenous psychosis patients, and for 156 mentally healthy people without familial psychiatric history. The effects of sex and age on the association between the two parameters was studied. Neuroticism proved to be not associated with the 5-HTT genotype.     

Microstructural abnormalities of the corpus callosum and fasciculus uncinatus and auditory information processing in patients with juvenile paroxysmal schizophrenia

One approach to the problem of determining the mechanisms coupling the structure and functions of the brain is studies in clinical populations aimed at assessing the presence or absence of congruence of anatomical/ morphological and functional abnormalities. Magnetic resonance imaging (MRI), including structural MRI and diffusion tensor imaging with tractography, as well as the recording of auditory event-related potentials (ERPs) in the standard two-tone oddball paradigm and the sensory gating paradigm, was conducted in 26 male patients with paroxysmal juvenile schizophrenia and 26 mentally healthy men with no family history of mental illness. MRI abnormalities have been found in the genu of the corpus callosum and fasciculus uncinatus of the left hemisphere of the patients. Reduction of the fractional anisotropy in the genu of the corpus callosum was correlated with P300 reduction in the right temporal region.     

Some electrophysiological and hemodynamic characteristics of auditory selective attention in norm and schizophrenia

Six patients in the state of remission after the first episode ofjuvenile schizophrenia and seven sex- and age-matched mentally healthy subjects were examined by fMRI and ERP methods. The auditory oddball paradigm was applied. Differences in P300 parameters didn't reach the level of significance, however, a significantly higher hemodynamic response to target stimuli was found in patients bilaterally in the supramarginal gyrus and in the right medial frontal gyrus, which points to pathology of these brain areas in supporting of auditory selective attention.     

Intergeneric asymmetric hybrids between Nicotiana plumbaginifolia and Atropa belladonna obtained by “gamma-fusion”

Summary Asymmetric nuclear hybrids have been obtained by fusion of cells from a nitrate-reductase deficient mutant of Nicotiana plumbaginifolia (cnx20) and gamma irradiated protoplasts of Atropa belladonna (irradiation doses tested were 10, 30, 50 and 100 krad). The hybrid formation frequency following selection for genotypic complementation in the NR function was in the range of 0.7%–3.7%. Cytogenetic studies demonstrated that all hybrid plants tested possessed multiple (generally tetra- or hexaploid) sets of N. plumbaginifolia (n = 10) chromosomes along with 6–29 Atropa chromosomes (n = 36), some of which were greatly deleted. Besides the cnxA gene (the selection marker), additional material of the irradiated partner was expressed in some of the lines, as shown by analyses of multiple molecular forms of enzymes. Surprisingly, rDNA genes of both parental species were present and amplified in the majority of the hybrids. Whenever studied, the chloroplast DNA in the hybrids was derived from the Nicotiana parent. Regenerants from some lines flowered and were partially fertile. It is concluded that irradiation of cells of the donor parent before fusion can be used to produce highly asymmetric nuclear hybrid plants, although within the dose range tested, the treatment determined the direction of the elimination but not the degree of elimination of the irradiated genome.Abbreviations and Definitions Cp chloroplast - CsCl/EtBr cesiumchloride/ethidiumbromide - EDTA ethyldiamine tris acetate - NR nitrate reductase - SDS sodiumdodecylsulphate - Gamma-fusion is a conventional abbreviation for fusion experiments in which one fusion partner (the donor) is inactivated by sub- or lethal doses of irradiation before fusion with the other (the recipient) partner.     

Polymorphism C366G of gene <Emphasis Type="Italic">GRIN2B</Emphasis> and verbal episodic memory: No association with schizophrenia

The present study searched for associations between gene GRIN2B (glutamate receptor, ionotropic, N-methyl-D-aspartate, subunit 2B) and component processes of verbal episodic memory in schizophrenic patients. The Rey Auditory Verbal Learning Test (RAVLT) as a part of a large neuropsychological battery was administered to 302 patients with schizophrenic spectrum disorders (sample PI). Also, 285 patients (sample P2) and 243 healthy controls (sample C2) performed the “10 words” test that measures short-term memory. The GRIN2B rs7301328 (C366G) polymorphism was genotyped for each subject. There were no associations between the polymorphism and any measure of the RAVLT either in the whole PI sample or in a subsample of patients with a severe cognitive deficit. The GRIN2B influenced immediate recall and proactive interference in the “10 words” test in the control group: homozygotes CC recalled fewer words and showed a lower effect of proactive interference than carriers of other genotypes. The results suggest that the C366G polymorphism could influence verbal episodic memory in the general population, but this influence is absent in schizophrenic patients.     

Correlations between some structural and functional brain parameters in subjects with high risk of schizophrenia

The study was aimed to the analysis of correlations between anatomic brain parameters and characteristics of neurophysiological and metabolic supportive mechanisms of cognitive functions in the patients with ultra-high risk of schizophrenia. The study comprised 30 young male patients and 30 age- and sexmatched mentally healthy subjects. We used the methods of diffusion-weighted tomography, single voxel proton MR spectroscopy, and oddball ERP recording. The statistically significant intergroup differences in the structural connectivity were confirmed in the anterior thalamic radiation of the left hemisphere. The diffusion abnormalities in this area were correlated with P300 latencies and the level of γ-aminobutyric acid (GABA).     

<Superscript>1</Superscript>H-MRS and MEGA-PRESS pulse sequence in the study of balance of inhibitory and excitatory neurotransmitters in the human brain of ultra-high risk of schizophrenia patients

The MEGA-PRESS pulse sequence was used for determination of overlapping signals in the ¹H-MRS spectra of the human brain. For the first time, the balance of GABA glutamate/glutamine concentrations was estimated quantitatively in the human brain of patients with ultra-high risk of schizophrenia. It was found that GABA concentration and GABA/GLX ratios were significantly reduced in the left frontal lobe of UHR subjects.     

Polymorphism in the human serotonin transporter gene in endogenous psychoses

Associations of the VNTR-17 and 5-HTTLPR polymorphisms of the serotonin transporter gene with affective disorders, including depression, have been found. These polymorphisms were analyzed in two groups of Russian probands: patients with endogenous psychoses and control individuals without mental disorders (423 and 277 persons, respectively). No associations were found between VNTR-17 genotypes or alleles and the diseases. However, the frequency of 10/10 (VNTR-17) homozygotes increased with age in both patients and healthy persons. The results of the analysis of the 5-HTTLPR polymorphism suggest an association of the short (s) allele of the 5-HTTLPR polymorphism with schizophrenia and schizoaffective psychoses, but not with affective disorders.     

TaqIB allele polymorphism of the dopamine receptor D2 gene in patients with endogenous psychoses

The genotype at theTaqIB locus of the dopamine receptor D2 (DRD2) gene was established by PCR in 113 healthy donors and 340 patients with endogenous psychoses. The allele and genotype frequencies in patients with affective psychoses significantly differed from those in controls and in patients with schizophrenia. The proportion of B2/B2 homozygotes decreased with increasing contribution of the affective component to the clinical manifestation of schizo-affective and affective disorders. TheTaqIB polymorphism was assumed to play a role in mood aberrations in patients with mental disorders.