Cortical thickness and surface area correlates with cognitive dysfunction among first-episode psychosis patients.

BACKGROUND: In studies using magnetic resonance imaging (MRI), some have reported specific brain structure-function relationships among first-episode psychosis (FEP) patients, but findings are inconsistent. We aimed to localize the brain regions where cortical thickness (CTh) and surface area (cortical area; CA) relate to neurocognition, by performing an MRI on participants and measuring their neurocognitive performance using the Cambridge Neuropsychological Test Automated Battery (CANTAB), in order to investigate any significant differences between FEP patients and control subjects (CS). METHOD: Exploration of potential correlations between specific cognitive functions and brain structure was performed using CANTAB computer-based neurocognitive testing and a vertex-by-vertex whole-brain MRI analysis of 63 FEP patients and 30 CS. RESULTS: Significant correlations were found between cortical parameters in the frontal, temporal, cingular and occipital brain regions and performance in set-shifting, working memory manipulation, strategy usage and sustained attention tests. These correlations were significantly dissimilar between FEP patients and CS. CONCLUSIONS: Significant correlations between CTh and CA with neurocognitive performance were localized in brain areas known to be involved in cognition. The results also suggested a disrupted structure-function relationship in FEP patients compared with CS.

Wfs1-deficient animals have brain-region-specific changes of Na+, K+-ATPase activity and mRNA expression of α1 and ß1 subunits.

Mutations in the WFS1 gene, which encodes the endoplasmic reticulum (ER) glycoprotein, cause Wolfram syndrome, a disease characterized by juvenile-onset diabetes mellitus, optic atrophy, deafness, and different psychiatric abnormalities. Loss of neuronal cells and pancreatic ß-cells in Wolfram syndrome patients is probably related to the dysfunction of ER stress regulation, which leads to cell apoptosis. The present study shows that Wfs1-deficient mice have brain-region-specific changes in Na(+),K(+)-ATPase activity and in the expression of the α1 and ß1 subunits. We found a significant (1.6-fold) increase of Na-pump activity and ß1 subunit mRNA expression in mice lacking the Wfs1 gene in the temporal lobe compared with their wild-type littermates. By contrast, exposure of mice to the elevated plus maze (EPM) model of anxiety decreased Na-pump activity 1.3-fold in the midbrain and dorsal striatum and 2.0-fold in the ventral striatum of homozygous animals compared with the nonexposed group. Na-pump α1 -subunit mRNA was significantly decreased in the dorsal striatum and midbrain of Wfs1-deficient homozygous animals compared with wild-type littermates. In the temporal lobe, an increase in the activity of the Na-pump is probably related to increased anxiety established in Wfs1-deficient mice, whereas the blunted dopamine function in the forebrain of Wfs1-deficient mice may be associated with a decrease of Na-pump activity in the dorsal and ventral striatum and in the midbrain after exposure to the EPM.

Temperature dependence of the sodium pump is altered in the cerebral cortex of CCK2 receptor-deficient mice.

Previously we have shown that the temperature dependence of the sodium pump (Na(+),K(+)-ATPase) is altered under different neuropathological conditions. In this study we compared temperature dependence of the Na(+),K(+)-ATPase in the fronto-parietal cortex of CCK(2) receptor-deficient (homo- and heterozygous) and normal (wild-type) mice. The Arrhenius plot for Na(+),K(+)-ATPase from wild-type brain is non-linear with a breakpoint at 20.3 +/- 0.4 degrees C. In case of the brain cell membrane of CCK(2) receptor-deficient mice (homo- and heterozygous) the breakpoint on Arrhenius plot was detected at 26.0 +/- 1.1 degrees C and 25.4 +/- 0.4 degrees C, respectively. The shift of the breakpoint on the Arrhenius plot established in CCK(2) receptor-deficiency as well as in case of some other pathological conditions confirms that such kind of alteration in the Na(+),K(+)-ATPase temperature dependence is likely related to the homeostatic adjustment of altered function of the sodium pump.

Wfs1 gene deletion causes growth retardation in mice and interferes with the growth hormone pathway.

The aim of present study was to describe changes in gene expression in the temporal lobe of mice induced by deletion of the Wfs1 gene. Temporal lobes samples were analyzed using Affymetrix Mouse Genome 420 2 GeneChips and expression profiles were functionally annotated with GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 +/- 1.6 g) than their wild-type counterparts (31.0 +/- 0.6 g, P < 0.0001). This difference existed in 129S6 and C57B6 backgrounds. Interestingly, microarray analysis identified upregulation of growth hormone (GH) transcripts and functional analysis revealed activation of GH pathways. In line with microarray data, the level of IGF-1 in the plasma of Wfs1 mutant mice was significantly increased (P < 0.05). Thus, Wfs1 deletion induces growth retardation, whereas the GH pathway is activated. To test the interaction between the Wfs1 deletion and genomic background, mutant mice were backcrossed to two different genetic backgrounds. In line with previous studies, an interaction between a gene knockout and genetic background was found in gene expression profiles in the congenic region. However, genetic background did not alter the effect of the Wfs1 mutation on either body weight or GH pathway activation. Further studies are needed to describe biochemical and molecular changes of the growth hormone axis as well as in other hormones to clarify their role in growth retardation in the Wfs1 mutant mice.

Association analysis of IL20RA and IL20RB genes in psoriasis.

The interleukin-20-receptor I complex (IL-20-RI) is composed of two chains, IL20RA and IL20RB. Its ligands are the three members of the IL19 subfamily of cytokines, IL-19, IL-20 and IL-24. These cytokines are important in the manifestation of psoriatic lesions and, recently, an association of polymorphisms of IL20 with psoriasis has been described. In the present study we tested the hypotheses that genetic variations of the IL-20-RI influence susceptibility to psoriasis and investigated single nucleotide polymorphisms (SNPs) in the IL20RA and IL20RB genes in psoriasis patients (n=254) and healthy controls (n=224). We found no association of any of the investigated SNPs with the disease. Analysis of pairwise linkage disequilibrium (LD) across studied markers revealed a strong level of LD between SNPs within the IL20RA gene and SNPs within the IL20RB gene, and, for both genes six common haplotypes were identified with an estimated frequency >or=1%. Haplotype analyses suggested that the IL20RA haplotype CCG (rs1184860, rs1167846, rs1167849) is significantly associated with psoriasis (OR 3.14, 95% CI 1.61-6.14), whereas the TTG haplotype had a protective effect (OR 0.20, 95% CI 0.07-0.55). The risk haplotype defining SNPs 1167846 and 1184860 were found to modify paired box 5 and homeobox A9 sites, respectively, two transcription factors related to the differentiation of immune cells. Further studies are needed to confirm the genetic association and to investigate the functional relevance of IL20RA haplotypes in psoriasis.

Gene expression study of IL10 family genes in vitiligo skin biopsies, peripheral blood mononuclear cells and sera.

BACKGROUND: Vitiligo is a pigmentation disorder, the cause of which is complex and not yet fully understood. There is a significant change of epidermal cytokines in involved skin of patients with vitiligo compared with uninvolved skin and skin of healthy controls, thus suggesting a possible involvement of cytokines in the pathogenesis of vitiligo. OBJECTIVES: To evaluate potential roles of IL10 family cytokines (IL10, IL19, IL20, IL22 and IL24) in vitiligo. Along with the selected cytokines, we investigated subunits of the receptors (IL10RA, IL10RB, IL20RA and IL22RA1) which are involved in the signalling pathway of the cytokines. METHODS: Quantitative real-time polymerase chain reaction was used to detect mRNA expression levels in samples extracted from skin biopsies and peripheral blood mononuclear cells and an enzyme-linked immunosorbent assay was used to measure protein concentrations in serum from patients with vitiligo and healthy controls. RESULTS: IL22 is significantly associated with vitiligo, especially with the active stage of vitiligo, as shown by results of mRNA expression and supported by results of protein level in sera. IL22 may provoke inflammation which leads to destruction of melanocytes. CONCLUSIONS: The actual role of IL22 during pathogenesis of vitiligo remains to be better characterized. Signal transductions of other investigated cytokines seem to be regulated on the expression level of their receptor complex subunits.

Mild stress induces brain region-specific alterations of selective ER stress markers' mRNA expression in Wfs1-deficient mice.

In this work, the effect of mild stress (elevated plus maze test, EPM) on the expression of endoplasmic reticulum (ER) stress markers in different brain areas of wild type (WT) and Wfs1-deficient (Wfs1KO) mice was investigated. The following ER stress markers were studied: activating transcription factor 6α (Atf6α), protein kinase-like ER kinase (Perk), X-box binding protein 1 (Xbp1) and its spliced form (Xbp1s), 78-kilodalton glucose regulated protein (Grp78), 94-kilodalton glucose regulated protein (Grp94), C/EBP homologous protein (Chop). Wfs1KO and WT mice, not exposed to EPM, had similar patterns of ER stress markers in the studied brain areas. The exploratory activity of Wfs1KO mice in the EPM was inhibited compared to WT mice, probably reflecting increased anxiety in genetically modified mice. In response to the EPM, activation of inositol-requiring transmembrane kinase and endonuclease 1α (Ire1α) ER stress pathway was seen in both genotypes, but in different brain areas. Such a brain region-specific Ire1α activation was linked with dominant behavioural trends in these mice as more anxious, neophobic Wfs1KO mice had increased ER stress markers expression in the temporal lobe, the brain region related to anxiety, and more curious WT mice had ER stress markers increased in the ventral striatum which is related to the exploratory drive. The molecular mechanism triggering respective changes in ER stress markers in these brain regions is likely related to altered levels of monoamine neurotransmitters (serotonin, dopamine) in Wfs1KO mice.

Interpretation of knockout experiments: the congenic footprint.

In gene targeting experiments, the importance of genetic background is now widely appreciated, and knockout alleles are routinely backcrossed onto a standard inbred background. This produces a congenic strain with a substantial segment of embryonic stem (ES)-cell-derived chromosome still flanking the knockout allele, a phenomenon often neglected in knockout studies. In cholecystokynin 2 (Cckbr) knockout mice backcrossed with C57BL/6, we have found a clear 'congenic footprint' of expression differences in at least 10 genes across 40 Mb sequence flanking the Cckbr locus, each of which is potentially responsible for aspects of the 'knockout' phenotype. The expression differences are overwhelmingly in the knockout-low direction, which may point to a general phenomenon of background dependence. This finding emphasizes the need for caution in using gene knockouts to attribute phenotypic effects to genes. This is especially the case when the gene is of unknown function or the phenotype is unexpected, and is a particular concern for large-scale knockout and phenotypic screening programmes. However, the impact of genetic background should not be simply viewed as a potential confound, but as a unique opportunity to study the broader responses of a system to a specific (genetic) perturbation.

Inflammatory, cardio-metabolic and diabetic profiling of chronic schizophrenia.

BACKGROUND: There is a growing interest in low-grade inflammatory and metabolic alterations in patients with chronic schizophrenia (SCH). METHODS: Inflammatory (tumor-necrosis factor-α [TNF-α], interferon-γ [IFN-γ], interleukins [IL-1α, IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10], monocyte chemo-attractant protein-1 [MCP-1]) and growth factors (vascular endothelial growth factor [VEGF], epidermal growth factor [EGF]) were measured in blood serum samples of 105 SCH patients and 148 control subjects (CS). Simultaneously the clinical biomarkers (C-reactive protein [CRP], triglycerides [TG], low-density lipoprotein [LDL-c] and high-density lipoprotein [HDL-c] cholesterol, glycated hemoglobin [HbA1c]) were measured, and body mass index (BMI) was calculated for patients. RESULTS: Several cyto-/chemokines (IFN-γ, MCP-1, IL-2, IL-6, IL-8 and IL-10) were significantly (P<0.0000001) elevated in SCH patients compared to CS. Odds ratios, obtained from logistic regression analyses, were significantly elevated for IL-2, IL-6, IL-10, INF-γ, and decreased for TNF-α in SCH group. Among the patients, higher IL-2, IL-6, INF-γ and lower MCP-1 levels as well as male gender were together significant (P<0.000001) predictors of higher HbA1c levels, and TG/HDL-c parameter was associated with ratios of INF-γ/IL-10 (P=0.004), and INF-γ/IL-4 (P=0.049), HbA1c (P=0.005), INF-γ (P=0.009), as well as LDL-c (P=0.02) levels. CONCLUSIONS: IL-2, IL-6, IL-10 and IFN-γ were the most significant SCH-related markers among the measured cytokines in our patient group. Furthermore, significant associations between pro-/anti-inflammatory imbalance and HbA1c as well as cardio-metabolic risk marker (TG/HDL-c) were observed, indicating higher risks of diabetes and cardiovascular diseases among SCH patients.

High-performance liquid chromatography method with radiochemical detection for measurement of nitric oxide synthase, arginase, and arginine decarboxylase activities.

Nitric oxide has been shown to be involved in numerous biological processes, and many studies have aimed to measure nitric oxide synthase (NOS) activity. Recently, it has been demonstrated that arginase and arginine decarboxylase (ADC), two enzymes that also employ arginine as a substrate, may regulate NOS activity. We aimed to develop a HPLC-based method to measure simultaneously the products of these three enzymes. Traditionally, the separation of amino acids and related compounds with HPLC has been carried out with precolumn derivatization and reverse phase chromatography. We describe here a simple and fast HPLC method with radiochemical detection to separate radiolabeled L-arginine, L-citrulline, L-ornithine, and agmatine. 3H-labeled L-arginine, L-citrulline, agmatine, and 14C-labeled L-citrulline were used as standards. These compounds were separated in the normal phase column (Allure Acidix 250 x 4.6 mm i.d.) under isocratic conditions in less than 20 min with good sensitivity. Using the current method, we have shown the formation of L-citrulline and L-ornithine in vitro using brain tissue homogenate of rats and that of agmatine by Escherichia coli ADC.

Long-term individual housing in C57BL/6J and DBA/2 mice: assessment of behavioral consequences.

The aim of the present study was to investigate the effects of individual housing on mouse behavior. The male mice of the C57BL/6J and DBA/2 strains were separated at the age of 4 weeks and kept in individual housing for 7 weeks until behavioral testing began. Their behavior was compared to the group-housed mice in a battery of tests during the following 7 weeks. The single-housed mice were hyperactive and displayed reduced habituation in the tests assessing activity and exploration. Reduced anxiety was established in the elevated plus-maze, but an opposite effect was observed in the dark-light (DL) and hyponeophagia tests. Immobility in the forced swimming test was reduced by social isolation. The DBA mice displayed higher anxiety-like behavior than the B6 mice in the plus-maze and DL exploration test, but hyponeophagia was reduced in the DBA mice. Moreover, all effects of individual housing on the exploratory and emotional behavior were more evident in the DBA than in the B6 mice. Novel object recognition and fear conditioning (FC) were significantly impaired in the single-housed mice, whereas water-maze (WM) learning was not affected. Marked strain differences were established in all three learning tests. The B6 mice performed better in the object recognition and FC tasks. Initial spatial learning in the WM was faster and memory retention slightly enhanced in the B6 mice. The DBA mice displayed lower preference to the new and enhanced preference to the old platform location than the B6 mice after reversal learning in the WM. We conclude that individual housing has strong strain- and test-specific effects on emotional behavior and impairs memory in certain tasks.

CCK in animal and human research on anxiety.

Much data has accumulated over the past decade supporting the hypothesis that CCK plays a role in the neurobiology of anxiety and panic attacks. These data originated from animal studies and human studies that were initiated independently, but the conclusions are remarkably consistent. In this review, Jacques Bradwejn and colleagues examine the evidence for a role of CCK in anxiety and panic attacks, and highlight the consistencies between animal and human studies.

Cholecystokinin-induced anxiety: how is it reflected in studies on exploratory behaviour?

Central cholecystokinin (CCK)-ergic neurotransmission has been implicated in the genesis of negative emotions. Most animal studies on the neurochemical background of CCK-induced anxiety have, up to date, exploited exploratory activity paradigms. The interaction of CCK with GABAergic inhibitory neurotransmission, mediated probably through CCK-B receptors, could be the neurochemical substrate for anxious type of exploratory behaviour. However, the CCK-A and CCK-B receptor-mediated interactions of this neuropeptide with mesencephalic dopaminergic regulation of motivation for locomotor activity have the potential to interfere with the behavioural outcome from routine exploratory activity tests. Systemic treatment with CCK receptor antagonists is likely to influence both GABA- and dopamine-linked CCK-ergic neurotransmission, and therefore their effects in exploratory activity tests should be interpreted with caution.

Behavioral alterations induced by repeated testing in C57BL/6J and 129S2/Sv mice: implications for phenotyping screens.

The C57BL/6JOlaHsd and 129S2/SvHsd mice were tested in a battery designed for behavioral phenotyping of genetically modified mice. The study was performed in order to reveal the effect of training history on the behavior by comparison with the experimentally naive mice in the same tests. Significant strain differences were obtained in all experiments. Previous handling and testing reduced exploratory activity and emotionality significantly in the mice. The coordination ability was better and nociceptive sensitivity was increased in the trained mice. The contextual fear was reduced whereas the cued fear was enhanced in the experienced mice. The training history did not alter initial learning in the water maze. However, after reversal learning the naive mice displayed significant preference for both old and new platform locations, whereas the battery animals did not exhibit preference to the old location. The experienced mice appeared to be less active in the forced swimming test and exhibited decreased conditioned taste aversion. The influence of test history was strain-dependent in certain cases. Therefore, the experience has substantial consequences on the behavior, mainly by reducing exploratory activity, and the previous experience of the animals has always to be considered in the analysis of genetically modified mice.

A screen for genes induced in the amygdaloid area during cat odor exposure.

The aim of a present study was to identify the genes activated or inactivated in the amygdaloid area after the exposure to cat odor. Cat odor exposure was used to induce the ethologically relevant anxiety reaction in male rats. Differential expression of genes was analyzed using the cDNA Representational Difference Analysis (cDNA RDA). Differentially expressed mRNAs were identified by sequencing combined with database search and subsequently verified by dot blot analysis. Exposure of rats to cat odor induced avoidance of odor stimulus and suppressed the exploratory activity of animals. We found that during the cat odor exposure several genes with various functions were activated in the amygdaloid area of rat. Moreover, reverse subtraction resulted in a different set of genes that are inactivated during anxiety response. These genes can be classified according to their function as the neurotransmission related, enzymes, cell cycle regulating proteins and transcription factors. We found that during anxiety response the genes participating directly or indirectly in the synthesis of neurotransmitters (carboxypeptidase E, tyrosine 3-monooxygenase/tryptophan 5-mono-oxygenase activation protein, wolframin) were up regulated. Moreover, a number of genes involved in the signal transduction (Rho GTPase, neurochondrin, Ca/calmodulin-dependent protein kinase) were also activated. Additionally, reverse subtraction in control animals identified several up regulated genes having the antagonistic action to these genes (nischarin, Rab geranylgeranyl transferase). In conclusion, we were able to define the possible pathways linked to the regulation of anxiety response.

The effect of cholecystokinin tetrapeptide on respiratory resistance in healthy volunteers.

The effects of cholecystokinin tetrapeptide (CCK-4) on respiratory resistance were studied in 14 healthy volunteers by the registration of slow vital capacity and flow volume loop during forced respiration test. The administration of CCK-4 (50 micrograms) was performed in a double-blind and placebo-controlled design. Injections of CCK-4 induced prominent and time-limited paniclike symptoms in all healthy volunteers. Four volunteers (29%) experienced a panic attack. Subjective dyspnea was experienced by the majority of subjects at the peak of CCK-4 effect and seemed related to a diminution in vital capacity parameters; however, the forced respiration test did not reveal bronchoconstriction after CCK-4 challenge. Administration of CCK-4 also induced a short-lasting increase in heart rate and skin blood flow. This study suggests that dyspnea induced by CCK-4 is not related to changes in respiratory resistance.

Evidence for potentiation by CCK antagonists of the effect of cholecystokinin octapeptide in the elevated plus-maze.

Systemic treatment with cholecystokinin octapeptide (CCK-8, 2.5-10 micrograms/kg, s.c.), a non-selective CCK agonist, decreased the exploratory activity of mice in an elevated plus-maze. At higher doses (5-10 micrograms/kg) CCK-8 reduced the frequency of rearing, but only 10 micrograms/kg of CCK-8 significantly inhibited the number of line crossings in the open-field test. A preferential CCKB antagonist L-365,260 (1 and 100 micrograms/kg, i.p.) and a non-selective CCK antagonist proglumide (0.1-1 microgram/kg, i.p.) potentiated the anti-exploratory effect of CCK-8 (2.5 micrograms/kg). Devazepide, a preferential CCKA antagonist, only at a high dose (100 micrograms/kg) tended to increase the action of CCK-8 in the plus-maze. However, the concomitant treatment of CCK-8 with L-365,260 and proglumide, differently from devazepide, also suppressed the locomotor activity in the open-field test. Therefore, it is likely that the potentiation by CCK antagonists of the anti-exploratory effect of CCK-8 is related to the suppression of motor activity. This peculiar interaction between CCK-8 and CCK antagonists could be explained in the light of the opposite role of CCKA and CCKB receptors in the regulation of motor activity in mice.

Ondansetron, an antagonist of 5-HT3 receptors, antagonizes the anti-exploratory effect of caerulein, an agonist of CCK receptors, in the elevated plus-maze.

Systemic treatment with caerulein (0.25-5 micrograms/kg SC), non-selective agonist of cholecystokinin (CCK) receptors, dose-dependently suppressed the exploratory behaviour of rats in an elevated plus-maze without producing remarkable changes in the locomotor activity of animals in an open field test. Ondansetron, a selective antagonist of 5-HT3 receptors, increased the number of open arm entries in the plus-maze test only at a dose 10 micrograms/kg. The other doses of ondansetron (0.1, 1 and 100 micrograms/kg IP) did not significantly change either the locomotor activity or the exploratory behaviour of rats. Pretreatment of rats with ondansetron (at 10 micrograms/kg, but not at 0.1, 1 or 100 micrograms/kg) completely reversed the anti-exploratory effect of caerulein (5 micrograms/kg). The concomitant treatment with caerulein and ondansetron did not cause any major change in the locomotor activity of animals in open field. Consequently, we propose that 5-HT-ergic mechanisms are involved not only in the regulation of CCK release in the cerebral cortex and nucleus accumbens, but also in the modulation of the anti-exploratory effect of caerulein, a CCK agonist, in the elevated plus-maze.

Differential involvement of CCK-A and CCK-B receptors in the regulation of locomotor activity in the mouse.

The influence of the CCK-A antagonist devazepide and the CCK-B/gastrin antagonist L-365,260 on the locomotor activity of mice was studied. Devazepide and L-365,260 had opposite effects on spontaneous locomotor activity, and on caerulein- and apomorphine-induced hypomotility in the mouse. Devazepide in high doses (0.1-1 mg/kg IP) reduced spontaneous motor activity, whereas L-365,260 at a high dose (1 mg/kg IP) increased the activity of mice. Devazepide (0.1-10 micrograms/kg) moderately antagonized the sedative effect of apomorphine (0.1 mg/kg SC) and caerulein (25 micrograms/kg SC), whereas L-365,260 (1-10 micrograms/kg) significantly potentiated the actions of dopamine and CCK agonists. Concomitant administration of caerulein (15 micrograms/kg SC) and apomorphine (0.1 mg/kg SC) caused an almost complete loss of locomotor activity in the mouse. Devazepide and L-365,260 (0.1-10 micrograms/kg) were completely ineffective against caerulein-induced potentiation of apomorphine hypomotility. Devazepide in high doses (0.1-1 mg/kg), reducing the spontaneous motor activity of mice, counteracted the motor excitation induced by d-amphetamine (5 mg/kg IP). The CCK agonist caerulein (100 micrograms/kg SC) had a similar antiamphetamine effect. Devazepide (1-100 micrograms/kg) and L-365,260 (1 micrograms/kg) reversed completely the antiamphetamine effect of caerulein. The results of present study reflect apparently distinct role of CCK-A and CCK-B receptors in the regulation of motor activity. The opposite effect of devazepide and L-365,260 on caerulein- and apomorphine-induced hypolocomotion is probably related to the antagonistic role of CCK-A and CCK-B receptor subtypes in the regulation of mesencephalic dopaminergic neurons. The antiamphetamine effect of caerulein is possibly linked to the stimulation of CCK-A receptors in the mouse brain, whereas the blockade of both subtypes of the CCK-8 receptor is involved in the antiamphetamine effect of devazepide.