Biomedical subjects

Csongor Cimmer

Publications and source records attributed to Csongor Cimmer.

4 recordsLinked to original sources

PubMed2006

Abnormal neurological signs, visual contrast sensitivity, and the deficit syndrome of schizophrenia.

This study was designed to investigate the relationship between abnormal neurological signs, visual contrast sensitivity, and the deficit syndrome of schizophrenia. Visual contrast sensitivity for counterphase-modulated low spatial frequency gratings was measured in 32 non-deficit and 12 deficit schizophrenia patients and 20 healthy controls subjects. Abnormal neurological signs were evaluated with the Neurological Evaluation Scale (NES). Compared with the controls, patients with schizophrenia displayed impaired visual contrast sensitivity, which was associated with sensory integration deficits, as measured with the NES. The deficit syndrome was predicted by negative symptoms and sensory integration deficits. These results suggest that early-stage perceptual dysfunctions, which may reflect the abnormality of precortical magnocellular visual pathways, are related to a specific group of abnormal neurological signs.

Adult↗

PubMed2006

Correlations between clinical symptoms, working memory functions and structural brain abnormalities in men with schizophrenia.

Thirteen male patients with schizophrenia and thirteen male normal control subjects were compared by magnetic resonance imaging (MRI) on volumes of the straight gyrus (SG), anterior cingulate gyrus, middle frontal gyrus, hippocampus, third ventricle, cavum septi pellucidi, total brain volume and intracranial volume. In addition, neuropsychological tasks were used to measure working memory and executive functions. Healthy volunteers and schizophrenic patients showed no significant differences in mean values for volumes of regions of interests. In the case of the SG, we found a significant difference in laterality: the tendency toward left dominance in healthy volunteers changed to significant right dominance in patients. The schizophrenic patients showed lower performance in working memory tasks, and strongly significant group differences were observed in measures of neurological signs assessed by the Neurological Evaluation Scale (NES). Negative symptoms correlated with the level of spatial working memory and executive functions. Negative symptoms also correlated with the volume of the right hippocampus, while the rate of anhedonia negatively correlated with the relative volume of the left SG.

Adult↗

PubMed2005

Habit learning and the genetics of the dopamine D3 receptor: evidence from patients with schizophrenia and healthy controls.

In this study, the authors investigated the relationship between the Ser9Gly (SG) polymorphism of the dopamine D3 receptor (DRD3) and striatal habit learning in healthy controls and patients with schizophrenia. Participants were given the weather prediction task, during which probabilistic cue-response associations were learned for tarot cards and weather outcomes (rain or sunshine). In both healthy controls and patients with schizophrenia, participants with Ser9Ser (SS) genotype did not learn during the early phase of the task (1-50 trials), whereas participants with SG genotype did so. During the late phase of the task (51-100 trials), both participants with SS and SG genotype exhibited significant learning. Learning rate was normal in patients with schizophrenia. These results suggest that the DRD3 variant containing glycine is associated with more efficient striatal habit learning in healthy controls and patients with schizophrenia.

Adult↗

PubMed2005

Over-expression of dopamine D2 receptor and inwardly rectifying potassium channel genes in drug-naive schizophrenic peripheral blood lymphocytes as potential diagnostic markers.

Schizophrenia is one of the most common neuropsychiatric disorders affecting nearly 1% of the human population. Current diagnosis of schizophrenia is based on complex clinical symptoms. The use of easily detectable peripheral molecular markers could substantially help the diagnosis of psychiatric disorders. Recent studies showed that peripheral blood lymphocytes (PBL) express subtypes of D1 and D2 subclasses of dopamine receptors. Recently, dopamine receptor D3 (DRD3) was found to be over-expressed in schizophrenic PBL and proposed to be a diagnostic and follow-up marker for schizophrenia. In this study we screened PBL of 13 drug-naive/drug-free schizophrenic patients to identify additional markers of schizophrenia. One of the benefits of our study is the use of blood samples of non-medicated, drug-naive patients. This excludes the possibility that changes detected in gene expression levels might be attributed to the medication rather than to the disorder itself. Among others, genes for dopamine receptor D2 (DRD2) and the inwardly rectifying potassium channel (Kir2.3) were found to be over-expressed in microarray analysis. Increased mRNA levels were confirmed by quantitative real-time PCR (QRT-PCR) using the SybrGreen method and dual labeled TaqMan probes. The use of both molecular markers allows a more rapid and precise prediction of schizophrenia and might help find the optimal medication for schizophrenic patients.

Adult↗