143 research outputs found
Functionally aberrant electrophysiological cortical connectivities in first episode medication-naive schizophrenics from three psychiatry centers
Functional dissociation between brain processes is widely hypothesized to
account for aberrations of thought and emotions in schizophrenic patients. The
typically small groups of analyzed schizophrenic patients yielded different
neurophysiological findings, probably because small patient groups are likely
to comprise different schizophrenia subtypes. We analyzed multichannel eyes-
closed resting EEG from three small groups of acutely ill, first episode
productive schizophrenic patients before start of medication (from three
centers: Bern N = 9; Osaka N = 9; Berlin N = 12) and their controls. Low
resolution brain electromagnetic tomography (LORETA) was used to compute
intracortical source model-based lagged functional connectivity not biased by
volume conduction effects between 19 cortical regions of interest (ROIs). The
connectivities were compared between controls and patients of each group.
Conjunction analysis determined six aberrant cortical functional
connectivities that were the same in the three patient groups. Four of these
six concerned the facilitating EEG alpha-1 frequency activity; they were
decreased in the patients. Another two of these six connectivities concerned
the inhibiting EEG delta frequency activity; they were increased in the
patients. The principal orientation of the six aberrant cortical functional
connectivities was sagittal; five of them involved both hemispheres. In sum,
activity in the posterior brain areas of preprocessing functions and the
anterior brain areas of evaluation and behavior control functions were
compromised by either decreased coupled activation or increased coupled
inhibition, common across schizophrenia subtypes in the three patient groups.
These results of the analyzed three independent groups of schizophrenics
support the concept of functional dissociation
Expression of ABC Efflux Transporters in Placenta from Women with Insulin-Managed Diabetes
Drug efflux transporters in the placenta can significantly influence the materno-fetal transfer of a diverse array of drugs and other xenobiotics. To determine if clinically important drug efflux transporter expression is altered in pregnancies complicated by gestational diabetes mellitus (GDM-I) or type 1 diabetes mellitus (T1DM-I), we compared the expression of multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 2 (MRP2) and the breast cancer resistance protein (BCRP) via western blotting and quantitative real-time polymerase chain reaction in samples obtained from insulin-managed diabetic pregnancies to healthy term-matched controls. At the level of mRNA, we found significantly increased expression of MDR1 in the GDM-I group compared to both the T1DM-I (p<0.01) and control groups (p<0.05). Significant changes in the placental protein expression of MDR1, MRP2, and BCRP were not detected (p>0.05). Interestingly, there was a significant, positive correlation observed between plasma hemoglobin A1c levels (a retrospective marker of glycemic control) and both BCRP protein expression (r = 0.45, p<0.05) and BCRP mRNA expression (r = 0.58, p<0.01) in the insulin-managed DM groups. Collectively, the data suggest that the expression of placental efflux transporters is not altered in pregnancies complicated by diabetes when hyperglycemia is managed; however, given the relationship between BCRP expression and plasma hemoglobin A1c levels it is plausible that their expression could change in poorly managed diabetes
Delta-9-tetrahydrocannabinol, neural oscillations above 20 Hz and induced acute psychosis
Rationale: An acute challenge with delta-9-tetrahydrocannabinol (THC) can induce psychotic symptoms including delusions. High electroencephalography (EEG) frequencies, above 20 Hz, have previously been implicated in psychosis and schizophrenia. Objectives: The objective of this study is to determine the effect of intravenous THC compared to placebo on high-frequency EEG. Methods: A double-blind cross-over study design was used. In the resting state, the high-beta to low-gamma magnitude (21–45 Hz) was investigated (n=13 pairs+4 THC only). Also, the event-related synchronisation (ERS) of motor-associated high gamma was studied using a self-paced button press task (n=15). Results: In the resting state, there was a significant condition × frequency interaction (p=0.00017), consisting of a shift towards higher frequencies under THC conditions (reduced high beta [21–27 Hz] and increased low gamma [27–45 Hz]). There was also a condition × frequency × location interaction (p=0.006), such that the reduction in 21–27-Hz magnitude tended to be more prominent in anterior regions, whilst posterior areas tended to show greater 27–45-Hz increases. This effect was correlated with positive symptoms, as assessed on the Positive and Negative Syndrome Scale (PANSS) (r=0.429, p=0.042). In the motor task, there was a main effect of THC to increase 65–130-Hz ERS (p=0.035) over contra-lateral sensorimotor areas, which was driven by increased magnitude in the higher, 85–130-Hz band (p=0.02) and not the 65–85-Hz band. Conclusions: The THC-induced shift to faster gamma oscillations may represent an over-activation of the cortex, possibly related to saliency misattribution in the delusional state
Influence of Maternal Dysmetabolic Conditions During Pregnancy on Cardiovascular Disease
Pathogenic factors associated with maternal hypercholesterolemia, obesity, and diabetic conditions during pregnancy influence fetal development and predispose offspring to cardiovascular disease. Animal models have established cause–effect relationships consistent with epidemiological findings in humans and have demonstrated, in principle, that interventions before or during pregnancy can reduce or prevent pathogenic in utero programming. However, little is known about the mechanisms by which maternal dysmetabolic conditions enhance disease susceptibility in offspring. Identification of these mechanisms is rendered more difficult by the fact that programming effects in offspring may be latent and may require conventional risk factors and inherited genetic co-factors to become clinically manifest. Given the increasing prevalence of maternal risk factors, which is expected to lead to a wave of cardiovascular disease in the coming decades, and the length of prospective studies on developmental programming in humans, greater-than-usual emphasis on experimental models and translational studies is necessary
Von Menschenbildern und Hirnmodellen
Haben die beeindruckenden Erkenntnisse der Hirnforschung das Menschenbild verändert, auf das sich die Psychiatrie beruft?
Ist die Befürchtung berechtigt, dass dadurch der Beziehungsaspekt und das Biographische in Psychiatrie und Psychotherapie an Bedeutung verlieren? Diesen Fragen geht Martha Koukkou im folgenden Text nach
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