1H- und 31P-Magnetresonanzspektroskopie bei Ultra-High-Risk-Patienten für psychotische Störungen: Alterationen von glutamaterger Neurotransmission, Membranlipid- und Energiemetabolismus

Bei fast allen Individuen, welche später eine psychotische Störung entwickeln, finden sich bereits Jahre vor dem eigentlichen Ausbruch abgeschwächte Krankheitssymptome sowie meist eine deutliche Verschlechterung des allgemeinen Funktionsniveaus. Die Definition eines Hochrisikostadiums bezüglich der Entwicklung einer psychotischen Erkrankung (ultra-high-risk, UHR) zielte darauf ab, Individuen mit erkennbarer Prodromalsymptomatik möglichst frühzeitig zu identifizieren, im Verlauf zu beobachten und ggf. einer geeigneten Präventions- oder Therapiemaßnahme zuzuführen. Mit Hilfe der Magnetresonanzspektroskopie (MRS) und dem ihr inhärenten Prinzip des sog. chemical shifts gelingt die nicht-invasive in-vivo Analyse verschiedener zerebraler Metabolite. Mittels Protonen (1H)-MRS können so u.a. Rückschlüsse auf die glutamaterge Neurotransmission und mittels Phosphor (31P)-MRS auf den Energie- und strukturbedeutsamen Membranlipid-Stoffwechsel in umschriebenen Lokalisationen des Gehirns gezogen werden. Für diese Arbeit wurden 69 UHR-Patienten (Alter: 26,2 ± 6,2 Jahre) und 61 gesunde Kontrollen (Alter: 25,2 ± 4,8 J.) einer in gleicher Sitzung durchgeführten kombinierten 1H/31P -MRS unterzogen. Der Großteil der Patienten war zum Messzeitpunkt frei von antipsychotischer (neuroleptischer) Medikation. Es wurden insgesamt elf Metabolite untersucht, beidseits im Bereich des dorsolateralen und dorsomedialen präfrontalen Kortex, des anterioren Cingulums, des Thalamus sowie des Hippocampus. Die statistische Auswertung erfolgte u.a. mittels univariater ANOVA bzw. Kruskal-Wallis-Test. Zusammenfassend finden sich bei UHR-Patienten in mehreren Hirnregionen Hinweise für einen verminderten Energieumsatz, was als Hinweis auf ein lokales Funktionsdefizit im Sinne einer Hypofunktion interpretiert werden kann. Durch die zum Teil in gleicher Lokalisation nachweisbare Alteration von Metaboliten des Membran-Umsatzes können somit auch bei UHR-Patienten pathophysiologische Annahmen der ursprünglich für Schizophrenie eingebrachten Membranlipidhypothese partiell untermauert werden. Metabolitenabweichungen, die helfen könnten diejenigen UHR-Patienten zu identifizieren, bei denen eine psychotische Konversion hochwahrscheinlich ist, fanden sich nicht

Post-Franco Theatre

In the multiple realms and layers that comprise the contemporary Spanish theatrical landscape, “crisis” would seem to be the word that most often lingers in the air, as though it were a common mantra, ready to roll off the tongue of so many theatre professionals with such enormous ease, and even enthusiasm, that one is prompted to wonder whether it might indeed be a miracle that the contemporary technological revolution – coupled with perpetual quandaries concerning public and private funding for the arts – had not by now brought an end to the evolution of the oldest of live arts, or, at the very least, an end to drama as we know it

Characteristics of Soil Structure and Greenhouse Gas Fluxes on Ten-Year Old Skid Trails with and without Black Alders (Alnus glutinosa (L.) Gaertn.)

Forest soil compaction caused by heavy machines can cause ecosystem degradation, reduced site productivity and increased greenhouse gas (GHG) emissions. Recent studies investigating the plant-mediated alleviation of soil compaction with black alder showed promising results (Alnus glutinosa). This study aimed to measure soil recovery and GHG fluxes on machine tracks with and without black alders in North-East Switzerland. In 2008, two machine tracks were created under controlled conditions in a European beech (Fagus sylvatica) stand with a sandy loam texture. Directly after compaction, soil physical parameters were measured on one track while the other track was planted with alders. Initial topsoil bulk density and porosity on the track without alders were 1.52 g cm−3 and 43%, respectively. Ten years later, a decrease in bulk density to 1.23 g cm−3 and an increase in porosity to 57% indicated partial structure recovery. Compared with the untreated machine track, alder had no beneficial impact on soil physical parameters. Elevated cumulative N2O emission (+30%) under alder compared with the untreated track could result from symbiotic nitrogen fixation by alder. Overall, CH4 fluxes were sensitive to the effects of soil trafficking. We conclude that black alder did not promote the recovery of a compacted sandy loam while it had the potential to deteriorate the GHG balance of the investigated forest stand

Characteristics of Soil Structure and Greenhouse Gas Fluxes on Ten-Year Old Skid Trails with and without Black Alders (<i>Alnus glutinosa</i> (L.) Gaertn.)

Forest soil compaction caused by heavy machines can cause ecosystem degradation, reduced site productivity and increased greenhouse gas (GHG) emissions. Recent studies investigating the plant-mediated alleviation of soil compaction with black alder showed promising results (Alnus glutinosa). This study aimed to measure soil recovery and GHG fluxes on machine tracks with and without black alders in North-East Switzerland. In 2008, two machine tracks were created under controlled conditions in a European beech (Fagus sylvatica) stand with a sandy loam texture. Directly after compaction, soil physical parameters were measured on one track while the other track was planted with alders. Initial topsoil bulk density and porosity on the track without alders were 1.52 g cm−3 and 43%, respectively. Ten years later, a decrease in bulk density to 1.23 g cm−3 and an increase in porosity to 57% indicated partial structure recovery. Compared with the untreated machine track, alder had no beneficial impact on soil physical parameters. Elevated cumulative N2O emission (+30%) under alder compared with the untreated track could result from symbiotic nitrogen fixation by alder. Overall, CH4 fluxes were sensitive to the effects of soil trafficking. We conclude that black alder did not promote the recovery of a compacted sandy loam while it had the potential to deteriorate the GHG balance of the investigated forest stand

State marker properties of niacin skin sensitivity in ultra-high risk groups for psychosis: an optical reflection spectroscopy study

Impaired niacin sensitivity (NS) is one of the most replicated findings in untreated schizophrenia, and reflects a disturbance of prostaglandin-mediated pathways in association with deregulated arachidonic acid metabolism, pro-inflammatory activation, and vasomotor function. In ultra-high risk individuals (UHR) increased NS was reported recently, pointing towards dynamic alterations of the underlying pathomechanisms in the period preceding psychosis. However, these characteristics are still unresolved in the diverse UHR groups. We tested the hypothesis that NS is attenuated in patients who have transitioned to psychosis and in the Brief Limited Intermittent Psychotic Symptoms (BLIPS, UHR-B) and/or the attenuated symptoms (UHR-A) groups, while it is unchanged or increased in the genetic risk group (UHR-G). Sensitivity to three concentrations (0.1–0.001 M) of aqueous methylnicotinate was tested in 84 UHR patients, 105 first-episode psychosis patients (FEP) and 180 healthy individuals (HC), using optical reflection spectroscopy (ORS). The UHR subgroup and transition/non-transition outcomes were assessed according to PACE criteria using the CAARMS. Psychopathology was assessed using SANS, SAPS, and BPRS or SCL-90-R self-ratings. In 0.001 M data, decreased NS was found in the UHR-B (n = 12), UHR-A (n = 45) and the transition groups (n = 13), similar to the result in FEP. NS in the UHR-G (n = 27) and HC groups did not differ. In the UHR-B and FEP groups, NS and positive symptom scores were inversely correlated. These state marker properties could be used to characterize the intensity of the underlying pathomechanisms during the onset of psychosis or to identify UHR individuals that might benefit from related indicated prevention strategies

Mechanisms of hemispheric specialization: Insights from analyses of connectivity

Traditionally, anatomical and physiological descriptions of hemispheric specialization have focused on hemispheric asymmetries of local brain structure or local functional properties, respectively. This article reviews the current state of an alternative approach that aims at unraveling the causes and functional principles of hemispheric specialization in terms of asymmetries in connectivity. Starting with an overview of the historical origins of the concept of lateralization, we briefly review recent evidence from anatomical and developmental studies that asymmetries in structural connectivity may be a critical factor shaping hemispheric specialization. These differences in anatomical connectivity, which are found both at the intra- and inter-regional level, are likely to form the structural substrate of different functional principles of information processing in the two hemispheres. The main goal of this article is to describe how these functional principles can be characterized using functional neuroimaging in combination with models of functional and effective connectivity. We discuss the methodology of established models of connectivity which are applicable to data from positron emission tomography and functional magnetic resonance imaging and review published studies that have applied these approaches to characterize asymmetries of connectivity during lateralized tasks. Adopting a model-based approach enables functional imaging to proceed from mere descriptions of asymmetric activation patterns to mechanistic accounts of how these asymmetries are caused