effect of selegiline and clomipramine

Deckblatt-Impressum persönlicher Dank Inhaltsverzeichnis Abkürzungsverzeichnis Einleitung Literaturübersicht Material und Methoden Ergebnisse Diskussion Zusammenfassung Summary Literaturverzeichnis Danksagung SelbständigkeitserklärungVersuchsapparatur wurde die Skinner Box verwendet, die mit zwei Tasten ausgestattet war. Beim Betätigen der einen Taste erhielt das Versuchstier eine kleine sofort erhältliche Belohnung und beim Betätigen der anderen Taste, wurde die Belohnung erst nach einer Zeitverzögerung ausgegeben. Der erste Schritt der Methodenentwicklung war die Erfassung der versuchsrelevanten Parameter, auf denen die Methode aufgebaut wurde. Dazu wurden drei unterschiedliche Rattenstämme bzw. Zuchtlinien (Fischer/Winkelmann-, Wistar/Winkelmann-, und Wistar/BgVV-Ratten) verwendet. Bereits bei der Erfassung des ersten Versuchsparameters (die Anzahl der notwendigen Trainingstage bis zum Erlernen des Tastendrückens) zeigten sich deutliche Unterschiede im Lernverhalten zwischen den unterschiedlichen Rattenstämmen. Die Fischer/Winkelmann-Ratten wiesen im Vergleich zu den Wistar/Winkelmann- und Wistar/BgVV-Ratten einen sehr niedrigen Lernerfolg auf, welches einem geringen Explorationsverhalten zugeschrieben wurde. Das geringe Explorationsverhalten hing mit großer Wahrscheinlichkeit mit der Angst vor neuer Umgebung zusammen. Aufgrunddessen konnten die Fischer/Winkelmann-Ratten nicht mehr verwendet werden und wurden aus allen weiteren Versuchen ausgeschlossen. Weitere zu ermittelnde Versuchsparameter waren, die Dauer der täglichen Versuchszeit (Parameter II), die Anzahl der Futterpellets der großen Belohnung (Parameter III) und die maximale Zeitverzögerung vor Ausgabe der großen Belohnung (Parameter IV). Aus der Erfassung der versuchsrelevanten Parameter konnte gleichzeitig ein für die pharmakologische Untersuchung geeignetes Trainingsprogramm entwickelt werden, welches aus insgesamt drei aufeinanderfolgenden Lernphasen bestand. Das Absolvieren des Trainingsprogramms war eine Grundvoraussetzung für die Anwendung der delay of reinforcement -Methode. Die pharmakologischen Untersuchungen wurden an zwei unterschiedlichen Ratten-Zuchtlinien, Wistar/Winkelmann-und Wistar/BgVV- Ratten, durchgeführt. Bei den auserwählten Pharmaka handelte es sich um Clomipramin, Selegilin und Diazepam. Die Wistar/Winkelmann-Ratten zeigten nach Applikation des Clomipramins keine Verhaltensänderungen. Im Vergleich dazu nahm Clomipramin bei den Wistar/BgVV-Ratten Einfluß auf die Aktivität. Mit steigender Dosierung verminderte sich die Aktivität der Tiere. Clomipramin hatte allerdings weder bei den Wistar/Winkelmann- noch bei den Wistar/BgVV- Ratten Einfluß auf die Impulsivität. Selegilin erzielte bei den Wistar/BgVV- Ratten schon bei niedriger Dosierung eine Steigerung der Aktivität. Die Wistar /Winkelmann-Ratten zeigten erst nach Gabe einer mittleren Dosierung eine erhöhte Aktivität. Selegilin hatte keinerlei Wirkung auf die Impulsivität der Wistar/Winkelmann- und Wistar/BgVV-Ratten. Nach Applikation des Diazepams in der höchsten Dosierung wurde die Impulsivität der Wistar/Winkelmann-Ratten erhöht. Dagegen zeigten die Wistar/BgVV-Ratten nach Gabe des Diazepams auch in unterschiedlichen Dosierungen keinerlei Verhaltensänderungen. Diazepam hatte keine Wirkung auf die Impulsivität der Wistar/BgVV-Ratten. Die Ergebnisse zeigen, daß schon bei der Methodenentwicklung die Fischer-Ratten und die Wistar-Ratten ein ganz unterschiedliches Ausgangsverhalten aufwiesen. Ebenfalls deuten die Ergebnisse darauf hin, dass die Wistar/Winkelmann- und die Wistar/BgVV-Ratten unterschiedlich auf die Gabe der Pharmaka reagierten. Daher sollten Stammes-bzw. Zuchtlinienunterschiede bei zukünftigen Untersuchungen berücksichtigt werden.Impulsiveness is seen as a clinical symptom in several psychiatric disorders. It is used as a diagnostic criterion for impulsive-control disorders, personality disorders, borderline personality disorders, antisocial personality disorders and in mania. It can be found in the expression of different behaviours. In human medicine impulsivity is commonly linked to disorders such as impulsive aggression, violent behaviour, but also in drinking or sexual behaviour. In veterinary medicine impulsivity is not just referred to aggressive behaviour, what can be defined as reduction or a complete lack of warning signals previous to attack. It is probably also linked to behavioural disorders such as seperation anxiety, storm and noise phobia. Impulsivity is more a sign than a diagnosis itself. So far, the construction of impulsiveness has not been sufficiently clarified. It has been proposed that there is an inverse relationship between the central serotonergic system and impulsive behaviour. Particularly the serotonergic metabolite 5-hydroxyindoleacetic (5-HIAA) seems to play an important role in the regulatory mechanisms of impulsivity. Research in humans and animals demonstrates the association between impulsive behaviour resp. lack of impulsive-control with a decreased level of 5-HIAA. It is a very important question how to measure impulsive behaviour. Some animal models have been developed, but not very extinsively. The delay of reinforcement method is one of the methods, which stand the test. Animals have to choose between a single pellet (small reinforcer) delivered immediately or a larger amount of food pellets (large reinforcer) delivered after a delay. The preference for the immediate reward, that means the intolerance to delay has been proposed to reflect impulsive behaviour, conversely, preference for the delayed reward would indicate self-contol. The aim of this study is the development of a method for measuring impulsivity in rats, what does not exist in research institutes in Germany so far. Based on the delay of reinforcement method by EVENDEN and RYAN (1996) the present study used the Skinner Box with two different levers. The development of the method includes a period of four weeks for conditioning rats to combine lever pressing with emission of food. They also have to distinguish between the two different levers. Rats were given the choice between a single food pellet (small reinforcer) delivered immediately or a large amount of 12 pellets (large reinforcer) delivered after a delay. Before using a conditioning program it is very important to figure out how many days for conditioning rats on lever pressing are required. Other components for developing a method for measuring impulsivity are also important, such as duration of the daily session, amount of food pellets as large reward and the maximum of delay before delivering the large reward. With knownledge of all these aspects a conditioning program for rats has been developed. The conditioning of rats is the basic for using the delay of reinforcement. Three rat strains (Fischer/Winkelmann, Wistar/Winkelmann, Wistar/BgVV) were used. During the training session the Fischer/Winkelmann- rats did not explore the chamber and therefore did not start pressing the levers. The Fischer-rats were not suitable for the experiments of our study. The pharmacological investigations were carried out on two different Wistar stocks (Wistar/Winkelmann and Wistar/BgVV). We investigated whether impulsive behaviour of Wistar/Winkelmann-rats and Wistar/BgVV-rats is affected by treatment with clomipramine, selegiline or diazepam. The behaviour of Wistar /Winkelmann-rats was not significantly affected by treatment with clomipramine, whereas the number of lever presses by Wistar/BgVV-rats was decreased. Clomipramine reduced the activity of Wistar/BgVV-rats. Indeed, clomipramine had neither influence on impulsive behaviour of Wistar /Winkelmann-rats nor on impulsive behaviour of Wistar/BgVV-rats. Selegiline significantly increased the activity of Wistar/Winkelmann-rats and Wistar /BgVV-rats, but did not influence the impulsive behaviour of both Wistar stocks. The application of the highest dose of diazepam in our experiments induced an increase of the frequency of choice of the small reward by Wistar /Winkelmann-rats. Therefore, diazepam increased the impulsivity of Wistar /Winkelmann-rats. The impulsive behaviour of Wistar/BgVV-rats was not affected by treatment with diazepam. In our study Fischer-rats and Wistar-rats showed different baseline levels of exploratory behaviour. Fischer-rats appear to be more anxious than Wistar-rats. Additionally, it appears that the different effects of diazepam on behaviour of Wistar/Winkelmann-rats and Wistar/BgVV- rats can be traced back to differences of their base impulsivity-related behaviour. Differences in the baseline behaviour might have an influence on the effects of pharmacotherapeutics and could produce both false or negative results. Strain and stock differences should be taken into consideration in future investigations. In conclusion, there is a necessity to develop new therapeutics agents for treatment impulsivity both in human medicine and veterinary science. Hence, further work is required on a similar approach to improve animal models for measuring impulsivity and beyond it getting specific knowledge of serotonergic processes in impulsive-related behaviour

A Combined Clinical and Serum Biomarker-Based Approach May Allow Early Differentiation Between Patients With Minor Stroke and Transient Ischemic Attack as Well as Mid-term Prognostication

Background: Early differentiation between transient ischemic attack (TIA) and minor ischemic stroke (MIS) impacts on the patient’s individual diagnostic work-up and treatment. Furthermore, estimations regarding persisting impairments after MIS are essential to guide rehabilitation programs. This study evaluated a combined clinical- and serum biomarker-based approach for the differentiation between TIA and MIS as well as the mid-term prognostication of the functional outcome, which is applicable within the first 24 h after symptom onset. Methods: Prospectively collected data were used for a retrospective analysis including the neurological deficit at admission (National Institutes of Health Stroke Scale, NIHSS) and the following serum biomarkers covering different pathophysiological aspects of stroke: Coagulation (fibrinogen, antithrombin), inflammation (C reactive protein), neuronal damage in the cellular [neuron specific enolase], and the extracellular compartment [matrix metalloproteinase-9, hyaluronic acid]. Further, cerebral magnetic resonance imaging was performed at baseline and day 7, while functional outcome was evaluated with the modified Rankin Scale (mRS) after 3, 6, and 12 months. Results: Based on data from 96 patients (age 64 ± 14 years), 23 TIA patients (NIHSS 0.6 ± 1.1) were compared with 73 MIS patients (NIHSS 2.4 ± 2.0). In a binary logistic regression analysis, the combination of NIHSS and serum biomarkers differentiated MIS from TIA with a sensitivity of 91.8% and a specificity of 60.9% [area under the curve (AUC) 0.84]. In patients with NIHSS 0 at admission, this panel resulted in a still acceptable sensitivity of 81.3% (specificity 71.4%, AUC 0.69) for the differentiation between MIS (n = 16) and TIA (n = 14). By adding age, remarkable sensitivities of 98.4, 100, and 98.2% for the prediction of an excellent outcome (mRS 0 or 1) were achieved with respect to time points investigated within the 1-year follow-up. However, the specificity was moderate and decreased over time (83.3, 70, 58.3%; AUC 0.96, 0.92, 0.91). Conclusion: This pilot study provides evidence that the NIHSS combined with selected serum biomarkers covering pathophysiological aspects of stroke may represent a useful tool to differentiate between MIS and TIA within 24 h after symptom onset. Further, this approach may accurately predict the mid-term outcome in minor stroke patients, which might help to allocate rehabilitative resources

The Effects of Selective Inhibition of Histone Deacetylase 1 and 3 in Huntington’s Disease Mice

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease characterized by a late clinical onset of psychiatric, cognitive, and motor symptoms. Transcriptional dysregulation is an early and central disease mechanism which is accompanied by epigenetic alterations in HD. Previous studies demonstrated that targeting transcriptional changes by inhibition of histone deacetylases (HDACs), especially the class I HDACs, provides therapeutic effects. Yet, their exact mechanisms of action and the features of HD pathology, on which these inhibitors act remain to be elucidated. Here, using transcriptional profiling, we found that selective inhibition of HDAC1 and HDAC3 by RGFP109 alleviated transcriptional dysregulation of a number of genes, including the transcription factor genes Neurod2 and Nr4a2, and gene sets and programs, especially those that are associated to insulin-like growth factor pathway, in the striatum of R6/1 mice. RGFP109 treatment led to a modest improvement of the motor skill learning and coordination deficit on the RotaRod test, while it did not alter the locomotor and anxiety-like phenotypes in R6/1 animals. We also found, by volumetric MRI, a widespread brain atrophy in the R6/1 mice at the symptomatic disease stage, on which RGFP109 showed no significant effects. Collectively, our combined work suggests that specific HDAC1 and HDAC3 inhibition may offer benefits for alleviating the motor phenotypic deficits and transcriptional dysregulation in HD

Early lactate and glucose kinetics following return to spontaneous circulation after out-of-hospital cardiac arrest

OBJECTIVE: Lactate has been shown to be preferentially metabolized in comparison to glucose after physiological stress, such as strenuous exercise. Derangements of lactate and glucose are common after out-of-hospital cardiac arrest (OHCA). Therefore, we hypothesized that lactate decreases faster than glucose after return-to-spontaneous-circulation (ROSC) after OHCA. RESULTS: We included 155 OHCA patients in our analysis. Within the first 8 h of presentation to the emergency department, 843 lactates and 1019 glucoses were available, respectively. Lactate decreased to 50% of its initial value within 1.5 h (95% CI [0.2-3.6 h]), while glucose halved within 5.6 h (95% CI [5.4-5.7 h]). Also, in the first 8 h after presentation lactate decreases more than glucose in relation to their initial values (lactate 72.6% vs glucose 52.1%). In patients with marked hyperlactatemia after OHCA, lactate decreased expediently while glucose recovered more slowly, whereas arterial pH recovered at a similar rapid rate as lactate. Hospital non-survivors (N = 82) had a slower recovery of lactate (P = 0.002) than survivors (N = 82). The preferential clearance of lactate underscores its role as a prime energy substrate, when available, during recovery from extreme stress

Expression of HMB45, MelanA and SOX10 is rare in non-small cell lung cancer

Background: Non-small cell lung cancer (NSCLC) and melanoma are frequent entities in routine diagnostics. Whereas the differential diagnosis is usually straight forward based on histomorphology, it can be challenging in poorly differentiated tumors as melanoma may mimic various histological patterns. Distinction of the two entities is of outmost importance as both are treated differently. HMB45 and MelanA are recommended immunohistological markers for melanoma in this scenario. SOX10 has been described as an additional marker for melanoma. However, comprehensive large-scale data about the expression of melanoma markers in NSCLC tumor tissue specimen are lacking so far. Methods: Therefore, we analyzed the expression of these markers in 1085 NSCLC tumor tissue samples. Tissue microarrays of NSCLC cases were immunohistochemically stained for HMB45, MelanA, and SOX10. Positivity of a marker was defined as ≥1% positive tumor cells. Results: In 1027 NSCLC tumor tissue samples all melanoma as well as conventional immunohistochemical markers for NSCLC could be evaluated. HMB45, MelanA, and SOX10 were positive in 1 (< 1%), 0 (0%) and 5 (< 1%) cases. The HMB45 positive case showed co-expression of SOX10 and was classified as large cell carcinoma. Three out of five SOX10 positive cases were SqCC and one case was an adenosquamous carcinoma. Conclusions: Expression of HMB45, MelanA and SOX10 is evident but exceedingly rare in NSCLC cases. Together with conventional immunomarkers a respective marker panel allows a clear-cut differential diagnosis even in poorly differentiated tumors

RNA chaperone activity of L1 ribosomal proteins: phylogenetic conservation and splicing inhibition

RNA chaperone activity is defined as the ability of proteins to either prevent RNA from misfolding or to open up misfolded RNA conformations. One-third of all large ribosomal subunit proteins from E. coli display this activity, with L1 exhibiting one of the highest activities. Here, we demonstrate via the use of in vitro trans- and cis-splicing assays that the RNA chaperone activity of L1 is conserved in all three domains of life. However, thermophilic archaeal L1 proteins do not display RNA chaperone activity under the experimental conditions tested here. Furthermore, L1 does not exhibit RNA chaperone activity when in complexes with its cognate rRNA or mRNA substrates. The evolutionary conservation of the RNA chaperone activity among L1 proteins suggests a functional requirement during ribosome assembly, at least in bacteria, mesophilic archaea and eukarya. Surprisingly, rather than facilitating catalysis, the thermophilic archaeal L1 protein from Methanococcus jannaschii (MjaL1) completely inhibits splicing of the group I thymidylate synthase intron from phage T4. Mutational analysis of MjaL1 excludes the possibility that the inhibitory effect is due to stronger RNA binding. To our knowledge, MjaL1 is the first example of a protein that inhibits group I intron splicing

Molecular quantification and differentiation of Candida species in biological specimens of patients with liver cirrhosis

Patients with liver cirrhosis are susceptible to fungal infections. Due to low sensitivity of culture-based methods, we applied a real-time PCR assay targeting the 18S rRNA gene in combination with direct sequencing and terminal-restriction fragment length polymorphism (T-RFLP) in order to establish a novel tool to detect fungal DNA and to quantify and differentiate Candida DNA, also in polyfungal specimens. In total, 281 samples (blood n=135, ascites n=92, duodenal fluid n=54) from 135 patients with liver cirrhosis and 52 samples (blood n=26, duodenal fluid n=26) from 26 control patients were collected prospectively. Candida DNA was quantified in all samples. Standard microbiological culture was performed for comparison. Blood and ascites samples, irrespective of the patient cohort, showed a method-independent low fungal detection rate of approximately 1%, and the Candida DNA content level did not exceed 3.0x101 copies ml-1 in any sample. In contrast, in duodenal fluid of patients with liver cirrhosis high fungal detection rates were discovered by using both PCR- and culture-based techniques (81.5% vs. 66.7%; p=0.123) and the median level of Candida DNA was 3.8x105 copies ml-1 (2.3x102-6.3x109). In cirrhosis and controls, fungal positive culture results were confirmed by PCR in 96% and an additional amount of 44% of culture negative duodenal samples were PCR positive. Using T-RFLP analysis in duodenal samples, overall 85% of results from microbial culture were confirmed and in 75% of culture-negative but PCR-positive samples additional Candida species could be identified. In conclusion, PCR-based methods and subsequent differentiation of Candida DNA might offer a quick approach to identifying Candida species without prior cultivation

Structural Correlates of Taste and Smell Loss in Encephalitis Disseminata

BACKGROUND: Olfactory dysfunction in MS patients is reported in the literature. MRI of the olfactory bulb (OB) is discussed as a promising new testing method for measuring olfactory function (OF). Aim of this study was to explore reasons for and optimize the detection of olfactory dysfunction in MS patients with MRI. MATERIALS AND METHODS: OB and olfactory brain volume was assessed within 34 MS patients by manual segmentation. Olfactory function was tested using the Threshold-Discrimination-Identification-Test (TDI), gustatory function was tested using Taste Strips (TST). RESULTS: 41% of the MS patients displayed olfactory dysfunction (8% of the control group), 16% displayed gustatory dysfunction (5% of the control group). There was a correlation between the OB volume and the number and volume of MS lesions in the olfactory brain. Olfactory brain volume correlated with the volume of lesions in the olfactory brain and the EDSS score. The TST score correlated with the number and volume of lesions in the olfactory brain. CONCLUSION: The correlation between a higher number and volume of MS lesions with a decreased OB and olfactory brain volume could help to explain olfactory dysfunction

Thought experiment: Decoding cognitive processes from the fMRI data of one individual

Wegrzyn M, Aust J, Barnstorf L, et al. Thought experiment: Decoding cognitive processes from the fMRI data of one individual. PLOS ONE. 2018;13(9): e0204338.Cognitive processes, such as the generation of language, can be mapped onto the brain using fMRI. These maps can in turn be used for decoding the respective processes from the brain activation patterns. Given individual variations in brain anatomy and organization, analyzes on the level of the single person are important to improve our understanding of how cognitive processes correspond to patterns of brain activity. They also allow to advance clinical applications of fMRI, because in the clinical setting making diagnoses for single cases is imperative. In the present study, we used mental imagery tasks to investigate language production, motor functions, visuo-spatial memory, face processing, and resting-state activity in a single person. Analysis methods were based on similarity metrics, including correlations between training and test data, as well as correlations with maps from the NeuroSynth meta-analysis. The goal was to make accurate predictions regarding the cognitive domain (e.g. language) and the specific content (e.g. animal names) of single 30-second blocks. Four teams used the dataset, each blinded regarding the true labels of the test data. Results showed that the similarity metrics allowed to reach the highest degrees of accuracy when predicting the cognitive domain of a block. Overall, 23 of the 25 test blocks could be correctly predicted by three of the four teams. Excluding the unspecific rest condition, up to 10 out of 20 blocks could be successfully decoded regarding their specific content. The study shows how the information contained in a single fMRI session and in each of its single blocks can allow to draw inferences about the cognitive processes an individual engaged in. Simple methods like correlations between blocks of fMRI data can serve as highly reliable approaches for cognitive decoding. We discuss the implications of our results in the context of clinical fMRI applications, with a focus on how decoding can support functional localization

Music and the brain: disorders of musical listening

The study of the brain bases for normal musical listening has advanced greatly in the last 30 years. The evidence from basic and clinical neuroscience suggests that listening to music involves many cognitive components with distinct brain substrates. Using patient cases reported in the literature, we develop an approach for understanding disordered musical listening that is based on the systematic assessment of the perceptual and cognitive analysis of music and its emotional effect. This approach can be applied both to acquired and congenital deficits of musical listening, and to aberrant listening in patients with musical hallucinations. Both the bases for normal musical listening and the clinical assessment of disorders now have a solid grounding in systems neuroscience