@article{JariusRuprechtKleiteretal.2016, author = {Jarius, Sven and Ruprecht, Klemens and Kleiter, Ingo and Borisow, Nadja and Asgari, Nasrin and Pitarokoili, Kalliopi and Pache, Florence and Stich, Oliver and Beume, Lena-Alexandra and H{\"u}mmert, Martin W. and Ringelstein, Marius and Trebst, Corinna and Winkelmann, Alexander and Schwarz, Alexander and Buttmann, Mathias and Zimmermann, Hanna and Kuchling, Joseph and Franciotta, Diego and Capobianco, Marco and Siebert, Eberhard and Lukas, Carsten and Korporal-Kuhnke, Mirjam and Haas, J{\"u}rgen and Fechner, Kai and Brandt, Alexander U. and Schanda, Kathrin and Aktas, Orhan and Paul, Friedemann and Reindl, Markus and Wildemann, Brigitte}, title = {MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 2: Epidemiology, clinical presentation, radiological and laboratory features, treatment responses, and long-term outcome}, series = {Journal of Neuroinflammation}, volume = {13}, journal = {Journal of Neuroinflammation}, number = {280}, doi = {10.1186/s12974-016-0718-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165570}, year = {2016}, abstract = {Background A subset of patients with neuromyelitis optica spectrum disorders (NMOSD) has been shown to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOG-IgG). Objective To describe the epidemiological, clinical, radiological, cerebrospinal fluid (CSF), and electrophysiological features of a large cohort of MOG-IgG-positive patients with optic neuritis (ON) and/or myelitis (n = 50) as well as attack and long-term treatment outcomes. Methods Retrospective multicenter study. Results The sex ratio was 1:2.8 (m:f). Median age at onset was 31 years (range 6-70). The disease followed a multiphasic course in 80\% (median time-to-first-relapse 5 months; annualized relapse rate 0.92) and resulted in significant disability in 40\% (mean follow-up 75 ± 46.5 months), with severe visual impairment or functional blindness (36\%) and markedly impaired ambulation due to paresis or ataxia (25\%) as the most common long-term sequelae. Functional blindness in one or both eyes was noted during at least one ON attack in around 70\%. Perioptic enhancement was present in several patients. Besides acute tetra-/paraparesis, dysesthesia and pain were common in acute myelitis (70\%). Longitudinally extensive spinal cord lesions were frequent, but short lesions occurred at least once in 44\%. Fourty-one percent had a history of simultaneous ON and myelitis. Clinical or radiological involvement of the brain, brainstem, or cerebellum was present in 50\%; extra-opticospinal symptoms included intractable nausea and vomiting and respiratory insufficiency (fatal in one). CSF pleocytosis (partly neutrophilic) was present in 70\%, oligoclonal bands in only 13\%, and blood-CSF-barrier dysfunction in 32\%. Intravenous methylprednisolone (IVMP) and long-term immunosuppression were often effective; however, treatment failure leading to rapid accumulation of disability was noted in many patients as well as flare-ups after steroid withdrawal. Full recovery was achieved by plasma exchange in some cases, including after IVMP failure. Breakthrough attacks under azathioprine were linked to the drug-specific latency period and a lack of cotreatment with oral steroids. Methotrexate was effective in 5/6 patients. Interferon-beta was associated with ongoing or increasing disease activity. Rituximab and ofatumumab were effective in some patients. However, treatment with rituximab was followed by early relapses in several cases; end-of-dose relapses occurred 9-12 months after the first infusion. Coexisting autoimmunity was rare (9\%). Wingerchuk's 2006 and 2015 criteria for NMO(SD) and Barkhof and McDonald criteria for multiple sclerosis (MS) were met by 28\%, 32\%, 15\%, 33\%, respectively; MS had been suspected in 36\%. Disease onset or relapses were preceded by infection, vaccination, or pregnancy/delivery in several cases. Conclusion Our findings from a predominantly Caucasian cohort strongly argue against the concept of MOG-IgG denoting a mild and usually monophasic variant of NMOSD. The predominantly relapsing and often severe disease course and the short median time to second attack support the use of prophylactic long-term treatments in patients with MOG-IgG-positive ON and/or myelitis.}, language = {en} } @phdthesis{Grotemeyer2019, author = {Grotemeyer, Alexander}, title = {Characterisation and application of new optogenetic tools in \(Drosophila\) \(melanogaster\)}, doi = {10.25972/OPUS-17879}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178793}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Since Channelrhodopsins has been described first and introduced successfully in freely moving animals (Nagel et al., 2003 and 2005), tremendous impact has been made in this interesting field of neuroscience. Subsequently, many different optogenetic tools have been described and used to address long-lasting scientific issues. Furthermore, beside the 'classical' Channelrhodopsin-2 (ChR2), basically a cation-selective ion channel, also altered ChR2 descendants, anion selective channels and light-sensitive metabotropic proteins have expanded the optogenetic toolbox. However, in spite of this variety of different tools most researches still pick Channelrhodopsin-2 for their optogenetic approaches due to its well-known kinetics. In this thesis, an improved Channelrhodopsin, Channelrhodopsin2-XXM (ChR2XXM), is described, which might become an useful tool to provide ambitious neuroscientific approaches by dint of its characteristics. Here, ChR2XXM was chosen to investigate the functional consequences of Drosophila larvae lacking latrophilin in their chordotonal organs. Finally, the functionality of GtACR, was checked at the Drosophila NMJ. For a in-depth characterisation, electrophysiology along with behavioural setups was employed. In detail, ChR2XXM was found to have a better cellular expression pattern, high spatiotemporal precision, substantial increased light sensitivity and improved affinity to its chromophore retinal, as compared to ChR2. Employing ChR2XXM, effects of latrophilin (dCIRL) on signal transmission in the chordotonal organ could be clarified with a minimum of side effects, e.g. possible heat response of the chordotonal organ, due to high light sensitivity. Moreover, optogenetic activation of the chordotonal organ, in vivo, led to behavioural changes. Additionally, GtACR1 was found to be effective to inhibit motoneuronal excitation but is accompanied by unexpected side effects. These results demonstrate that further improvement and research of optogenetic tools is highly valuable and required to enable researchers to choose the best fitting optogenetic tool to address their scientific questions.}, subject = {Optogenetik}, language = {en} } @phdthesis{Guan2016, author = {Guan, Chonglin}, title = {Functional and genetic dissection of mechanosensory organs of \(Drosophila\) \(melanogaster\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146220}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {In Drosophila larvae and adults, chordotonal organs (chos) are highly versatile mechanosensors that are essential for proprioception, touch sensation and hearing. Chos share molecular, anatomical and functional properties with the inner ear hair cells of mammals. These multiple similarities make chos powerful models for the molecular study of mechanosensation. In the present study, I have developed a preparation to directly record from the sensory neurons of larval chos (from the lateral chos or lch5) and managed to correlate defined mechanical inputs with the corresponding electrical outputs. The findings of this setup are described in several case studies. (1) The basal functional lch5 parameters, including the time course of response during continuous mechanical stimulation and the recovery time between successive bouts of stimulation, was characterized. (2) The calcium-independent receptor of α-latrotoxin (dCIRL/Latrophilin), an Adhesion class G protein-coupled receptor (aGPCR), is identified as a modulator of the mechanical signals perceived by lch5 neurons. The results indicate that dCIRL/Latrophilin is required for the perception of external and internal mechanical stimuli and shapes the sensitivity of neuronal mechanosensation. (3) By combining this setup with optogenetics, I have confirmed that dCIRL modulates lch5 neuronal activity at the level of their receptor current (sensory encoding) rather than their ability to generate action potentials. (4) dCIRL´s structural properties (e.g. ectodomain length) are essential for the mechanosensitive properties of chordotonal neurons. (5) The versatility of chos also provides an opportunity to study multimodalities at multiple levels. In this context, I performed an experiment to directly record neuronal activities at different temperatures. The results show that both spontaneous and mechanically evoked activity increase in proportion to temperature, suggesting that dCIRL is not required for thermosensation in chos. These findings, from the development of an assay of sound/vibration sensation, to neuronal signal processing, to molecular aspects of mechanosensory transduction, have provided the first insights into the mechanosensitivity of dCIRL. In addition to the functional screening of peripheral sensory neurons, another electrophysiological approach was applied in the central nervous system: dCIRL may impact the excitability of the motor neurons in the ventral nerve cord (VNC). In the second part of my work, whole-cell patch clamp recordings of motor neuron somata demonstrated that action potential firing in the dCirl\(^K\)\(^O\) did not differ from control samples, indicating comparable membrane excitability.}, subject = {Taufliege}, language = {en} }