@article{GarciaMartinezBrunkAvalosetal.2015, author = {Garc{\´i}a-Mart{\´i}nez, Jorge and Brunk, Michael and Avalos, Javier and Terpitz, Ulrich}, title = {The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {7798}, doi = {10.1038/srep07798}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149049}, year = {2015}, abstract = {Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO\(^{-}\) mutant and carO\(^{+}\) control strains showed a faster development of light-exposed carO-germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin.}, language = {en} } @article{DeaneBrunkCurranetal.2020, author = {Deane, Katrina E. and Brunk, Michael G. K. and Curran, Andrew W. and Zempeltzi, Marina M. and Ma, Jing and Lin, Xiao and Abela, Francesca and Aksit, S{\"u}meyra and Deliano, Matthias and Ohl, Frank W. and Happel, Max F. K.}, title = {Ketamine anaesthesia induces gain enhancement via recurrent excitation in granular input layers of the auditory cortex}, series = {The Journal of Physiology}, volume = {598}, journal = {The Journal of Physiology}, number = {13}, doi = {10.1113/JP279705}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216123}, pages = {2741 -- 2755}, year = {2020}, abstract = {Ketamine is commonly used as an anaesthetic agent and has more recently gained attention as an antidepressant. It has been linked to increased stimulus-locked excitability, inhibition of interneurons and modulation of intrinsic neuronal oscillations. However, the functional network mechanisms are still elusive. A better understanding of these anaesthetic network effects may improve upon previous interpretations of seminal studies conducted under anaesthesia and have widespread relevance for neuroscience with awake and anaesthetized subjects as well as in medicine. Here, we investigated the effects of anaesthetic doses of ketamine (15 mg kg\(^{-1}\) h\(^{-1}\)i.p.) on the network activity after pure-tone stimulation within the auditory cortex of male Mongolian gerbils (Meriones unguiculatus). We used laminar current source density (CSD) analysis and subsequent layer-specific continuous wavelet analysis to investigate spatiotemporal response dynamics on cortical columnar processing in awake and ketamine-anaesthetized animals. We found thalamocortical input processing within granular layers III/IV to be significantly increased under ketamine. This layer-dependent gain enhancement under ketamine was not due to changes in cross-trial phase coherence but was rather attributed to a broadband increase in magnitude reflecting an increase in recurrent excitation. A time-frequency analysis was indicative of a prolonged period of stimulus-induced excitation possibly due to a reduced coupling of excitation and inhibition in granular input circuits - in line with the common hypothesis of cortical disinhibition via suppression of GABAergic interneurons.}, language = {en} } @article{BrunkSputhDooseetal.2018, author = {Brunk, Michael and Sputh, Sebastian and Doose, S{\"o}ren and van de Linde, Sebastian and Terpitz, Ulrich}, title = {HyphaTracker: An ImageJ toolbox for time-resolved analysis of spore germination in filamentous fungi}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, doi = {10.1038/s41598-017-19103-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221691}, year = {2018}, abstract = {The dynamics of early fungal development and its interference with physiological signals and environmental factors is yet poorly understood. Especially computational analysis tools for the evaluation of the process of early spore germination and germ tube formation are still lacking. For the time-resolved analysis of conidia germination of the filamentous ascomycete Fusarium fujikuroi we developed a straightforward toolbox implemented in ImageJ. It allows for processing of microscopic acquisitions (movies) of conidial germination starting with drift correction and data reduction prior to germling analysis. From the image time series germling related region of interests (ROIs) are extracted, which are analysed for their area, circularity, and timing. ROIs originating from germlings crossing other hyphae or the image boundaries are omitted during analysis. Each conidium/hypha is identified and related to its origin, thus allowing subsequent categorization. The efficiency of HyphaTracker was proofed and the accuracy was tested on simulated germlings at different signal-to-noise ratios. Bright-field microscopic images of conidial germination of rhodopsin-deficient F. fujikuroi mutants and their respective control strains were analysed with HyphaTracker. Consistent with our observation in earlier studies the CarO deficient mutant germinated earlier and grew faster than other, CarO expressing strains.}, language = {en} }