Publications by authors named "Mittag M"

Genetically encoded calcium (Ca ) indicators (GECIs) are widely used for imaging neuronal activity, yet current limitations of existing red fluorescent GECIs have constrained their applicability. The inherently dim fluorescence and low signal-to-noise ratio of red-shifted GECIs have posed significant challenges. More critically, several red-fluorescent GECIs exhibit photoswitching when exposed to blue light, thereby limiting their applicability in all-optical experimental approaches.

View Article and Find Full Text PDF

Photosynthetic protists, named microalgae, are key players in global primary production. The green microalga Chlamydomonas reinhardtii is a well-studied model organism. In nature, it dwells in acetate-rich paddy rice soil, which is not mimicked by standard liquid laboratory conditions.

View Article and Find Full Text PDF

Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line, and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity.

View Article and Find Full Text PDF

Purpose: To propose a paradigm change for the validation procedures of medication adherence questionnaires.

Methods: A total of 121 validation procedures of unique questionnaires for medication adherence were analyzed.

Results: "Construct validity" and "internal consistency" were most often assessed, and test results varied largely.

View Article and Find Full Text PDF

Algae and bacteria have co-occurred and coevolved in common habitats for hundreds of millions of years, fostering specific associations and interactions such as mutualism or antagonism. These interactions are shaped through exchanges of primary and secondary metabolites provided by one of the partners. Metabolites, such as N-sources or vitamins, can be beneficial to the partner and they may be assimilated through chemotaxis towards the partner producing these metabolites.

View Article and Find Full Text PDF

Photosynthetic protists, known as microalgae, are key contributors to primary production on Earth. Since early in evolution, they coexist with bacteria in nature, and their mode of interaction shapes ecosystems. We have recently shown that the bacterium acts algicidal on the microalga It secretes a cyclic lipopeptide and a polyyne that deflagellate, blind, and lyse the algae [P.

View Article and Find Full Text PDF

Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity.

View Article and Find Full Text PDF

Algae encode up to five different types of cryptochrome photoreceptors. So far, relatively little is known about the biological functions of the DASH (Drosophila, Arabidopsis, Synechocystis and Homo)-type cryptochromes. The green alga Chlamydomonas reinhardtii encodes two of them.

View Article and Find Full Text PDF

Dendritic spines are crucial for excitatory synaptic transmission as the size of a spine head correlates with the strength of its synapse. The distribution of spine head sizes follows a lognormal-like distribution with more small spines than large ones. We analysed the impact of synaptic activity and plasticity on the spine size distribution in adult-born hippocampal granule cells from rats with induced homo- and heterosynaptic long-term plasticity and CA1 pyramidal cells from Munc13-1/Munc13-2 knockout mice with completely blocked synaptic transmission.

View Article and Find Full Text PDF

Background: Hand disinfection (HD) is known to be the single most effective prevention measure to avoid nosocomial infections, but the compliance rate (CR) remains low. The aim of this study was to determine the incidence of HD opportunities and the CR during the treatment of critically ill patients. One special focus was on glove usage to determine whether gloves were substituted for HD.

View Article and Find Full Text PDF

Microglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglial motility and significance for synapse stability, especially in the hippocampus during adulthood, remain widely unresolved.

View Article and Find Full Text PDF

Neuronal hyperexcitability is a pathological characteristic of Alzheimer's disease (AD). Three main mechanisms have been proposed to explain it: (i) dendritic degeneration leading to increased input resistance, (ii) ion channel changes leading to enhanced intrinsic excitability, and (iii) synaptic changes leading to excitation-inhibition (E/I) imbalance. However, the relative contribution of these mechanisms is not fully understood.

View Article and Find Full Text PDF

Background: The reform of the German psychotherapy directive in 2017 resulted in several changes for non-hospital-based psychotherapists. We examined whether patients received psychotherapy following their initial consultation more frequently after the reform than before.

Methods: Using records from psychotherapy practices in a retrospective cohort study, we investigated the frequency of a psychotherapy after the patients' initial consultation.

View Article and Find Full Text PDF

We developed a family of genetically encoded serotonin (5-HT) sensors (sDarken) on the basis of the native 5-HT1A receptor and circularly permuted GFP. sDarken 5-HT sensors are bright in the unbound state and diminish their fluorescence upon binding of 5-HT. Sensor variants with different affinities for serotonin were engineered to increase the versatility in imaging of serotonin dynamics.

View Article and Find Full Text PDF

The antagonistic bacterium Pseudomonas protegens secretes the cyclic lipopeptide (CLiP) orfamide A, which triggers a Ca signal causing rapid deflagellation of the microalga Chlamydomonas reinhardtii. We performed chemical synthesis of orfamide A derivatives and used an aequorin reporter line to measure their Ca responses. Immobilization of algae was studied using a modulator and mutants of transient receptor potential (TRP)-type channels.

View Article and Find Full Text PDF

Interactions between microorganisms are often mediated by specialized metabolites. Although the structures and biosynthesis of these compounds may have been elucidated, microbes exist within complex microbiomes and chemical signals can thus also be subject to community-dependent modifications. Increasingly powerful chemical and biological tools allow to shed light on this poorly understood aspect of chemical ecology.

View Article and Find Full Text PDF

Circadian clocks govern temporal programs in the green lineage (Chloroplastida) as they do in other photosynthetic pro- and eukaryotes, bacteria, fungi, animals, and humans. Their physiological properties, including entrainment, phase responses, and temperature compensation, are well conserved. The involvement of transcriptional/translational feedback loops in the oscillatory machinery and reversible phosphorylation events are also maintained.

View Article and Find Full Text PDF

A total synthesis of the cyclic lipodepsipeptide natural product orfamide A was achieved. By developing a synthesis format using an aminoacid ester building block and SPPS protocol adaptation, a focused library of target compounds was obtained, in high yield and purity. Spectral and LC-HRMS data of all library members with the isolated natural product identified the Leu residue to be d- and the 3'-OH group to be R-configured.

View Article and Find Full Text PDF

Research on children and adults with developmental dyslexia-a specific difficulty in learning to read and spell-suggests that phonological deficits in dyslexia are linked to basic auditory deficits in temporal sampling. However, it remains undetermined whether such deficits are already present in infancy, especially during the sensitive period when the auditory system specializes in native phoneme perception. Because dyslexia is strongly hereditary, it is possible to examine infants for early predictors of the condition before detectable symptoms emerge.

View Article and Find Full Text PDF

A plant-like cryptochrome of diatom microalgae, CryP, acts as a photoreceptor involved in transcriptional regulation. It contains FAD and 5,10-methenyltetrahydrofolate as chromophores. Here, we demonstrate that the unstructured C-terminal extension (CTE) of CryP has an influence on the redox state of the flavin.

View Article and Find Full Text PDF

Algae are photosynthetic eukaryotic (micro-)organisms, lacking roots, leaves, and other organs that are typical for land plants. They live in freshwater, marine, or terrestrial habitats. Together with the cyanobacteria they contribute to about half of global carbon fixation.

View Article and Find Full Text PDF

Reducing neuronal size results in less membrane and therefore lower input conductance. Smaller neurons are thus more excitable, as seen in their responses to somatic current injections. However, the impact of a neuron's size and shape on its voltage responses to dendritic synaptic activation is much less understood.

View Article and Find Full Text PDF

Background: COVID-19 comprises several severity stages ranging from oligosymptomatic disease to multi-organ failure and fatal outcomes. The mechanisms why COVID-19 is a mild disease in some patients and progresses to a severe multi-organ and often fatal disease with respiratory failure are not known. Biomarkers that predict the course of disease are urgently needed.

View Article and Find Full Text PDF

Algae are key contributors to global carbon fixation and form the basis of many food webs. In nature, their growth is often supported or suppressed by microorganisms. The bacterium Pf-5 arrests the growth of the green unicellular alga , deflagellates the alga by the cyclic lipopeptide orfamide A, and alters its morphology [P.

View Article and Find Full Text PDF