Functional neuroanatomy of the rhinophore of Aplysia punctata

BACKGROUND: For marine snails, olfaction represents a crucial sensory modality for long-distance reception, as auditory and visual information is limited. The posterior tentacle of Aplysia, the rhinophore, is a chemosensory organ and several behavioural studies showed that the rhinophores can detect pheromones, initiate orientation and locomotion toward food. However the functional neuroanatomy of the rhinophore is not yet clear. Here we apply serotonin-immunohistochemistry and fluorescent markers in combination with confocal microscopy as well as optical recording techniques to elucidate the structure and function of the rhinophore of the sea slug Aplysia punctata. RESULTS: With anatomical techniques an overview of the neuroanatomical organization of the rhinophore is presented. Labelling with propidium iodide revealed one layer of cell nuclei in the sensory epithelium and densely packed cell nuclei beneath the groove of the rhinophore, which extends to about two third of the total length of the rhinophore. Serotonin immunoreactivity was found within the olfactory glomeruli underneath the epithelium as well as in the rhinophore ganglion. Retrograde tracing from the rhinophore ganglion with 4-(4-(dihexadecylamino)styryl)-N-methylpyridinium iodide (DiA) demonstrated the connection of glomeruli with the ganglion. Around 36 glomeruli (mean diameter 49 μm) were counted in a single rhinophore. Fluorimetric measurements of intracellular Ca(2+ )levels using Fura-2 AM loading revealed Ca(2+)-responses within the rhinophore ganglion to stimulation with amino acids. Bath application of different amino acids revealed differential responses at different positions within the rhinophore ganglion. CONCLUSION: Our neuroanatomical study revealed the number and position of glomeruli in the rhinophore and the rhinophore ganglion as processing stage of sensory information. Serotonin-immunoreactive processes were found extensively within the rhinophore, but was not detected within any peripheral cell body. Amino acids were used as olfactory stimuli in optical recordings and induced sensory responses in the rhinophore ganglion. The complexity of changes in intracellular Ca(2+)-levels indicates, that processing of odour information takes place within the rhinophore ganglion. Our neuroanatomical and functional studies of the rhinophore open up a new avenue to analyze the olfactory system in Aplysia

Extracting the Behaviorally Relevant Stimulus: Unique Neural Representation of Farnesol, a Component of the Recruitment Pheromone of Bombus terrestris

Strube-Bloss M, Brown A, Spaethe J, Schmitt T, Rössler W. Extracting the Behaviorally Relevant Stimulus: Unique Neural Representation of Farnesol, a Component of the Recruitment Pheromone of Bombus terrestris. PLOS ONE. 2015;10(9): e0137413

HCMV-infection in a human arterial organ culture model: effects on cell proliferation and neointimal hyperplasia

<p>Abstract</p> <p>Background</p> <p>The impact of infections with the human cytomegalovirus (HCMV) for the development of atherosclerosis and restenosis is still unclear. Both a clear correlation and no correlation at all have been reported in clinical, mostly serological studies. In our study we employed a human non-injury ex vivo organ culture model to investigate the effect of an in vitro permissive HCMV-infection on cell proliferation and neointimal hyperplasia for a period of 56 days.</p> <p>Results</p> <p>During routine-nephrectomies parts of renal arteries from 71 patients were obtained and prepared as human organ cultures. Cell free HCMV infection was performed with the fibroblast adapted HCMV strain AD169, the endotheliotropic strain TB40E, and a clinical isolate (AN 365). After 3, 7, 14, 21, 28, 35, and 56 days in culture staining of HCMV-antigens was carried out and reactive cell proliferation and neointimal thickening were analysed. Successful HCMV-infection was accomplished with all three virus strains studied. During the first 21 days in organ culture no cell proliferation or neointimal hyperplasia was detected. At day 35 and day 56 moderate cell proliferation and neointimal hyperplasia was found both in HCMV-infected segments and mock infected controls. Neointimal hyperplasia in productively HCMV-infected segments was lower than in non infected at day 35 and day 56, but relatively higher after infection with the endotheliotropic TB40E in comparison with the two other strains.</p> <p>Conclusion</p> <p>The data do not support the hypothesis that HCMV-infection triggers restenosis via a stimulatory effect on cell proliferation and neointimal hyperplasia in comparison to non infected controls. Interestingly however, even after lytic infection, a virus strain specific difference was observed.</p

A comparison of 7 Tesla MR spectroscopic imaging and 3 Tesla MR fingerprinting for tumor localization in glioma patients

This paper investigates the correlation between magnetic resonance spectroscopic imaging (MRSI) and magnetic resonance fingerprinting (MRF) in glioma patients by comparing neuro-oncological markers obtained from MRSI to T1/T2 maps from MRF. Data from 12 consenting patients with gliomas were analyzed by defining hotspots for T1, T2 and various metabolic ratios, and comparing them using S{\o}rensen-Dice Similarity Coefficients (DSCs) and the distances between their centers of intensity (COIDs). Median DSCs between MRF and the tumor segmentation were 0.73 (T1) and 0.79 (T2). The DSCs between MRSI and MRF were highest for Gln/tNAA (T1: 0.75, T2: 0.80, tumor: 0.78), followed by Gly/tNAA (T1: 0.57, T2: 0.62, tumor: 0.54) and tCho/tNAA (T1: 0.61, T2: 0.58, tumor: 0.45). The median values in the tumor hotspot were T1=1724 ms, T2=86 ms, Gln/tNAA=0.61, Gly/tNAA=0.28, Ins/tNAA=1.15, and tCho/tNAA=0.48, and, in the peritumoral region, were T1=1756 ms, T2=102ms, Gln/tNAA=0.38, Gly/tNAA=0.20, Ins/tNAA=1.06, and tCho/tNAA=0.38, and, in the NAWM, were T1=950 ms, T2=43 ms, Gln/tNAA=0.16, Gly/tNAA=0.07, Ins/tNAA=0.54, and tCho/tNAA=0.20. The results of this study constitute the first comparison of 7T MRSI and 3T MRF, showing a good correspondence between these methods.Comment: Includes 3 tables, 6 figures, 3 supplementary tables, and 4 supplementary figure

Group recruitment in a thermophilic desert ant, Ocymyrmex robustior

Thermophilic desert ants—Cataglyphis, Ocymyrmex, and Melophorus species inhabiting the arid zones of the Palaearctic region, southern Africa and central Australia, respectively—are solitary foragers, which have been considered to lack any kind of chemical recruitment. Here we show that besides mainly employing the solitary mode of food retrieval Ocymyrmex robustior regularly exhibits group recruitment to food patches that cannot be exploited individually. Running at high speed to recruitment sites that may be more than 60m apart from the nest a leading ant, the recruiter, is followed by a loose and often quite dispersed group of usually 2-7 recruits, which often overtake the leader, or may lose contact, fall back and return to the nest. As video recordings show the leader, while continually keeping her gaster in a downward position, intermittently touches the surface of the ground with the tip of the gaster most likely depositing a volatile pheromone signal. These recruitment events occur during the entire diurnal activity period of the Ocymyrmex foragers, that is, even at surface temperatures of more than 60°C. They may provide promising experimental paradigms for studying the interplay of orientation by chemical signals and path integration as well as other visual guidance routine

The impact of diacetylmorphine on hypothalamic-pituitary-adrenal axis activity and heroin craving in heroin dependence

Background/Aim: Heroin dependence is a chronic relapsing disorder characterized by the compulsion to seek and use heroin. Stress and craving are seen as key factors for heroin use. Moreover, altered hypothalamic-pituitary-adrenal (HPA) axis function has been frequently reported. However, the acute effects of diacetylmorphine (DAM) on HPA axis activity and craving have not been investigated in a controlled study. The present randomized controlled study examined whether DAM administration differs from placebo (saline) administration with regard to HPA axis response and heroin craving. Methods: In a crossover experiment, 28 DAM-maintained heroin-dependent patients were first injected with DAM and then saline, or the converse. Plasma adrenocorticotropic hormone (ACTH) and cortisol in saliva and serum were measured at baseline and 20 and 60 min after both injections. Heroin craving was measured at baseline and 60 min after both injections, by means of the Heroin Craving Questionnaire. Results: Compared to saline, DAM administration induced a significant decrease in plasma ACTH (p &lt; 0.01), serum cortisol (p &lt; 0.0001) and saliva cortisol (p &lt; 0.01), as well as in craving (p &lt; 0.0001), over time. Conclusion: Since acute DAM administration suppresses the stress response, DAM-assisted treatment may be an effective alternative to methadone maintenance in stress-sensitive heroin-dependent patients

Rashba precession in quantum wires with interaction

Rashba precession of spins moving along a one-dimensional quantum channel is calculated, accounting for Coulomb interactions. The Tomonaga--Luttinger model is formulated in the presence of spin-orbit scattering and solved by Bosonization. Increasing interaction strength at decreasing carrier density is found to {\sl enhance} spin precession and the nominal Rashba parameter due to the decreasing spin velocity compared with the Fermi velocity. This result can elucidate the observed pronounced changes of the spin splitting on applied gate voltages which are estimated to influence the interface electric field in heterostructures only little.Comment: now replaced by published versio

In vitro interaction network of a synthetic gut bacterial community

A key challenge in microbiome research is to predict the functionality of microbial communities based on community membership and (meta)-genomic data. As central microbiota functions are determined by bacterial community networks, it is important to gain insight into the principles that govern bacteria-bacteria interactions. Here, we focused on the growth and metabolic interactions of the Oligo-Mouse-Microbiota (OMM12) synthetic bacterial community, which is increasingly used as a model system in gut microbiome research. Using a bottom-up approach, we uncovered the directionality of strain-strain interactions in mono- and pairwise co-culture experiments as well as in community batch culture. Metabolic network reconstruction in combination with metabolomics analysis of bacterial culture supernatants provided insights into the metabolic potential and activity of the individual community members. Thereby, we could show that the OMM12 interaction network is shaped by both exploitative and interference competition in vitro in nutrient-rich culture media and demonstrate how community structure can be shifted by changing the nutritional environment. In particular, Enterococcus faecalis KB1 was identified as an important driver of community composition by affecting the abundance of several other consortium members in vitro. As a result, this study gives fundamental insight into key drivers and mechanistic basis of the OMM12 interaction network in vitro, which serves as a knowledge base for future mechanistic in vivo studies

Precision Oncology in Pancreatic Cancer: Experiences and Challenges of the CCCMunichLMU Molecular Tumor Board

Background!#!In pancreatic cancer, systemic treatment options in addition to chemotherapy remain scarce, and so far only a small proportion of patients benefit from targeted therapies.!##!Objective!#!The patients with pancreatic cancer discussed in the CCCMunich!##!Methods!#!Patients with pancreatic cancer who received comprehensive genomic profiling and were discussed in the interdisciplinary Molecular Tumor Board between May 2017 and July 2022 were included. These patients' medical charts, comprehensive genomic profiling results, and Molecular Tumor Board recommendations were analyzed in this retrospective cohort study.!##!Results!#!Molecular profiles of 165 patients with pancreatic cancer were discussed in the Molecular Tumor Board. In the 149 cases where comprehensive genomic profiling was successful, KRAS mutations were detected in 87.9%, TP53 in 53.0%, and CDKN2A in 14.1%. 33.3% of KRAS wild-type patients harbored targetable mutations, while these were only found in 19.1% of patients with the KRAS mutation; however, this difference was not statistically significant. 63.8% of patients with successful testing received a targeted treatment recommendation by the Molecular Tumor Board; however, only 3.2% of these were put into practice. Compared to a historic cohort of patients with pancreatic cancer with synchronous metastatic disease diagnosed between 2010 and 2017, the patients from the pancreatic cancer cohort with synchronous metastatic disease had a longer survival.!##!Conclusions!#!This single-center experience emphasizes the challenges of targeted treatment in pancreatic cancer. Very few patients ultimately received the recommended therapies, highlighting the need for more and better targeted treatment options in pancreatic cancer, early comprehensive genomic profiling to allow sufficient time to put Molecular Tumor Board recommendations into practice, and close cooperation with clinical trial units to give patients access to otherwise not available targeted treatments