@article{SkryabinKartashovEgorovetal.2017, author = {Skryabin, D.V. and Kartashov, Y.V. and Egorov, O.A. and Sich, M. and Chana, J.K. and Tapia Rodriguez, L.E. and Walker, P.M. and Clarke, E. and Royall, B. and Skolnick, M.S. and Krizhanovskii, D.N.}, title = {Backward Cherenkov radiation emitted by polariton solitons in a microcavity wire}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, doi = {10.1038/s41467-017-01751-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173046}, year = {2017}, abstract = {Exciton-polaritons in semiconductor microcavities form a highly nonlinear platform to study a variety of effects interfacing optical, condensed matter, quantum and statistical physics. We show that the complex polariton patterns generated by picosecond pulses in microcavity wire waveguides can be understood as the Cherenkov radiation emitted by bright polariton solitons, which is enabled by the unique microcavity polariton dispersion, which has momentum intervals with positive and negative group velocities. Unlike in optical fibres and semiconductor waveguides, we observe that the microcavity wire Cherenkov radiation is predominantly emitted with negative group velocity and therefore propagates backwards relative to the propagation direction of the emitting soliton. We have developed a theory of the microcavity wire polariton solitons and of their Cherenkov radiation and conducted a series of experiments, where we have measured polariton-soliton pulse compression, pulse breaking and emission of the backward Cherenkov radiation.}, language = {en} } @article{RiveroSeltenSichetal.2015, author = {Rivero, O and Selten, MM and Sich, S and Popp, S and Bacmeister, L and Amendola, E and Negwer, M and Schubert, D and Proft, F and Kiser, D and Schmitt, AG and Gross, C and Kolk, SM and Strekalova, T and van den Hove, D and Resink, TJ and Kasir, N Nadif and Lesch, KP}, title = {Cadherin-13, a risk gene for ADHD and comorbid disorders, impacts GABAergic function in hippocampus and cognition}, series = {Translational Psychiatry}, volume = {5}, journal = {Translational Psychiatry}, number = {e655}, doi = {10.1038/tp.2015.152}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145218}, year = {2015}, abstract = {Cadherin-13 (CDH13), a unique glycosylphosphatidylinositol-anchored member of the cadherin family of cell adhesion molecules, has been identified as a risk gene for attention-deficit/hyperactivity disorder (ADHD) and various comorbid neurodevelopmental and psychiatric conditions, including depression, substance abuse, autism spectrum disorder and violent behavior, while the mechanism whereby CDH13 dysfunction influences pathogenesis of neuropsychiatric disorders remains elusive. Here we explored the potential role of CDH13 in the inhibitory modulation of brain activity by investigating synaptic function of GABAergic interneurons. Cellular and subcellular distribution of CDH13 was analyzed in the murine hippocampus and a mouse model with a targeted inactivation of Cdh13 was generated to evaluate how CDH13 modulates synaptic activity of hippocampal interneurons and behavioral domains related to psychopathologic (endo) phenotypes. We show that CDH13 expression in the cornu ammonis (CA) region of the hippocampus is confined to distinct classes of interneurons. Specifically, CDH13 is expressed by numerous parvalbumin and somatostatin-expressing interneurons located in the stratum oriens, where it localizes to both the soma and the presynaptic compartment. Cdh13\(^{-/-}\) mice show an increase in basal inhibitory, but not excitatory, synaptic transmission in CA1 pyramidal neurons. Associated with these alterations in hippocampal function, Cdh13\(^{-/-}\) mice display deficits in learning and memory. Taken together, our results indicate that CDH13 is a negative regulator of inhibitory synapses in the hippocampus, and provide insights into how CDH13 dysfunction may contribute to the excitatory/inhibitory imbalance observed in neurodevelopmental disorders, such as ADHD and autism.}, language = {en} }