Synaptic Remodeling Depends on Signaling between Serotonin Receptors and the Extracellular Matrix

Rewiring of synaptic circuitry pertinent to memory formation has been associated with morphological changes in dendritic spines and with extracellular matrix (ECM) remodeling. Here, we mechanistically link these processes by uncovering a signaling pathway involving the serotonin 5-HT7 receptor (5-HT7R), matrix metalloproteinase 9 (MMP-9), the hyaluronan receptor CD44, and the small GTPase Cdc42. We highlight a physical interaction between 5-HT7R and CD44 (identified as an MMP-9 substrate in neurons) and find that 5-HT7R stimulation increases local MMP-9 activity, triggering dendritic spine remodeling, synaptic pruning, and impairment of long-term potentiation (LTP). The underlying molecular machinery involves 5-HT7R-mediated activation of MMP-9, which leads to CD44 cleavage followed by Cdc42 activation. One important physiological consequence of this interaction includes an increase in neuronal outgrowth and elongation of dendritic spines, which might have a positive effect on complex neuronal processes (e.g., reversal learning and neuronal regeneration)

Fly on the wall-attachment structures in lower Diptera

Pretarsal attachment structures of representatives of themegadiverseDiptera are examined and documented, mainly using scanning electron microscopy. The focus is on the basal ‘nematoceran’ lineages. The diversity in structures is much higher than suggested by brief summarizing accounts in earlier studies. Both hairy and smooth attachment structures occur. A well-developed, pad-like empodium with its ventral surface covered with adhesive hairs is arguably a groundplan feature of Diptera. Very often this pad is combined with the presence of hairy pulvilli. However, smooth pulvilli occur in two of the examined groups. A smooth arolium is present in Tipulomorpha and likely an autapomorphy of this clade, suggesting that it was acquired secondarily. Evolutionary transformations are interpreted based on recently published dipteran phylogenies

The skeletomuscular system of the larva of Drosophila melanogaster (Drosophilidae, Diptera) - A contribution to the morphology of a model organism

10.1016/j.asd.2012.09.005Arthropod Structure and Development42147-68ASDR

Lese-Rechtschreib-Störung. Die Bedeutung der phonologischen Informationsverarbeitung für den Schriftspracherwerb

Ptok M, Berendes K, Gottal S, Grabherr B, Schneeberg J, Wittler M. Lese-Rechtschreib-Störung. Die Bedeutung der phonologischen Informationsverarbeitung für den Schriftspracherwerb. HNO. 2007;55(9):737-748

Phonologische Verarbeitung

Ptok M, Berendes K, Gottal S, Grabherr B, Schneeberg J, Wittler M. Phonologische Verarbeitung. Monatsschrift Kinderheilkunde. 2008;156(9):860-866