@misc{VossBlenauWalzetal.2009,
  author    = {Voss, Martin and Blenau, Wolfgang and Walz, Bernd and Baumann, Otto},
  title     = {V-ATPase deactivation in blowfly salivary glands is mediated by protein phosphatase 2C},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44360},
  year      = {2009},
  abstract  = {The activity of vacuolar H+-ATPase (V-ATPase) in the apical membrane of blowfly (Calliphora vicina) salivary glands is regulated by the neurohormone serotonin (5-HT). 5-HT induces, via protein kinase A, the phosphorylation of V-ATPase subunit C and the assembly of V-ATPase holoenzymes. The protein phosphatase responsible for the dephosphorylation of subunit C and V-ATPase inactivation is not as yet known. We show here that inhibitors of protein phosphatases PP1 and PP2A (tautomycin, ocadaic acid) and PP2B (cyclosporin A, FK-506) do not prevent V-ATPase deactivation and dephosphorylation of subunit C. A decrease in the intracellular Mg2+ level caused by loading secretory cells with EDTA-AM leads to the activation of proton pumping in the absence of 5-HT, prolongs the 5-HT-induced response in proton pumping, and inhibits the dephosphorylation of subunit C. Thus, the deactivation of V-ATPase is most probably mediated by a protein phosphatase that is insensitive to okadaic acid and that requires Mg2+, namely, a member of the PP2C protein family. By molecular biological techniques, we demonstrate the expression of at least two PP2C protein family members in blowfly salivary glands. © 2009 Wiley Periodicals, Inc.},
  language  = {en}
}
@article{FrenchSimcockRolkeetal.2014,
  author    = {French, Alice S. and Simcock, Kerry L. and Rolke, Daniel and Gartside, Sarah E. and Blenau, Wolfgang and Wright, Geraldine A.},
  title     = {The role of serotonin in feeding and gut contractions in the honeybee},
  series = {Journal of insect physiology},
  volume    = {61},
  journal   = {Journal of insect physiology},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0022-1910},
  doi       = {10.1016/j.jinsphys.2013.12.005},
  pages     = {8 -- 15},
  year      = {2014},
  language  = {en}
}
@article{VerlindenVleugelsMarchaletal.2010,
  author    = {Verlinden, Heleen and Vleugels, Rut and Marchal, Elisabeth and Badisco, Liesbeth and Pfl{\"u}ger, Hans-Joachim and Blenau, Wolfgang and Vanden Broeck, Jozef},
  title     = {The role of octopamine in locusts and other arthropods},
  issn      = {0022-1910},
  doi       = {10.1016/j.jinsphys.2010.05.018},
  year      = {2010},
  abstract  = {The biogenic amine octopamine and its biological precursor tyramine are thought to be the invertebrate functional homologues of the vertebrate adrenergic transmitters. Octopamine functions as a neuromodulator, neurotransmitter and neurohormone in insect nervous systems and prompts the whole organism to "dynamic action". A growing number of studies suggest a prominent role for octopamine in modulating multiple physiological and behavioural processes in invertebrates, as for example the phase transition in Schistocerca gregaria. Both octopamine and tyramine exert their effects by binding to specific receptor proteins that belong to the superfamily of G protein-coupled receptors. Since these receptors do not appear to be present in vertebrates, they may present very suitable and specific insecticide and acaricide targets. (C) 2010 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{MargWalzBlenau2004,
  author    = {Marg, S. and Walz, Bernd and Blenau, Wolfgang},
  title     = {The effects of dopamine receptor agonists and antagonists on the secretory rate of cockroach (Periplaneta americana) salivary glands},
  issn      = {0022-1910},
  year      = {2004},
  abstract  = {The acinar salivary glands of the cockroach, Periplaneta americana, are innervated by dopaminergic and serotonergic nerve fibers. Serotonin stimulates the secretion of protein-rich saliva, whereas dopamine causes the production of protein-free saliva. This suggests that dopamine acts selectively on ion-transporting peripheral cells within the acini and the duct cells, and that serotonin acts on the protein-producing central cells of the acini. We have investigated the pharmacology of the dopamine-induced secretory activity of the salivary gland of Periplaneta americana by testing several dopamine receptor agonists and antagonists. The effects of dopamine can be mimicked by the non-selective dopamine receptor agonist 6,7-ADTN and, less effectively, by the vertebrate D1 receptor-selective agonist chloro-APB. The vertebrate D1 receptor-selective agonist SKF 38393 and vertebrate D2 receptor-selective agonist R(-)- TNPA were ineffective. R(+)-Lisuride induces a secretory response with a slower onset and a lower maximal response compared with dopamine-induced secretion. However, lisuride-stimulated glands continue secreting saliva, even after lisuride-washout. Dopamine-induced secretions can be blocked by the vertebrate dopamine receptor antagonists cis(Z)- flupenthixol, chlorpromazine, and S(+)-butaclamol. Our pharmacological data do not unequivocally indicate whether the dopamine receptors on the Periplaneta salivary glands belong to the D1 or D2 subfamily of dopamine receptors, but we can confirm that the pharmacology of invertebrate dopamine receptors is remarkably different from that of their vertebrate counterparts. (C) 2004 Elsevier Ltd. All rights reserved},
  language  = {en}
}
@article{VerlindenVleugelsMarchaletal.2010,
  author    = {Verlinden, Heleen and Vleugels, Rut and Marchal, Elisabeth and Badisco, Liesbeth and Tobback, Julie and Pfl{\"u}ger, Hans-Joachim and Blenau, Wolfgang and Vanden Broeck, Jozef},
  title     = {The cloning, phylogenetic relationship and distribution pattern of two new putative GPCR-type octopamine receptors in the desert locust (Schistocerca gregaria)},
  issn      = {0022-1910},
  doi       = {10.1016/j.jinsphys.2010.03.003},
  year      = {2010},
  abstract  = {The biogenic amine octopamine functions as a neuromodulator, neurotransmitter and neurohormone in insect nervous systems. It plays a prominent role in modulating multiple physiological and behavioural processes in invertebrates. Octopamine exerts its effects by binding to specific receptor proteins that belong to the superfamily of G protein-coupled receptors. We found two partial sequences of putative octopamine receptors in the desert locust Schistocerca gregaria (SgOct alpha R and SgOct beta R) and investigated their transcript levels in males and females of both phases and during the transition between long-term solitarious and gregarious locusts. The transcript levels of SgOctaR are the highest in the central nervous system, whereas those of SgOct beta R are the highest in the flight muscles, followed by the central nervous system. Both SgOct alpha R and SgOct beta R show higher transcript levels in long-term gregarious locusts as compared to solitarious ones. The rise of SgOct beta R transcript levels already appears during the first 4 h of gregarisation, during which also the behavioural changes take place.},
  language  = {en}
}
@article{WalzBaumannKrachetal.2006,
  author    = {Walz, Bernd and Baumann, Otto and Krach, Christian and Baumann, Arnd and Blenau, Wolfgang},
  title     = {The aminergic control of cockroach salivary glands},
  year      = {2006},
  abstract  = {The acinar salivary glands of cockroaches receive a dual innervation from the subesophageal ganglion and the stomatogastric nervous system. Acinar cells are surrounded by a plexus of dopaminergic and serotonergic varicose fibers. In addition, seroton-ergic terminals lie deep in the extracellulor spaces between acinar cells. Excitation-secretion coupling in cockroach salivary glands is stimulated by both dopamine and serotonin. These monoamines cause increases in the intracellular concentrations of cAMP and Ca2+. Stimulation of the glands by serotonin results in the production of a protein-rich saliva, whereas stimulation by dopamine results in saliva that is protein-free. Thus, two elementary secretary processes, namely electrolyte/water secretion and protein secretion, are triggered by different aminergic transmitters. Because of its simplicity and experimental accessibility, cockroach salivary glands have been used extensively as a model system to study the cellular actions of biogenic amines and to examine the pharmacological properties of biogenic amine receptors. In this review, we summarize current knowledge concerning the aminergic control of cockroach salivary glands and discuss our efforts to characterize Periplaneta biogenic amine receptors molecularly},
  language  = {en}
}
@article{ReimThammRolkeetal.2013,
  author    = {Reim, Tina and Thamm, Markus and Rolke, Daniel and Blenau, Wolfgang and Scheiner, Ricarda},
  title     = {Suitability of three common reference genes for quantitative real-time PCR in honey bees},
  series = {Apidologie : a quality journal in bee science},
  volume    = {44},
  journal   = {Apidologie : a quality journal in bee science},
  number    = {3},
  publisher = {Springer},
  address   = {Paris},
  issn      = {0044-8435},
  doi       = {10.1007/s13592-012-0184-3},
  pages     = {342 -- 350},
  year      = {2013},
  abstract  = {Honey bees are important model organisms for neurobiology, because they display a large array of behaviors. To link behavior with individual gene function, quantitative polymerase chain reaction is frequently used. Comparing gene expression of different individuals requires data normalization using adequate reference genes. These should ideally be expressed stably throughout lifetime. Unfortunately, this is frequently not the case. We studied how well three commonly used reference genes are suited for this purpose and measured gene expression in the brains of honey bees differing in age and social role. Although rpl32 is used most frequently, it only remains stable in expression between newly emerged bees, nurse-aged bees, and pollen foragers but shows a peak at the age of 12 days. The genes gapdh and ef1 alpha-f1, in contrast, are expressed stably in the brain throughout all age groups except newly emerged bees. According to stability software, gapdh was expressed most stably, followed by rpl32 and ef1 alpha-f1.},
  language  = {en}
}
@misc{BlenauRotteWitteetal.2009,
  author    = {Blenau, Wolfgang and Rotte, Cathleen and Witte, Jeannine and Baumann, Otto and Walz, Bernd},
  title     = {Source, topography and excitatory effects of GABAergic innervation in cockroach salivary glands},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44353},
  year      = {2009},
  abstract  = {Cockroach salivary glands are innervated by dopaminergic and serotonergic neurons. Both transmitters elicit saliva secretion. We studied the distribution pattern of neurons containing gamma-aminobutyric acid ( GABA) and their physiological role. Immunofluorescence revealed a GABA-immunoreactive axon that originates within the subesophageal ganglion at the salivary neuron 2 (SN2) and this extends within the salivary duct nerve towards the salivary gland. GABA-positive fibers form a network on most acinar lobules and a dense plexus in the interior of a minor fraction of acinar lobules. Co-staining with anti-synapsin revealed that some putative GABAergic terminals seem to make pre-synaptic contacts with GABA-negative release sites. Many putative GABAergic release sites are at some distance from other synapses and at distance from the acinar tissue. Intracellular recordings from isolated salivary glands have revealed that GABA does not affect the basolateral membrane potential of the acinar cells directly. When applied during salivary duct nerve stimulation, GABA enhances the electrical response of the acinar cells and increases the rates of fluid and protein secretion. The effect on electrical cell responses is mimicked by the GABA(B) receptor agonists baclofen and SKF97541, and blocked by the GABAB receptor antagonists CGP52432 and CGP54626. These findings indicate that GABA has a modulatory role in the control of salivation, acting presynaptically on serotonergic and/or dopaminergic neurotransmission.},
  language  = {en}
}
@article{RichterRolkeBlenauetal.2016,
  author    = {Richter, Katharina Natalia and Rolke, Daniel and Blenau, Wolfgang and Baumann, Otto},
  title     = {Secretory cells in honeybee hypopharyngeal gland: polarized organization and age-dependent dynamics of plasma membrane},
  series = {Cell \& tissue research},
  volume    = {366},
  journal   = {Cell \& tissue research},
  publisher = {Springer},
  address   = {New York},
  issn      = {0302-766X},
  doi       = {10.1007/s00441-016-2423-9},
  pages     = {163 -- 174},
  year      = {2016},
  abstract  = {The honeybee hypopharyngeal gland consists in numerous units, each comprising a secretory cell and a canal cell. The secretory cell discharges its products into a convoluted tubular membrane system, the canaliculus, which is surrounded at regular intervals by rings of actin filaments. Using probes for various membrane components, we analyze the organization of the secretory cells relative to the apicobasal configuration of epithelial cells. The canaliculus was defined by labeling with an antibody against phosphorylated ezrin/radixin/moesin (pERM), a marker protein for the apical membrane domain of epithelial cells. Anti-phosphotyrosine visualizes the canalicular system, possibly by staining the microvillar tips. The open end of the canaliculus leads to a region in which the secretory cell is attached to the canal cell by adherens and septate junctions. The remaining plasma membrane stains for Na,K-ATPase and spectrin and represents the basolateral domain. We also used fluorophore-tagged phalloidin, anti-phosphotyrosine and anti-pERM as probes for the canaliculus in order to describe fine-structural changes in the organization of the canalicular system during the adult life cycle. These probes in conjunction with fluorescence microscopy allow the fast and detailed three-dimensional analysis of the canalicular membrane system and its structural changes in a developmental mode or in response to environmental factors.},
  language  = {en}
}
@article{RietdorfBlenauWalz2005,
  author    = {Rietdorf, Katja and Blenau, Wolfgang and Walz, Bernd},
  title     = {Protein secretion in cockroach salivary glands requires an increase in intracellular cAMP and Ca2+ concentrations},
  issn      = {0022-1910},
  year      = {2005},
  abstract  = {The salivary glands in the cockroach Periplaneta americana secrete protein-containing saliva when stimulated by serotonin (5-HT) and protein-free saliva upon dopamine stimulation. In order to obtain information concerning the signalling pathways involved in 5-HT-induced protein secretion, we have determined the protein content of saliva secreted after experimental manipulations that potentially elevate intracellular Ca2+ and cyclic nucleotide concentrations in isolated glands. We have found that 5-HT stimulates the rate of protein secretion in a dose-dependent manner (threshold: 3 x 10(-8) M; EC50 1.5 x 10(-6) M). The maximal rate of 5-HT-induced protein secretion was 2.2 +/- 0.2 mu g/min. Increasing intracellular Ca2+ or cAMP by bath application of ionomycin (5 mu M), db cAMP (10 mM), forskolin (100 mu M) or IBMX (100 mu M), respectively, stimulated protein secretion at significantly lower rates, whereas db cGMP (1 mM) did not activate protein secretion. The high rates and the kinetics of 5-HT-induced protein secretion could only be mimicked by either applying forskolin together with IBMX (with or without ionomycin) or by applying IBMX together with ionomycin. Our measurements suggest that 5-HT-induced protein secretion is mediated by an elevation of [cAMP](i) and that Ca2+ may function as a co-agonist and augment the rate of protein secretion. (c) 2005 Elsevier Ltd. All rights reserved},
  language  = {en}
}