TY  - GEN
A1  - Blenau, Wolfgang
A1  - Rotte, Cathleen
A1  - Witte, Jeannine
A1  - Baumann, Otto
A1  - Walz, Bernd
T1  - Source, topography and excitatory effects of GABAergic innervation in cockroach salivary glands
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 111 
KW  - GABA
KW  - salivary gland
KW  - innervation
KW  - cockroach
KW  - Periplaneta americana
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44353
ER  - 
TY  - JOUR
A1  - Blankenburg, Stefanie
A1  - Balfanz, Sabine
A1  - Hayashi, Y.
A1  - Shigenobu, S.
A1  - Miura, T.
A1  - Baumann, Otto
A1  - Baumann, Arnd
A1  - Blenau, Wolfgang
T1  - Cockroach GABA(B) receptor subtypes: Molecular characterization, pharmacological properties and tissue distribution
JF  - Neuropharmacology
N2  - gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the central nervous system (CNS). Its effects are mediated by either ionotropic GABA(A) receptors or metabotropic GABA(B) receptors. GABA(B) receptors regulate, via Gi/o, G-proteins, ion channels, and adenylyl cyclases. In humans, GABA(B) receptor subtypes are involved in the etiology of neurologic and psychiatric disorders. In arthropods, however, these members of the G-protein-coupled receptor family are only inadequately characterized. Interestingly, physiological data have revealed important functions of GABA(B) receptors in the American cockroach, Periplaneta americana. We have cloned cDNAs coding for putative GABA(B) receptor subtypes 1 and 2 of P. americana (PeaGB1 and PeaGB2). When both receptor proteins are co-expressed in mammalian cells, activation of the receptor heteromer with GABA leads to a dose-dependent decrease in cAMP production. The pharmacological profile differs from that of mammalian and Drosophila GABA(B) receptors. Western blot analyses with polyclonal antibodies have revealed the expression of PeaGB1 and PeaGB2 in the CNS of the American cockroach. In addition to the widespread distribution in the brain, PeaGB1 is expressed in salivary glands and male accessory glands. Notably, PeaGB1-like immunoreactivity has been detected in the GABAergic salivary neuron 2, suggesting that GABA(B) receptors act as autoreceptors in this neuron.
KW  - GABA(B) receptor
KW  - G-protein-coupled receptor
KW  - Periplaneta americana
KW  - Central nervous system
KW  - Adenylyl cyclase
KW  - Salivary gland
Y1  - 2015
U6  - https://doi.org/10.1016/j.neuropharm.2014.08.022
SN  - 0028-3908
SN  - 1873-7064
VL  - 88
SP  - 134
EP  - 144
PB  - Elsevier
CY  - Oxford
ER  -