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J Neurophysiol

Title:		Cyclic nucleotide-activated currents in cultured olfactory receptor neurons of the hawkmoth Manduca sexta
Author(s):		Krannich S; Stengl M;
Address:		"Biology, Animal Physiology, Philipps-University of Marburg, Karl-von-Frisch-Strabetae, Marburg D-35032, Germany"
Journal Title:		J Neurophysiol
Year:		2008
Volume:		20080806
Issue:		5
Page Number:		2866 - 2877
DOI:		10.1152/jn.01400.2007
ISSN/ISBN:		0022-3077 (Print) 0022-3077 (Linking)
Abstract:		"Moth pheromones cause rises in intracellular Ca(2+) concentrations that activate Ca(2+)-dependent cation channels in antennal olfactory receptor neurons. In addition, mechanisms of adaptation and sensitization depend on changes in cyclic nucleotide concentrations. Here, cyclic nucleotide-activated currents in cultured olfactory receptor neurons of the moth Manduca sexta are described, which share properties with currents through vertebrate cyclic nucleotide-gated channels. The cyclic nucleotide-activated currents of M. sexta carried Ca(2+) and monovalent cations. They were directly activated by cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), modulated by Ca(2+)/calmodulin, and inhibited by lanthanum. M. sexta cyclic nucleotide-activated currents developed in an all-or-none manner, which suggests that the underlying channels are coupled and act coordinately. At least one cAMP- and two cGMP-activated nonselective cation currents could be distinguished. Compared with the cAMP-activated current, both cGMP-activated currents appeared to conduct more Ca(2+) and showed a stronger down-regulation by Ca(2+)/calmodulin-dependent negative feedback. Furthermore, both cGMP-activated currents differed in their Ca(2+)-dependent inhibition. Thus M. sexta olfactory receptor neurons, like vertebrate sensory neurons, appear to express nonselective cyclic nucleotide-activated cation channels with different subunit compositions. Besides the nonselective cyclic nucleotide-activated cation currents, olfactory receptor neurons express a cAMP-dependent current. This current resembled a protein kinase-modulated low-voltage-activated Ca(2+) current"
Keywords:		"8-Bromo Cyclic Adenosine Monophosphate/pharmacology Action Potentials/drug effects/physiology/radiation effects Animals Calcium/metabolism Cells, Cultured Cyclic GMP/analogs & derivatives/pharmacology Dose-Response Relationship, Radiation Electric Stimula;"
Notes:		"MedlineKrannich, Steffi Stengl, Monika eng Research Support, Non-U.S. Gov't 2008/08/08 J Neurophysiol. 2008 Nov; 100(5):2866-77. doi: 10.1152/jn.01400.2007. Epub 2008 Aug 6"