| Title: | Time of day changes in cyclic nucleotides are modified via octopamine and pheromone in antennae of the Madeira cockroach |
| Author(s): | Schendzielorz T; Peters W; Boekhoff I; Stengl M; |
| Address: | "Department of Biology, Animal Physiology, University of Kassel, Kassel, Germany" |
| ISSN/ISBN: | 1552-4531 (Electronic) 0748-7304 (Linking) |
| Abstract: | "The cockroach Rhyparobia (Leucophaea) maderae expresses a circadian rhythm in pheromone-dependent mating activity that peaks at the late day/early night. In contrast, the circadian rhythm in olfactory sensitivity of the Madeira cockroach is at its minimum during this time. Until now, the reasons for this obvious discrepancy in phase were not understood. Previously, it was shown that cyclic nucleotides modulate olfactory sensitivity in a zeitgeber time (ZT)-dependent manner. In moths' olfactory receptor neurons, adapting pheromone concentrations elevate cGMP levels, which decrease pheromone sensitivity. In contrast, cAMP elevations sensitized pheromone responses. Thus, with immunoassay kits, it was determined whether cAMP and cGMP baseline levels vary in a ZT-dependent manner in antennal lysates of female R. maderae, revealing underlying circadian rhythms in olfactory sensitivity. Furthermore, it was examined whether adapting pheromone exposure elevates cGMP levels in cockroach antennae, possibly overshadowing underlying circadian rhythms in sensitivity via sensory adaptation. It was shown for the first time that cAMP and cGMP baseline levels oscillate in antiphase in a ZT-dependent manner in an insect's antenna, with the maximum in cAMP concentrations coinciding with maximal mating activity during the late day. Moreover, the cAMP baseline level oscillation expressed a circadian rhythm since it persisted under constant darkness in contrast to cGMP baseline levels. Furthermore, while excess exposure to male pheromones increased cGMP and decreased cAMP baseline levels, the stress hormone octopamine increased adenylyl cyclase activity at all ZTs tested. Therefore, it is suggested that cyclic nucleotide-dependent modulation of olfactory sensitivity due to olfactory overstimulation and stress could be responsible for previously measured phase discrepancies between rhythms in mating behavior and pheromone sensitivity" |
| Keywords: | "Adaptation, Physiological Animals Arthropod Antennae/*physiology Circadian Rhythm/*physiology Cockroaches/physiology Cyclic AMP/*metabolism Cyclic GMP/*metabolism Female Male Octopamine/*physiology Olfactory Receptor Neurons/drug effects/*physiology Phero;" |
| Notes: | "MedlineSchendzielorz, Thomas Peters, Wladimir Boekhoff, Ingrid Stengl, Monika eng 2012/09/27 J Biol Rhythms. 2012 Oct; 27(5):388-97. doi: 10.1177/0748730412456265" |
