title: Evidence for a role of GABA and Mas-allatotropin in photic entrainment of the circadian clock of the cockroach Leucophaea maderae.
abstract: Accumulating evidence suggests that the accessory medulla is the location of the circadian pacemaker in the fruit fly Drosophila melanogaster and the cockroach Leucophaea maderae. gamma-Aminobutyric acid (GABA) and Mas-allatotropin are two putative neurotransmitters, in the accessory medulla in the cockroach Leucophaea maderae. Neurons immunoreactive to the neuropeptide Mas-allatotropin are local neurons with arborizations in the noduli of the accessory medulla, while GABA-immunoreactive neurons connect the noduli of the accessory medulla to the medulla and to the lamina via processes in the distal tract. Injections of GABA and Mas-allatotropin into the vicinity of the accessory medulla resulted in stable phase-dependent resetting of the circadian locomotor activity of the cockroach. The resulting phase response curves closely matched light-dependent phase response curves, suggesting that both substances play a role in circuits relaying photic information from circadian photoreceptors to the central pacemaker.
authors.affiliation: Institut für Zoologie/Biologie I, Universität Regensburg, 93040 Regensburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Petri
authors.forename: Uwe
authors.initials: U
authors.lastname: Homberg
authors.forename: Rudolf
authors.initials: R
authors.lastname: Loesel
authors.forename: Monika
authors.initials: M
authors.lastname: Stengl
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects; D003058:Cockroaches / Q000187:drug effects / Q000502:physiology*; D004331:Drosophila melanogaster / Q000502:physiology; D007267:Injections; D007301:Insect Hormones / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D010775:Photic Stimulation; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*
chemical_list: D007301:Insect Hormones; D009479:Neuropeptides; D005680:gamma-Aminobutyric Acid; C050669:allatotropin