Modulation of Drosophila heartbeat by neurotransmitters.
The heart of Drosophila melanogaster is a simple muscular tube with a posterior pulsatile portion and a thoracic-cranial vessel. The pacemaker, located caudally, is myogenic. Its rate of firing is modulated by neurotransmitters. Serotonin, octopamine, norepinephrine, dopamine, and acetylcholine accelerate the heart, in that order of potency. Dihydroxyphenylalanine, gamma-aminobutyric acid, glutamate, and glycine have no effect. Generally, the regularity of the heartbeat is not adversely affected by treatment with any of these neurotransmitters. We show here that amnesiac, a neurological mutation, and Dihydroxyphenylalanine decarboxylasetemperature sensitive, a mutation that interferes with synthesis of dopamine, norepinephrine, and serotonin, result in slower heart rate and reduced regularity across a normal range of temperatures for these flies. Dopamine-N-acetyltransferase, which is on the catabolic route to dopamine, serotonin, and octopamine, has no effect. hypoactiveC reduces the rate of the heart, but its mechanism of action is unknown.
Johnson
E
E
Department of Zoology, University of Maine, Orono 04469, USA.
Ringo
J
J
Dowse
H
H
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D004296:Dopa Decarboxylase / Q000235:genetics; D004298:Dopamine / Q000494:pharmacology; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D009154:Mutation; D018377:Neurotransmitter Agents / Q000494:pharmacology* / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D009655:Octopamine / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D013696:Temperature
D018377:Neurotransmitter Agents; D009655:Octopamine; D012701:Serotonin; D000242:Cyclic AMP; D004296:Dopa Decarboxylase; D000109:Acetylcholine; D004298:Dopamine; D009638:Norepinephrine