Dual muscarinic and nicotinic action on a motor program in Drosophila.
The effect of cholinergic agonists and antagonists on the central pattern generator of the pharyngeal muscles has been studied in third instar larvae of Drosophila. The pharyngeal muscles are a group of rhythmically active fibers involved in feeding. Bath application of the cholinergic agonists carbachol, muscarine, pilocarpine, and acetylcholine (ACh) to a semiintact preparation including the pharyngeal muscles and the central nervous system (CNS), initiated long-lasting endogenous-like bursting activity in the muscles. The muscarinic antagonists, atropine and scopolamine, blocked these responses as well as endogenous activity. Perfusion with nicotine elicited a short, tonic response that was marginally blocked by mecamylamine but not by curare, alpha-bungarotoxin, hexamethonium, or the muscarinic antagonists. This is the first time that a response to cholinergic drugs has been examined in Drosophila. The pharyngeal muscle preparation may prove to be a valuable system for studying mutations of cholinergic metabolism, receptors, and second messengers.
Department of Biology, University of Iowa, Iowa City 52242.
M G
MG
Gorczyca
V
V
Budnik
K
K
White
C F
CF
Wu
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004330:Drosophila / Q000502:physiology*; D004594:Electrophysiology; D005731:Ganglionic Stimulants / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000502:physiology; D009538:Nicotine / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000187:drug effects; D010276:Parasympatholytics / Q000494:pharmacology*; D010277:Parasympathomimetics / Q000494:pharmacology*; D010609:Pharyngeal Muscles / Q000033:anatomy & histology / Q000187:drug effects* / Q000294:innervation
D005731:Ganglionic Stimulants; D018377:Neurotransmitter Agents; D010276:Parasympatholytics; D010277:Parasympathomimetics; D009538:Nicotine; D000109:Acetylcholine