Open AccessBlockage of One Class of Potassium Channel Alters the Effectiveness of Halothane in a Brain Circuit of Drosophila
Author(s) -
Asikiya Walcourt,
Robert L. Scott,
Howard A. Nash
Publication year - 2001
Publication title -
anesthesia and analgesia/anesthesia and analgesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.404
H-Index - 201
eISSN - 1526-7598
pISSN - 0003-2999
DOI - 10.1097/00000539-200102000-00047
Subject(s) - medicine , halothane , potassium channel , class (philosophy) , drosophila (subgenus) , anesthesia , potassium , neuroscience , pharmacology , toxicology , genetics , artificial intelligence , gene , chemistry , organic chemistry , computer science , biology
At concentrations comparable to those used in the clinic, halothane has profound effects on a neuronal pathway devoted to the escape reflex of the fruit fly, Drosophila melanogaster. We studied the influence of the potassium channel that is encoded by the Shaker gene on the halothane sensitivity of this circuit. Shaker channels were specifically inactivated either by genetic means, using strains with two different severe Shaker mutations, or by pharmacologic means, using ingestion of millimolar concentrations of 4-aminopyridine. In all cases, halothane potency decreased substantially. To ensure that the genetic alteration was specific, both mutations were studied as stocks that had been repeatedly backcrossed to a control strain. The specificity of the pharmacologic inhibition was demonstrated by the fact that 4-aminopyridine had no effect on halothane potency in a Shaker mutant. Quantitative differences in the effects of channel inhibition between males and females suggested a sexual dimorphism in the functional brain anatomy of the reflex circuit.