Direct effects of carbachol on membrane potential and ion activities in leech glial cells.
Ion-selective double-barreled microelectrodes were used to measure the activities of intracellular K+ and Na+ (aKi, aNai) and the membrane potential (Em) in neuropile glial cells as well as extracellular K+ (aKe) in the neuropile of segmental ganglia in the leech, Hirudo medicinalis. Bath-application of carbachol resulted in a prominent membrane depolarization. This depolarization was accompanied by transient increases of aNai and aKe, whereas aKi decreased. It is suggested that the carbachol-induced depolarization and the underlying ion activity changes are due to activation of an acetylcholine receptor-coupled cation channel in the membrane of the neuropile glial cells.
Ballanyi
K
K
Institut für Zoologie, Lehrstuhl Neurobiologie, Universität Düsseldorf, Federal Republic of Germany.
Schlue
W R
WR
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D005724:Ganglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007865:Leeches / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000502:physiology*; D012964:Sodium / Q000502:physiology*
D002217:Carbachol; D012964:Sodium; D011188:Potassium