Currents caused by the spontaneous release of quanta of acetylcholine onto chromaffin cells in guinea-pig adrenal medulla.
Membrane potentials were recorded from chromaffin cells in isolated bisected adrenal glands from guinea-pigs. Spontaneous excitatory synaptic potentials (SESPs) were recorded whose frequency was increased following brief (up to 10 s) periods of presynaptic nerve stimulation at 10-30 Hz. The single electrode voltage-clamp method was used to record the currents underlying all but the largest SESPs. Spontaneous excitatory synaptic currents (SESCs) decayed according to a single exponential with a time constant of about 8 ms at 30 degrees C. Thus the neuronal nicotinic receptor-channels giving rise to SESCs in chromaffin cells are probably very similar to those that are opened by quanta of acetylcholine in sympathetic ganglion cells.
Holman
M E
ME
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Tonta
M A
MA
Coleman
H A
HA
Parkington
H C
HC
D000109:Acetylcholine / Q000378:metabolism*; D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D002838:Chromaffin System / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D051379:Mice; D018408:Patch-Clamp Techniques; D013569:Synapses / Q000378:metabolism
D007473:Ion Channels; D000109:Acetylcholine