Stretch activation of the Aplysia S-channel.
The S-channel, a receptor-mediated K+ channel of Aplysia sensory neurons which functions in neuromodulation, bears a strong resemblance to the ubiquitous stretch-activated channels of snail neurons. Snail neuron stretch channels are stretch sensitive only in the patch, not at the macroscopic level, a situation which leaves open the question of their physiological role. If S-channels resemble snail stretch channels because both belong to the same general class of channels, the S-channel, too, should display stretch sensitivity in the patch. We show, using single-channel recording, that the S-channel can be activated by stretch. Furthermore, we show that Aplysia neurons in general have stretch-activated K+ channels. We suggest that the stretch-sensitive K+ channels of molluscan neurons and other preparations (e.g., Drosophila muscle, snail heart) are S-like channels, i.e., receptor-mediated channels which adventitiously exhibit mechanosensitivity in the patch.
Vandorpe
D H
DH
Department of Biology, University of Ottawa, Ontario, Canada.
Morris
C E
CE
D000005:Abdomen / Q000294:innervation; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D019835:FMRFamide; D005724:Ganglia / Q000502:physiology; D007424:Intracellular Fluid / Q000502:physiology; D007447:Invertebrate Hormones / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000502:physiology
D007447:Invertebrate Hormones; D009479:Neuropeptides; D015221:Potassium Channels; D012701:Serotonin; D019835:FMRFamide; D002118:Calcium