Sensory adaptation in frog vestibular organs.
Adaptation, i.e., the decrease with time in sensory units' afferent discharge to a constant stimulus, appears to be a common feature of the receptors belonging to acoustico-lateralis system: However, the mechanisms underlying this process are still a matter of debate. The present experiments demonstrate that sensory adaptation to both mechanical and electrical stimuli can be nearly suppressed after perilymphatic ouabain administration. This clearly indicates that the K+ homeostatic mechanisms [Valli et al., (1990) J. Physiol. (London) 430, 585-594] which control the K+ concentration gradient at both ends of vestibular hair cells play a predominant role in this process. The possible importance of different K+-dependent mechanisms in hair cell adaptation is discussed.
Zucca
G
G
Institute of General Physiology, University of Pavia, Italy.
Botta
L
L
Milesi
V
V
Valli
P
P
D000222:Adaptation, Physiological; D000818:Animals; D001001:Anura; D004558:Electric Stimulation; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000502:physiology*; D010042:Ouabain / Q000494:pharmacology*; D010498:Perilymph / Q000187:drug effects; D011188:Potassium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium