TY - JOUR
T1 - Effects of hydrostatic pressure on sensory discharge in frog semicircular canals
AU - Zucca, G.
AU - Botta, L.
AU - Mira, E.
AU - Manfrin, M.
AU - Poletti, A.
AU - Buizza, A.
AU - Valli, P.
PY - 1991
Y1 - 1991
N2 - The effects of endolymphatic and perilymphatic pressure changes on resting and mechanically evoked responses were studied in isolated posterior semicircular canals of the frog. the results demonstrated that ampullar receptors are extremely sensitive to hydrostatic pressure changes (0.25 mm H20 were sufficient to produce distinct changes), being inhibited by endolymphatic pressure increases and facilitated by perilymphatic ones. Intracellular recordings from single afferent axons showed that the effects of hydrostatic pressure result from a modified transmitter release from the synaptic po'e of the hair cells. Unlike resting activity, mechanically evoked activity was always depressed in the presence of a hydrostatic pressure. This indicates that the sensitivity of ampullar receptors to mechanical stimuli, i.e. the gain of the conversion process, is maximal when no pressure is present between the inner and the outer fluid. the possible action of hydrostatic pressure on vestibular receptors is discussed.
AB - The effects of endolymphatic and perilymphatic pressure changes on resting and mechanically evoked responses were studied in isolated posterior semicircular canals of the frog. the results demonstrated that ampullar receptors are extremely sensitive to hydrostatic pressure changes (0.25 mm H20 were sufficient to produce distinct changes), being inhibited by endolymphatic pressure increases and facilitated by perilymphatic ones. Intracellular recordings from single afferent axons showed that the effects of hydrostatic pressure result from a modified transmitter release from the synaptic po'e of the hair cells. Unlike resting activity, mechanically evoked activity was always depressed in the presence of a hydrostatic pressure. This indicates that the sensitivity of ampullar receptors to mechanical stimuli, i.e. the gain of the conversion process, is maximal when no pressure is present between the inner and the outer fluid. the possible action of hydrostatic pressure on vestibular receptors is discussed.
KW - Inner ear fluid pressures
KW - Semicircular canals
KW - Vestibular afferent activity
UR - http://www.scopus.com/inward/record.url?scp=0026005971&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026005971&partnerID=8YFLogxK
U2 - 10.3109/00016489109138417
DO - 10.3109/00016489109138417
M3 - Article
C2 - 1759566
AN - SCOPUS:0026005971
VL - 111
SP - 820
EP - 826
JO - Acta Oto-Laryngologica
JF - Acta Oto-Laryngologica
SN - 0001-6489
IS - 3
ER -