Temperature dependency of cupular mechanics and hair cell frequency selectivity in the fish canal lateral line organ

2000 ◽  
Vol 186 (10) ◽  
pp. 949-956 ◽  
Author(s):  
J. Esther C. Wiersinga-Post ◽  
Sietse M. van Netten
1962 ◽  
Vol 34 (5) ◽  
pp. 733-733
Author(s):  
Willem A. van Bergeijk ◽  
Gerard G. Harris

2005 ◽  
Vol 93 (5) ◽  
pp. 2541-2551 ◽  
Author(s):  
Rosie Dawkins ◽  
Sarah L. Keller ◽  
William F. Sewell

Cholinergic efferent fibers modify hair cell responses to mechanical stimulation. It is hypothesized that calcium entering the hair cell through a nicotinic receptor activates a small-conductance (SK), calcium-activated potassium channel to hyperpolarize the hair cell. The calcium signal may be amplified by calcium-induced calcium release from the synaptic cisternae. Pharmacological tests of these ideas in the intact cochlea have been technically difficult because of the complex and fragile structure of the mammalian inner ear. We turned to the Xenopus laevis lateral line organ, whose simplicity and accessibility make it a model for understanding hair cell organ function in a relatively intact system. Drugs were applied to the inner surface of the skin while monitoring the effects of efferent stimulation on afferent fiber discharge rate. Efferent effects were blocked by antagonists of SK channels including apamin (EC50 = 0.5 μM) and dequalinium (EC50 = 12 μM). The effect of apamin was not enhanced by co-administration of phenylmethylsulfonyl fluoride, a proteolysis inhibitor. Efferent effects were attenuated by ryanodine, an agent that can interfere with calcium-induced calcium release, although relatively high (mM) concentrations of ryanodine were required. Fluorescent cationic styryl dyes, 4-di-2-asp and fm 1–43, blocked efferent effects, although it was not possible to observe specific entry of the dye into the base of hair cells. These pharmacological findings in the Xenopus lateral line organ support the hypothesis that effects of efferent stimulation are mediated by calcium entry through the nicotinic receptor via activation of SK channels and suggest the generality of this mechanism in meditating cholinergic efferent effects.


1980 ◽  
Vol 86 (1) ◽  
pp. 63-77
Author(s):  
ALFONS B. A. KROESE ◽  
JOHAN M. VAN DER ZALM ◽  
JOEP VAN DEN BERCKEN

1. The response of the epidermal lateral-line organ of Xenopus laevis to stimulation was studied by recording extracellular receptor potentials from the hair cells in single neuromasts in isolated preparations. One neuromast was stimulated by local, sinusoidal water movements induced by a glass sphere positioned at a short distance from the neuromast. 2. The amplitudes of the extracellular receptor potentials were proportional to the stimulus amplitude over a range of 20 dB. The phase of the extracellular receptor potentials with respect to water displacement was independent of the stimulus amplitude. 3. With large stimulus amplitude, and stimulus frequencies between 0.5 Hz and 2 Hz, the extracellular receptor potentials, and responses of single afferent nerve fibres, showed a phase lead of 1.2 π radians with respect to water displacement, i.e. they were almost in phase with water acceleration. 4. It is concluded that under conditions of stimulation with small-amplitude water movements, the hair cells respond to sensory hair displacement, whereas under conditions of stimulation with large-amplitude water movements they respond to sensory hair velocity.


1966 ◽  
Vol 29 (3) ◽  
pp. 497-505 ◽  
Author(s):  
Arndt J. Duvall ◽  
Åke Flock ◽  
Jan Wersäll

From the apical end of the inner hair cell of the organ of Corti in the guinea pig cochlea protrude four to five rows of stereocilia shaped in a pattern not unlike the wings of a bird. In the area devoid of cuticular substance facing toward the tunnel of Corti lies a consistently present centriole. The ultrastructure of this centriole is similar to that of the basal body of the kinocilium located in the periphery of the sensory hair bundles in the vestibular and lateral line organ sensory cells and to that of the centrioles of other cells. The physiological implications of the anatomical orientation of this centriole are discussed in terms of directional sensitivity.


1981 ◽  
Vol 36 (5-6) ◽  
pp. 493-496 ◽  
Author(s):  
Bernd Fritzsch

Abstract The arrangement of the lateral line afferents of salamanders as revealed by transganglionic staining with horse­ radish peroxidase is described. Each lateral line organ is supplied by two fibers only. In the medulla these two afferent fibers run in separate fiber bundles. It is suggested, that only those fibers contacting lateral line sensory cells with the same polarity form together one bundle. Bundles formed by anterior or posterior lateral line afferents are also clearly separated. Beside the lateral line organs smaller pit organs are described. These organs are supplied by one afferent only which reveals an arrangement in the medulla different from that of the lateral line afferents. Based on anatomical facts, these small pit organs are considered to be electroreceptors. Centrifugally projecting neurons, most probably efferents, are described in the medulla.


1979 ◽  
Vol 55 (7) ◽  
pp. 374-379 ◽  
Author(s):  
Kouichi SHIOZAWA ◽  
Keiji YANAGISAWA

Bioacoustics ◽  
2002 ◽  
Vol 12 (2-3) ◽  
pp. 153-156 ◽  
Author(s):  
SIETSE M. VAN NETTEN ◽  
J. ESTHER C. WIERSINGA-POST

1988 ◽  
Vol 105 (sup447) ◽  
pp. 9-13
Author(s):  
Takashi Kanda ◽  
Toshio Yoshihara ◽  
Toshio Kaneko ◽  
Yuji Yaku ◽  
Osamu Hojiro ◽  
...  

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