Synaptic potentials in afferent fibers innervating hair cells of the lateral line organ in Xenopus laevis

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.

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Contribution of glutamate receptors to spontaneous and stimulus-evoked discharge in afferent fibers innervating hair cells of the Xenopus lateral line organ

Hearing Research ◽

10.1016/s0378-5955(00)00023-x ◽

2000 ◽

Vol 144 (1-2) ◽

pp. 8-20 ◽

Cited By ~ 5

Author(s):

Gerald P Bailey ◽

William F Sewell

Keyword(s):

Glutamate Receptors ◽

Lateral Line ◽

Hair Cells ◽

Lateral Line Organ ◽

Afferent Fibers ◽

Line Organ

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Electroreceptors and Direction Specific Arrangement in the Lateral Line System of Salamanders?

Zeitschrift für Naturforschung C ◽

10.1515/znc-1981-5-628 ◽

1981 ◽

Vol 36 (5-6) ◽

pp. 493-496 ◽

Cited By ~ 20

Author(s):

Bernd Fritzsch

Keyword(s):

Lateral Line ◽

Fiber Bundles ◽

Sensory Cells ◽

Lateral Line System ◽

Line System ◽

Lateral Line Organ ◽

Posterior Lateral Line ◽

Afferent Fibers ◽

Lateral Line Afferents ◽

Line Organ

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.

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