Neurotransmitter synthesis in inner ear and lateral line sense organs

  title={Neurotransmitter synthesis in inner ear and lateral line sense organs},
  author={Ake Flock and DOMINIC M. K. LAM},
  • A. FlockDOMINIC M. K. LAM
  • Published 10 May 1974
  • Biology
  • Nature
HAIR cells of inner ear sense organs and of lateral line organs in fish are innervated by afferent nerve fibres, to which they transmit information about mechanical stimuli. Efferent inhibitory nerve fibres, which originate in the central nervous system, also innervate most hair cells at their base (Fig. 1b). Recent evidence indicates that both these synapses are chemical; excitatory postsynaptic potentials (e.p.s.p.s) have been recorded in afferent nerve terminals in response to mechanical… 

Information Transfer at the Synapse between Hair Cells and Sensory Nerve Fibres

The most common type of hair cell is dealt with, that which has afferent and efferent nerve endings side by side innervating the hair cell base, designed commonly as Type II hair cells (Wersall, 1956).

The Efferent Vestibular System

The chapter describes the vestibular and nonvestibular signals carried by efferent neurons and how these signals might modify the information carried by afferents, and results in nonmammalian species are considered, as these provide insights into efferent function.

Neurotransmission in the inner ear

Synaptic vesicles in the cochlea.

The character of intra-cochlear synaptic vesicles was investigated in order to throw some light on transmitter identity and a catecholamine appeared to be the transmitter in the sympathetic nerve.

Ultrastructure of synapses in the lateral line canal organ.

The ultrastructure of afferent and efferent synapses on hair cells in the lateral line canal organ of hair cells of the fish Lota lota was studied, utilizing various fixation and staining techniques.

Pharmacology of the vestibular hair cell-afferent fiber synapse in the frog

The isolated, intact, membranous labyrinth of the frog has been investigated electrophysiologically in vitro to determine the nature of the transmitter substance at the synapse between the vestibular hair cells and afferent fibers, suggesting that glutamate, aspartate, or a related compound is the transmitter.

Electrical and mechanical stimulation of hair cells in the mudpuppy

The conclusion is therefore that the mechanically evoked receptor potentials in hair cells have a direct effect on the transmitter release, and the potentials are not an epiphenomenon caused by the secretory activity of the hair cells.

Neuroactive substances in inner ear extracts

  • W. F. SewellE. Mroz
  • Biology
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1987
The high-molecular-weight excitatory substance is present both in brain and in inner ear, and some extracts also contain a high- molecular-weight inhibitory substance, which is detected in extracts of innerEar, but not in brain or muscle.

Neurobiology of Hair Cells and Their Synapses

There is reason to believe that hair cells in the cochlea, in the vestibular system and in lateral line organs work according to the same basic principles, with the possible exception of synaptic transmission in mammalian Vestibular Type I hair cells.



The role of the lateral-line efferent system in Xenopus laevis.

  • I. Russell
  • Biology
    The Journal of experimental biology
  • 1971
In immobilized animals a close correlation exists between impulses in lateral-line efferent nerve fibres and motor impulses in ‘large’ nerves innervating ‘twitch’ muscles, but not with impulses in nerves innervation ‘slow’ muscle, and a role of the lateral- line efferent neurones during active movement is discussed.

The pharmacology of efferent synapses in the lateral-line system of Xenopus laevis.

  • I. Russell
  • Biology
    The Journal of experimental biology
  • 1971
Arguments are put forward to support the hypothesis that acetylcholine is released at lateral-line efferent synapses in a way similar to that found at the amphibian neuromuscular junction.

Effects of Divalent Ions and Drugs on Synaptic Transmission in Phasic Electroreceptors in a Mormyrid Fish

L-glutamate, and not cholinergic drugs, produces a sequence of excitation and depression of medium receptor response which indicates that a similar chemical is the transmitter in the afferent synapse, which supports previous suggestions that transmission is chemically mediated in medium receptors and electrically mediated in large receptors.

Cholinesterase and its relation to the nerve endings in the inner ear.

The inner ear sensory epithelia in the guinea pig were stained with Holmstedt's modification of Koelle's thiocholine method for localization of cholinesterase activity and the staining reaction was

Ultrastructure of the basilar papilla, an auditory organ in the bullfrog.

Examination of the papilla in the bullfrog, Rana catesbeiana, by light and electron microscopy has confirmed earlier descriptions of its gross morphology and revealed new details of its fine structure.


Abstract— Choline acetyltransferase (ChAc; EC was assayed in the membranous cochlea and in the eighth cranial nerve (both the vestibular and cochlear components) from the point where it

Anatomical distribution of efferent fibers in the 8th cranial nerve of the bullfrog (Rana catesbeiana).

The VIIIth cranial nerve of the bullfrog was surgically transected between the brain stem and sensory ganglion to demonstrate the presence of efferent fibers going toward the sensory epithelium of all the recognized vestibular end-organs, and also toward the papilla of the pars amphibiorum.


  • K. Hama
  • Biology
    The Journal of cell biology
  • 1965
The fine structure of the lateral line organ of the Japanese sea eel Lyncozymba nystromi has been studied with the electron microscope and the morphological relationship between the supporting cells and the receptor cells were observed.


  • D. M. Lam
  • Biology
    The Journal of cell biology
  • 1972
It is suggested that GABA plays a functional role in synaptic transmission in the goldfish retina through its role in synthesizing γ-aminobutyric acid-14C (GABA- 14C), which was enhanced by physiological stimulation of the retina with flashing light.

Screening for neurotransmitters: a rapid radiochemical procedure.

A rapid screening procedure for identifying which of these substances are likely candidates for neurotransmitters in a particular tissue, based on the selective synthesis and localization of transmitters in those cells which are presumed to release them.