scholarly journals RAPID DEGENERATION OF AMPULLARY ELECTRORECEPTOR ORGANS AFTER DENERVATION

1973 ◽  
Vol 56 (2) ◽  
pp. 466-477 ◽  
Author(s):  
R. Bruce Szamier ◽  
Michael V. L. Bennett
Keyword(s):  
Nerve Fiber ◽  
Lateral Line ◽  
Receptor Cell ◽  
Secretory Cells ◽  
Supporting Cells ◽  
Nerve Section ◽  
Structural Alterations ◽  
Lateral Line Nerve ◽  
Receptor Cells ◽  
Afferent Innervation

Electroreceptors (ampullary organs) of the transparent catfish (Kryptopterus bicirrhus) lie in the epidermis, and contain spherical receptor cells that receive purely afferent innervation from the lateral line nerve. Section of this nerve causes rapid degenerative changes to occur in the receptors. Fine structural alterations occur in the receptor cell synapses and nerve fiber 6–12 h postoperatively. Disruption of the receptor cells begins by 18 h and most are lost by 48 h. By 72 h supporting cells and secretory cells also show marked degeneration, and by 96 h they may be totally lost. The rapid degeneration of the electroreceptor organs of Kryptopterus should make them a useful preparation for analysis of neurotrophic functions.

scholarly journals SOME OBSERVATIONS ON THE FINE STRUCTURE OF THE LATERAL LINE ORGAN OF THE JAPANESE SEA EEL LYNCOZYMBA NYSTROMI

1965 ◽  
Vol 24 (2) ◽  
pp. 193-210 ◽  
Author(s):  
Kiyoshi Hama
Keyword(s):  
Fine Structure ◽  
Lateral Line ◽  
Receptor Cell ◽  
Sensory Epithelium ◽  
Nerve Fibers ◽  
Supporting Cells ◽  
Lateral Line Nerve ◽  
Lateral Line Organ ◽  
The Individual ◽  
Line Organ

The fine structure of the lateral line organ of the Japanese sea eel Lyncozymba nystromi has been studied with the electron microscope. The sensory epithelium of the lateral line organ consists of a cluster of two major types of cells, the sensory hair cells and the supporting cells. The sensory cell is a slender element with a flat upper surface provided with sensory hairs, Two different types of synapses are distinguished on the basal surface of the receptor cell. The first type is an ending without vesicles and the second type is an ending with many vesicles. These are presumed to correspond to the afferent and the efferent innervations of the lateral line organ. The fine structure of the supporting cells and the morphological relationship between the supporting cells and the receptor cells were observed. The possible functions of the supporting cells are as follows: (a) mechanical and metabolic support for the receptor cell; (b) isolation of the individual receptor cell; (c) mucous secretion and probably cupula formation; (d) glial function for the intraepithelial nerve fibers. Both myelinated and unmyelinated fibers were found in the lateral line nerve. The mode of penetration of these fibers into the epithelium was observed.

scholarly journals ACTION CURRENT OF THE SINGLE LATERAL-LINE NERVE FIBER OF FISH

1950 ◽  
Vol 1 ◽  
pp. 179-194 ◽  
Author(s):  
YASUJI KATSUKI ◽  
SHIZUO YOSHINO ◽  
JUNG CHEN
Keyword(s):  
Nerve Fiber ◽  
Lateral Line ◽  
Action Current ◽  
Lateral Line Nerve

scholarly journals THE CARBON DIOXIDE EXCRETED IN ONE MINUTE BY ONE CENTIMETER OF NERVE-FIBER

1925 ◽  
Vol 9 (2) ◽  
pp. 191-195 ◽  
Author(s):  
G. H. Parker
Keyword(s):  
Carbon Dioxide ◽  
Nerve Fiber ◽  
Lateral Line ◽  
Lateral Line Nerve

One centimeter of nerve-fiber from the lateral-line nerve of the dogfish is estimated to excrete on the average 4.2 x 10–8 mg. CO2 per minute.

Regeneration of the lateral line nerve of Amblystoma from different nerve fiber sources

1943 ◽  
Vol 87 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Paul Weiss ◽  
Jean B. Cummings
Keyword(s):  
Nerve Fiber ◽  
Lateral Line ◽  
Lateral Line Nerve

scholarly journals A STUDY OF THE ORIENTATION OF THE SENSORY HAIRS OF THE RECEPTOR CELLS IN THE LATERAL LINE ORGAN OF FISH, WITH SPECIAL REFERENCE TO THE FUNCTION OF THE RECEPTORS

1962 ◽  
Vol 15 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Åke Flock ◽  
Jan Wersäll
Keyword(s):  
Lateral Line ◽  
Teleost Fish ◽  
Receptor Cell ◽  
The Other ◽  
Receptor Cells ◽  
Lateral Line Organ ◽  
Sensory Hairs ◽  
Crista Ampullaris ◽  
Functional Polarization ◽  
Line Organ

The morphology of the hair bundles on top of the receptor cells in the lateral line organ of the teleost fish Lota vulgaris is described. Each receptor cell shows a distinct morphological polarization. Two groups of receptor cells can be distingiushed, one consisting of cells polarized towards the head, the other consisting of cells polarized towards the tail. In the crista ampullaris all cells are polarized in the same direction. An hypothesis is proposed for the function of the receptor cells in the lateral line organ and the labyrinth based on a correlation of morphological and functional polarization.

scholarly journals ACTION CURRENTS OF THE SINGLE LATERAL-LINE NERVE FIBER OF FISH

1950 ◽  
Vol 1 ◽  
pp. 87-99 ◽  
Author(s):  
YASUJI KATSUKI ◽  
SHIZUO YOSHINO ◽  
JUNG CHEN
Keyword(s):  
Nerve Fiber ◽  
Lateral Line ◽  
Lateral Line Nerve

scholarly journals SYNAPTIC INHIBITION IN AN ISOLATED NERVE CELL

1955 ◽  
Vol 39 (1) ◽  
pp. 155-184 ◽  
Author(s):  
Stephen W. Kuffler ◽  
Carlos Eyzaguirre
Keyword(s):  
Nerve Fiber ◽  
Cell Body ◽  
Inhibitory Action ◽  
Receptor Cell ◽  
Stretch Receptor ◽  
Synaptic Activity ◽  
Resting Potential ◽  
Generator Potential ◽  
Receptor Cells ◽  
Set Up

Following the preceding studies on the mechanisms of excitation in stretch receptor cells of crayfish, this investigation analyzes inhibitory activity in the synapses formed by two neurons. The cell body of the receptor neuron is located in the periphery and sends dendrites into a fine muscle strand. The dendrites receive innervation through an accessory nerve fiber which has now been established to be inhibitory. There exists a direct peripheral inhibitory control mechanism which can modulate the activity of the stretch receptor. The receptor cell which can be studied in isolation was stimulated by stretch deformation of its dendrites or by antidromic excitation and the effect of inhibitory impulses on its activity was analyzed. Recording was done mainly with intracellular leads inserted into the cell body. 1. Stimulation of the relatively slowly conducting inhibitory nerve fiber either decreases the afferent discharge rate or stops impulses altogether in stretched receptor cells. The inhibitory action is confined to the dendrites and acts on the generator mechanism which is set up by stretch deformation. By restricting depolarization of the dendrites above a certain level, inhibition prevents the generator potential from attaining the "firing level" of the cell. 2. The same inhibitory impulse may set up a postsynaptic polarization or a depolarization, depending on the resting potential level of the cell. The membrane potential at which the inhibitory synaptic potential reverses its polarity, the equilibrium level, may vary in different preparations. The inhibitory potentials increase as the resting potential is displaced in any direction from the inhibitory equilibrium. 3. The inhibitory potentials usually rise to a peak in about 2 msec. and decay in about 30 msec. After repetitive inhibitory stimulation a delayed secondary polarization phase has frequently been seen, prolonging the inhibitory action. Repetitive inhibitory excitation may also be followed by a period of facilitation. Some examples of "direct" excitation by the depolarizing action of inhibitory impulses are described. 4. The interaction between antidromic and inhibitory impulses was studied. The results support previous conclusions (a) that during stretch the dendrites provide a persisting "drive" for the more central portions of the receptor cell, and (b) that antidromic all-or-none impulses do not penetrate into the distal portions of stretch-depolarized dendrites. The "after-potentials" of antidromic impulses are modified by inhibition. 5. Evidence is presented that inhibitory synaptic activity increases the conductance of the dendrites. This effect may occur in the absence of inhibitory potential changes.

Ultrastructural aspects of olfactory signal transduction and its development

1994 ◽  
Vol 52 ◽  
pp. 142-143
Author(s):  
Bert Ph. M. Menco
Keyword(s):  
Signal Transduction ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Freeze Substitution ◽  
Luminal Surface ◽  
Tissue Sections ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Olfactory Signal ◽  
Odor Molecule

Vertebrate olfactory receptor cells are specialized neurons that have numerous long tapering cilia. The distal parts of these cilia line the interface between the external odorous environment and the luminal surface of the olfactory epithelium. The length and number of these cilia results in a large surface area that presumably increases the chance that an odor molecule will meet a receptor cell. Advanced methods of cryoprepration and immuno-gold labeling were particularly useful to preserve the delicate ultrastructural and immunocytochemical features of olfactory cilia required for localization of molecules involved in olfactory signal-transduction. We subjected olfactory tissues to freeze-substitution in acetone (unfixed tissues) or methanol (fixed tissues) followed by low temperature embedding in Lowicryl K11M for that purpose. Tissue sections were immunoreacted with several antibodies against proteins that are presumably important in olfactory signal-transduction.

Presynaptic Afferent Inhibition of Lobster Olfactory Receptor Cells: Reduced Action-Potential Propagation Into Axon Terminals

1998 ◽  
Vol 80 (2) ◽  
pp. 1011-1015 ◽  
Author(s):  
Matt Wachowiak ◽  
Lawrence B. Cohen
Keyword(s):  
Action Potential ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Action Potential Propagation ◽  
Cell Axon ◽  
Axon Terminals ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Afferent Inhibition ◽  
Reduced Action

Wachowiak, Matt and Lawrence B. Cohen. Presynaptic afferent inhibition of lobster olfactory receptor cells: reduced action-potential propagation into axon terminals. J. Neurophysiol. 80: 1011–1015, 1998. Action-potential propagation into the axon terminals of olfactory receptor cells was measured with the use of voltage-sensitive dye imaging in the isolated spiny lobster brain. Conditioning shocks to the olfactory nerve, known to cause long-lasting suppression of olfactory lobe neurons, allowed the selective imaging of activity in receptor cell axon terminals. In normal saline the optical signal from axon terminals evoked by a test stimulus was brief (40 ms) and small in amplitude. In the presence of low-Ca2+/high-Mg2+ saline designed to reduce synaptic transmission, the test response was unchanged in time course but increased significantly in amplitude (57 ± 16%, means ± SE). This increase suggests that propagation into receptor cell axon terminals is normally suppressed after a conditioning shock; this suppression is presumably synaptically mediated. Thus our results show that presynaptic inhibition occurs at the first synapse in the olfactory pathway and that the inhibition is mediated, at least in part, via suppression of action-potential propagation into the presynaptic terminal.

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