Variations of glycogen: II. Following deafferentation of Knollenorgan sensory cells, a lateral line electroreceptor of mormyrid fish

1995 ◽  
Vol 165 (5) ◽  
pp. 336-340
Author(s):  
B. A. Djebar ◽  
J. -P. Denizot
Keyword(s):  
Lateral Line ◽  
Sensory Cells ◽  
Mormyrid Fish

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

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

1981 ◽  
Vol 36 (5-6) ◽  
pp. 493-496 ◽  
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.

The fine structure of ampullary electric receptors in Amiurus

1964 ◽  
Vol 160 (980) ◽  
pp. 345-359 ◽  
Keyword(s):  
Fine Structure ◽  
Lateral Line ◽  
Cell Group ◽  
Sensory Cells ◽  
Receptor Cells ◽  
Pit Organ ◽  
Accessory Cells ◽  
Myelinated Nerves ◽  
Square Array ◽  
Small Nerve

The small pit-organs of Amiurus have been included in the group of ampullary lateral-line organs. On morphological and physiological grounds these ampullary organs are thought to be electric receptors and not mechano-receptors; thus they can be distinguished from all other types of acoustico-lateralis organs of vertebrates. Each small pit-organ consists of a duct leading from the surface of the skin to an ampulla, beneath which there is a group of cells lying at the base of the epidermis. There are two main types of cells in this group: the receptor and the accessory cells. The apical surfaces of the receptor cells bear microvillae but no cilia: these microvillae project into the lumen of the ampulla. Myelinated nerves supply the organs at the base ; they lose their myelin sheaths before entering the cell group where they branch and innervate the receptor cells. Small nerve terminals are closely applied to the surface of the receptor cells and in some places are thought to be in synaptic contact. Near these regions characteristic dense bodies are found in the base of the receptor cells. The bodies are surrounded by an accumulation of small vesicles of about 300 to 500 Å in diameter; they resemble structures found in corresponding situations in other types of sensory cells. Dense inclusions are found in some receptor cells: these inclusions have a highly ordered fine structure which in some sections appears as a square array of dense dots having a centre-to-centre spacing of about 75 Å. These observations are discussed in relation to the supposed activity of small pit-organs as electric receptors and to their position in the group of ampullary lateral-line organs.

Sensory Cells and Pigment Distribution in the Tail of the Ammocoete

1951 ◽  
Vol s3-92 (19) ◽  
pp. 233-247
Author(s):  
D. M. STEVEN
Keyword(s):  
Lateral Line ◽  
Free State ◽  
Sensory Cells ◽  
Light Reaction ◽  
Lampetra Planeri ◽  
Colour Changes ◽  
Pigment Distribution

The ammocoete of Lampetra planeri (Bloch) contains a single carotenoid, lutein, partly esterified and partly in the free state. The pigment is distributed in lipophores in the sub-dermal tissues, and plays no part in the colour changes of-the animal. The epidermis of the tail contains numerous sensory cells of a type previously undescribed, which satisfy the requirements predicted for the photoreceptors responsible for the light reaction of the animal. Evidence is presented that these sensory cells are innervated by branches of the lateral line nerves. Similarities are indicated between the sensory cells of the ammocoete and simple photoreceptor systems of certain invertebrates.

Mormyromast electroreceptor organs and their afferent fibers in mormyrid fish. III. Physiological differences between two morphological types of fibers

1990 ◽  
Vol 63 (2) ◽  
pp. 319-332 ◽  
Author(s):  
C. C. Bell
Keyword(s):  
Tuning Curve ◽  
Conditioning Stimulus ◽  
Receptor Potential ◽  
Sensory Cells ◽  
High Threshold ◽  
Afferent Fibers ◽  
Mormyrid Fish ◽  
Spike Number ◽  
Low Threshold ◽  
Physiological Differences

1. Mormyromast electroreceptor organs in electric fish of the family Mormyridae have two types of separately innervated sensory cells, the A and B sensory cells of Szabo and Wersall. The first paper in this series showed anatomically that afferent fibers from the two types of sensory cell terminate centrally in separate zones of the electrosensory lateral line lobe (ELL), fibers from A cells terminating in the medial zone and fibers from B cells terminating in the dorsolateral zone. The goal of the present study was to determine the physiological differences between the two morphologically distinct types of mormyromast afferent fibers. 2. The present study has two parts. In the first part, mormyromast fibers were recorded near their central terminals in the two mormyromast zones of ELL. In the second part, mormyromast fibers were recorded from a peripheral electrosensory nerve. In both parts, various electrosensory stimuli were delivered and voltage thresholds were measured at the electroreceptor. 3. In the first part of the study, mormyromast fibers terminating in the two central zones were found to be different in their thresholds and in the maximum number of spikes evoked by a single stimulus. Afferent fibers terminating in the medial zone, which arise from A sensory cells, had higher thresholds and smaller maximum spike numbers than fibers terminating in the dorsolateral zone, which arise from B sensory cells. 4. In the second part of the study, the same two groups of fibers--one group with a high threshold and a small maximum spike number, and a second group with a low threshold and a large maximum spike number--were identified in extracellular recordings from a peripheral electrosensory nerve. The thresholds of the two groups were quite distinct, allowing the fibers to be divided into high- and low-threshold groups, which most likely represent the fibers from the A and B sensory cells, respectively. 5. The high- and low-threshold groups of fibers recorded from peripheral nerve were found to be different in a number of additional properties besides threshold and maximum spike number. Additional differences were found in the following properties: strength-duration curve, correlation with a receptor potential recorded at the electroreceptor, tuning curve, and short latency facilitation by a conditioning stimulus. Thus there appear to be several physiological differences between mormyromast afferent fibers from A and B sensory cells, in addition to the differences in threshold and spike number.(ABSTRACT TRUNCATED AT 400 WORDS)

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