Horseradish Peroxidase Study of Tectal Afferents in Xenopus laevis with Special Emphasis on Their Relationship to the Lateral-Line System

1988 ◽  
Vol 32 (4) ◽  
pp. 208-219 ◽  
Author(s):  
K.E. Zittlau ◽  
B. Claas ◽  
H. Münz
Keyword(s):  
Horseradish Peroxidase ◽  
Xenopus Laevis ◽  
Lateral Line ◽  
Lateral Line System ◽  
Line System

Development of the lateral line system in Xenopus laevis

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 283-296
Author(s):  
Rudolf Winklbauer ◽  
Peter Hausen
Keyword(s):  
Xenopus Laevis ◽  
Lateral Line ◽  
Cell Number ◽  
Fixed Number ◽  
Cell Multiplication ◽  
Second Phase ◽  
Lateral Line System ◽  
Detailed Model ◽  
Line System ◽  
Organ Formation

Cell multiplication was studied during development of the supraorbital lateral line system in Xenopus laevis. The increase in cell number is biphasic. The first phase extends from the beginning of primordial elongation to the end of primary organ formation. Cell number increases linearly during this interval. Throughout this phase, a constant number of cells is in S phase of the cell cycle at a given time, despite a more than 10-fold increase in total cell number. After their formation, the number of the primary organs remains essentially constant. The individual primary organs are not clones of cells. Different organs grow at different rates, and become more and more heterogeneous in size. The second phase which is correlated with accessory organ formation is characterized by an elevated growth rate. This phase was not studied in detail. If developing larvae are starved, growth is normal up to completion of the first growth phase but is arrested at this point. The frequency distribution of the sizes of such growth-arrested organs approximates a binominal distribution. From its characteristics, a detailed model of cell proliferation and organ formation can be deduced: cell multiplication occurs through asymmetrically dividing stem cells, which become allocated to the forming organs at random and go through a fixed number of cell divisions.

scholarly journals The early development and physiology of Xenopus laevis tadpole lateral line system

2020 ◽  
Author(s):  
Valentina Saccomanno ◽  
Heather Love ◽  
Amy Sylvester ◽  
Wen-Chang Li
Keyword(s):  
Xenopus Laevis ◽  
Lateral Line ◽  
Motor Nerve ◽  
Sensory Information ◽  
Lateral Line System ◽  
Line System ◽  
Full Life Cycle ◽  
Summary Statement ◽  
Escape Responses ◽  
Mechanosensory System

AbstractXenopus laevis has a lateral line mechanosensory system throughout its full life cycle. Previous studies of the tadpole lateral line system revealed that it may play a role in escape behaviour. In this study, we used DASPEI staining to reveal the location of tadpole lateral line neuromasts. Destroying these neuromasts with neomycin resulted in loss of escape responses in tadpoles. We then studied the physiology of anterior lateral line in immobilised tadpoles. Activating the neuromasts behind one eye could evoke asymmetrical motor nerve discharges when the tadpole was resting, suggestive of turning/escape, followed by fictive swimming. When the tadpole was already producing fictive swimming however, anterior lateral line activation reliably led to the termination of swimming. The anterior lateral line had spontaneous afferent discharges at rest, and when activated showed typical adaptation. There were also efferent activities during tadpole swimming, the activity of which was loosely in phase with ipsilateral motor nerve discharges, implying modulation by the motor circuit from the same side. Calcium imaging experiments located sensory interneurons in the primary anterior lateral line nucleus in the hindbrain. Future studies are needed to reveal how sensory information is processed by the central circuit to determine tadpole motor behaviour.Summary statementActivating tadpole anterior lateral line evokes escape responses followed by swimming and halts ongoing swimming. The afferent and efferent activities and sensory interneuron locations in the hindbrain are reported.

The lateral line system at metamorphosis in Xenopus laevis (Daudin)

Development ◽  
1970 ◽  
Vol 24 (3) ◽  
pp. 511-524 ◽  
Author(s):  
Peter M. J. Shelton
Keyword(s):  
Xenopus Laevis ◽  
Lateral Line ◽  
Skin Surface ◽  
Directional Sensitivity ◽  
Lateral Line System ◽  
Line System

Marked changes in the anatomy of the lateral line system occur during the metamorphosis of Xenopus. The distribution of rows differs in larva and adult and the orientation and number of organs are modified at metamorphosis. Larval plaques are functional, as shown by recording from their nerves. Two classes of cells with polarized cilia are present in the tadpole well before the orientation of individual organ plaques is rearranged at metamorphosis. The topography of the skin surface around individual plaques changes at metamorphosis. This change may reduce the directional sensitivity of organs. Myelinated inhibitory axons in the lateralis nerve are found only when the tadpole matures. This change takes place at a time when the adult method of locomotion is developed.

Development of the lateral line system in Xenopus laevis

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 265-281
Author(s):  
Rudolf Winklbauer ◽  
Peter Hausen
Keyword(s):  
Xenopus Laevis ◽  
Lateral Line ◽  
Growth Zone ◽  
Cell Multiplication ◽  
Active Movement ◽  
Lateral Line System ◽  
Main Role ◽  
Dorsal Margin ◽  
Line System ◽  
Dividing Cells

During development of Xenopus laevis, the supraorbital lateral line system (i.e. the parietal and supraorbital lines of organs and the anterior auditory group of organs) is all derived from a single primordium located in the ear region of the epidermis. The primordium elongates first by active movement along the dorsal margin of the eye. Individual primary organs are then formed by progressive fragmentation of the streak-like primordium. After fragmentation, passive displacement of the organs due to skin growth seems to play the main role in altering the arrangement of the line system. Transplantation experiments confirmed that non-placodal epidermal cells are not incorporated into the developing system. The active elongation of the primordium is due to cell multiplication, and not due to cell rearrangement or change in cell shape or size. Cell multiplication is not confined to a growth zone, but dividing cells are randomly distributed throughout the primordium. All cells of a primordium have to change position during its elongation.

scholarly journals The early development and physiology of Xenopus laevis tadpole lateral line system

2021 ◽  
Author(s):  
Valentina Saccomanno ◽  
Heather M Love ◽  
Amy L Sylvester ◽  
Wen-Chang Li
Keyword(s):  
Xenopus Laevis ◽  
Lateral Line ◽  
High Speed ◽  
Motor Nerve ◽  
Sensory Information ◽  
Lateral Line System ◽  
Line System ◽  
Motor Responses ◽  
Lateral Line Nerve ◽  
Full Life Cycle

Xenopus laevis has a lateral line mechanosensory system throughout its full life cycle and a previous study on pre-feeding stage tadpoles revealed that it may play a role in motor responses to both water suction and water jets. Here, we investigated the physiology of the anterior lateral line system in newly hatched tadpoles and the motor outputs induced by its activation in response to brief suction stimuli. High-speed videoing showed tadpoles tended to turn and swim away when strong suction was applied close to the head. The lateral line neuromasts were revealed by using DASPEI staining, and their inactivation with neomycin eliminated tadpole motor responses to suction. In immobilised preparations, suction or electrically stimulating the anterior lateral line nerve reliably initiated swimming but the motor nerve discharges implicating turning was observed only occasionally. The same stimulation applied during ongoing fictive swimming produced a halting response. The anterior lateral line nerve showed spontaneous afferent discharges at rest and increased activity during stimulation. Efferent activities were only recorded during tadpole fictive swimming and were largely synchronous with the ipsilateral motor nerve discharges. Finally, calcium imaging identified neurons with fluorescence increase time-locked with suction stimulation in the hindbrain and midbrain. A cluster of neurons at the entry point of the anterior lateral line nerve in the dorsolateral hindbrain had the shortest latency in their responses, supporting their potential sensory interneuron identity. Future studies need to reveal how the lateral line sensory information is processed by the central circuit to determine tadpole motor behaviour.

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