A cytological study of Mauthner's cells in Xenopus laevis and Rana temporaria during metamorphosis

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 415-431
Author(s):  
J. M. Moulton ◽  
A. Jurand ◽  
H. Fox
Keyword(s):  
Xenopus Laevis ◽  
Rana Temporaria ◽  
Cytological Study ◽  
Nervous Activity ◽  
Special Kind ◽  
Functional System ◽  
Ventral Horn ◽  
M Cells ◽  
Anuran Larvae ◽  
Cytological Changes

This paper discusses cytological changes which occur during anuran metamorphosis in a pair of large hind-brain neurones, the Mauthner cells or M-cells which, in many teleosts and amphibians, innervate the tail musculature via ventral horn cells. The M-cells of fishes, urodeles and anuran larvae are unusually large neurones of particular interest, and according to Stefanelli (1951) they constitute a ‘true functional system of nervous activity’. The value of a cytological study is enhanced by the fact that amphibian M-cells have not yet been extensively analysed biochemically (Deuchar, 1966). In teleosts, the abundant synapses, apparently of a special kind, that terminate on M-cells have been studied by Bodian (1937), Furshpan & Furukawa (1962), Furukawa & Furshpan (1963), Furshpan (1964), Furukawa (1966), Robertson (1963), and Robertson, Bodenheimer & Stage (1963) and have been discussed by Eccles (1964).

The Kinematics of Swimming in Larvae of the Clawed Frog, Xenopus Laevis

1986 ◽  
Vol 122 (1) ◽  
pp. 1-12 ◽  
Author(s):  
KARIN VON SECKENDORFF HOFF ◽  
RICHARD JOEL WASSERSUG
Keyword(s):  
Xenopus Laevis ◽  
Swimming Speed ◽  
High Speed ◽  
Total Mass ◽  
Beat Frequency ◽  
Maximum Amplitude ◽  
Open Water ◽  
Computer Assisted ◽  
Anuran Larvae ◽  
Tail Beat

The kinematics of swimming in larval Xenopus laevis has been studied using computer-assisted analysis of high-speed (200 frames s−1) ciné records. The major findings are as follows. 1. At speeds below 6 body lengths (L) per second, tail beat frequency is approximately 10 Hz and, unlike for most aquatic vertebrates, is not correlated with specific swimming speed. At higher speeds, tail beat frequency and speed are positively correlated. 2. Xenopus tadpoles show an increase in the maximum amplitude of the tail beat with increasing velocity up to approximately 6Ls−1. Above that speed amplitude approaches an asymptote at 20 % of body length. 3. Anterior yaw is absent at velocities below 6Ls−1, unlike for other anuran larvae, but is present at higher speeds. 4. At speeds below 6Ls−1 there is a positive linear relationship between length of the propulsive wave (λ) and specific swimming speed. At higher speeds wavelength is constant at approximately 0.8L. 5. There is a shift in the modulation of wavelength and tail beat frequency with swimming speed around 5.6Ls−1, suggesting two different swimming modes. The slower mode is used during open water cruising and suspension feeding. The faster, sprinting mode may be used to avoid predators. 6. Froude efficiencies are similar to those reported for fishes and other anuran larvae. 7. Unlike Rana and Bufo larvae, the axial muscle mass of Xenopus increases dramatically with size from less than 10% of total mass for the smallest animals to more than 45% of total mass for the largest animals. This increase is consistent with maintaining high locomotor performance throughout development.

Endocrine effects of environmental pollution on Xenopus laevis and Rana temporaria

2003 ◽  
Vol 93 (2) ◽  
pp. 195-201 ◽  
Author(s):  
C. Bögi ◽  
J. Schwaiger ◽  
H. Ferling ◽  
U. Mallow ◽  
C. Steineck ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Environmental Pollution ◽  
Rana Temporaria ◽  
Endocrine Effects

scholarly journals Transfer of Primordial Germ-cells between Two Subspecies of Xenopus laevis

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 641-651
Author(s):  
A. W. Blackler
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Nuclear Membrane ◽  
Rana Temporaria ◽  
Primordial Germ Cells ◽  
Staining Technique ◽  
Tail Bud ◽  
Ventral Region ◽  
Large Size ◽  
The Poor

In Anura the primordial germ-cells are discernible in the dorsal crest endoderm of tail-bud stages of development and may be traced from this position throughout their migration into the undifferentiated gonadal rudiment. These facts have been established by the descriptive studies of a number of workers (see review by Johnston, 1951), the cells being recognizable by their large size, the retention of yolk platelets long after their disappearance in neighbouring cells, the sharply denned and often kidney-shaped nuclear membrane, and the poor staining affinity of the nuclear contents. By means of the application of the Altmann-Volkonsky staining technique, Bounoure (1934) was able to demonstrate that germ-cells of the dorsal crest endoderm are the lineal descendants of certain cells found in the ventral region of the blastula. This discovery has been confirmed for Rana temporaria (the species investigated by Bounoure) by Blackler (1958), and extended to other Anuran species by Nieuwkoop (1956 a, b), Blackler (1958), and Di Berardino (1961).

The response of the brachial ventral horn of Xenopus laevis to forelimb amputation during development

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 453-468
Author(s):  
Joanne E. Fortune ◽  
Antonie W. Blackler
Keyword(s):  
Xenopus Laevis ◽  
Normal Development ◽  
Developmental Stages ◽  
Neuronal Degeneration ◽  
Neuronal Loss ◽  
Cell Loss ◽  
Cell Number ◽  
Ventral Horn ◽  
Cell Degeneration ◽  
Cell Numbers

The normal development of the brachial ventral horn of the frog Xenopus laevis and the response of the brachial ventral horn to complete forelimb extirpation at five developmental stages were assessed histologically. Differentiation of brachial ventral horn neurons occurred in pre-metamorphic tadpoles between stages 52/53 and 57. Mean cell number in the brachial ventral horn reached a peak of 2576 (S.E.M. = ±269, n = 2) per side of the spinal cord at stage 55 and decreased to 1070 (S.E.M. = ± 35, n =7) by the end of metamorphosis. Cell degeneration was presumed to be the mode of cell loss since it was most prevalent during the period of rapid decrease in cell numbers. The response of the ventral horn to forelimb removal varied with the stage of the animal at amputation. Following amputation at stage 52/53 or 54 the ipsilateral ventral horn neurons appeared less differentiated than those on the controlside and a rapid cell loss of about 80 % occurred on the operated side. These effects occurred more rapidly after ablation at stage 54 than at stage 52/53. Amputation at stage 58, 61, or 66 caused chromatolysis in the ventral horn, a period of relative cell excess on the operated side, and a delayed neuronal loss of 32–66%. It was concluded that excess cell degeneration accounted for cell loss and that suppression of normal neuronal degeneration caused the relative cell excess on the operated side. The data indicate that the brachial ventral horn was indifferent to the periphery before stage 54, was quickly affected by limb removal between stages 54 and 58, and by stage 58 had entered a phase in which a delay preceded cell death. No forelimb regeneration occurred.

Les effets de la centrifugation sur la blastula et la jeune gastrula des Amphibiens

Development ◽  
1954 ◽  
Vol 2 (2) ◽  
pp. 122-148
Author(s):  
par J. Pasteels
Keyword(s):  
Xenopus Laevis ◽  
Nous Avons ◽  
Rana Temporaria ◽  
P 16

Nous avons montré dans les deux premiers mémoires de cette série que la centrifugation aux stades blastula et jeune gastrula peut provoquer une activation de l'ectoblaste; c'est à dire que sans aucune intervention d'un inducteur éventuel, l'ectoblaste constitue des tissus nerveux et neuroïdes, de la chorde, des somites, du pronéphros. Le caractère autonome de cette activité a pu être démontré par des expériences d'explantations (Pasteels, 1953a, p. 15) ou de greffes, soit homoplastiques (Pasteels, 1953a, p. 16), soit hétéroplastiques (Pasteels, 1953a, p. 17). La sensibilité de l'ectoblaste vis-à-vis de la centrifugation varie cependant suivant les espèces, et pour la meme espèce, suivant l'âge du développement (Pasteels, 1953b). C'est ainsi que chez des especes peu sensibles comme l'Axolotl ou Amblystoma punctatum, ou encore à des stades peu sensibles chez Rana temporaria ou Xenopus laevis, l'activation de l'ectoblaste ne depasse pas un stade subliminal.

The control of cell number in the lumbar ventral horns during the development of Xenopus laevis tadpoles

Development ◽  
1967 ◽  
Vol 18 (3) ◽  
pp. 359-387
Author(s):  
M. C. Prestige
Keyword(s):  
Xenopus Laevis ◽  
Cell Number ◽  
Ventral Horn ◽  
Early Evidence ◽  
Motor Neurones

The developing limb has been amputated by many workers in several species and in each case the number of surviving motor neurones on the side of the operation was less than normal. This may be observed among the mammals (e.g. Barron, 1945), birds (e.g. Hamburger, 1934), urodeles (e.g. Stultz, 1942), and anurans (e.g. May, 1930). The loss of motor neurones after amputation in adults appears to have been first noticed by Vulpian (1868) and Johnson & Clarke (1868). The early evidence is reviewed by Sherrington (1893) and the later by Piatt (1948). The control that the developing leg has over proliferation, migration, maintenance and degeneration of ventral horn cells has been most completely analysed in the chick, notably by Hamburger (1934, 1939, 1958), Hamburger & Keefe (1944), Bueker (1943, 1944, 1945a), Barron (1946, 1948), Mottet (1952) and Mottet & Barron (1954). Less is known about this in Anura.

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