scholarly journals Morphology of the utricular otolith organ in the toadfish, Opsanus tau

2018 ◽  
Vol 526 (9) ◽  
pp. 1571-1588 ◽  
Author(s):  
Richard Boyle ◽  
Reza Ehsanian ◽  
Alireza Mofrad ◽  
Yekaterina Popova ◽  
Joseph Varelas
Keyword(s):  
2001 ◽  
Vol 86 (4) ◽  
pp. 2118-2122 ◽  
Author(s):  
Richard Boyle ◽  
Allen F. Mensinger ◽  
Kaoru Yoshida ◽  
Shiro Usui ◽  
Anthony Intravaia ◽  
...  

The consequence of exposure to microgravity on the otolith organs was studied by recording the responses of vestibular nerve afferents supplying the utricular otolith organ to inertial accelerations in four toadfish, Opsanus tau, sequentially for 5 days following two National Aeronautics and Space Administration shuttle orbital flights. Within the first day postflight, the magnitude of response to an applied translation was on average three times greater than for controls. The reduced gravitational acceleration in orbit apparently resulted in an upregulation of the sensitivity of utricular afferents. By 30 h postflight, responses were statistically similar to control. The time course of return to normal afferent sensitivity parallels the reported decrease in vestibular disorientation in astronauts following return from space.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Adriana Salatino ◽  
Claudio Iacono ◽  
Roberto Gammeri ◽  
Stefano T. Chiadò ◽  
Julien Lambert ◽  
...  

AbstractOrienting attention in the space around us is a fundamental prerequisite for willed actions. On Earth, at 1 g, orienting attention requires the integration of vestibular signals and vision, although the specific vestibular contribution to voluntary and automatic components of visuospatial attention remains largely unknown. Here, we show that unweighting of the otolith organ in zero gravity during parabolic flight, selectively enhances stimulus-driven capture of automatic visuospatial attention, while weakening voluntary maintenance of covert attention. These findings, besides advancing our comprehension of the basic influence of the vestibular function on voluntary and automatic components of visuospatial attention, may have operational implications for the identification of effective countermeasures to be applied in forthcoming human deep space exploration and habitation, and on Earth, for patients’ rehabilitation.


1972 ◽  
Vol 65 (5) ◽  
pp. 515-522 ◽  
Author(s):  
Jun Kusakari ◽  
Yutaka Kaneko ◽  
Ichiro Kakizaki

1995 ◽  
Vol 198 (3) ◽  
pp. 755-766 ◽  
Author(s):  
P Walsh

The subcellular localization and biochemical properties of the enzymes of carbamoyl phosphate and urea synthesis were examined in three representatives of fishes of the family Batrachoididae, the gulf toadfish (Opsanus beta), the oyster toadfish (Opsanus tau) and the plainfin midshipman (Porichthys notatus). The primary objective of the study was to compare the biochemical characteristics of these fishes, which represent a range between ammoniotelism and ureotelism (O. beta being facultatively ureotelic), with previous patterns observed for an ammoniotelic teleost (Micropterus salmoides, the largemouth bass) and an obligate ureogenic elasmobranch (Squalus acanthias, the dogfish shark). The present study documents the expression of mitochondrial carbamoyl phosphate synthetase (CPSase) III and cytosolic CPSase II (and its associated enzymes of pyrimidine synthesis, dihydro-orotase and aspartate carbamoyltransferase) in the livers of all three batrachoidid species. Both mitochondrial and cytosolic activities of arginase were present in the livers of all three species, as were cytosolic glutamine synthetase and argininosuccinate synthetase and lyase. However, O. beta also showed mitochondrial glutamine synthetase activity and higher total hepatic levels of glutamine synthetase than either O. tau or P. notatus. Taken together, these observations confirm that the arrangement of these enzymes in the batrachoidid fishes has greater similarity to that of M. salmoides than to that of S. acanthias. However, differences within the family appear to coincide with the different nitrogen excretion strategies. O. tau and P. notatus are primarily ammoniotelic and most closely resemble the ammoniotelic M. salmoides, whereas ureotelism in O. beta is correlated with the presence of a mitochondrial glutamine synthetase and the ability to induce higher total glutamine synthetase activities than O. tau or P. notatus. Additionally, isolated mitochondria from O. beta were able to generate citrulline from glutamine, whereas those from O. tau were not. Also in contrast to S. acanthias, glutamine synthetase activities in the mitochondria of O. beta are consistently lower than those of CPSase III. This and other kinetic observations lend support to the hypothesis that glutamine synthetase may be an important regulatory control point in determining rates of ureogenesis in O. beta.


1997 ◽  
Vol 193 (2) ◽  
pp. 272-272 ◽  
Author(s):  
L. Shapiro ◽  
R. A. Bullis ◽  
R. M. Smolowitz ◽  
S. Slavinsky

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