On the role of the central nervous system in regulating the mineralisation of inner-ear otoliths of fish.

Stato- or otoliths are calcified structures in the organ of balance and equilibrium of vertebrates, the inner ear, where they enhance its sensitivity to gravity. The compact otoliths of fish are composed of the calcium carbonate polymorph aragonite and a small fraction of organic molecules. The latter form a protein skeleton which determines the morphology of an otolith as well as its crystal lattice structure.

Hypergravity decreases carbonic anhydrase-reactivity in inner ear maculae of fish.

Previous investigations revealed that fish inner ear otolith growth depends on the amplitude and the direction of gravity. Both otolith total size, otolith bilateral size-asymmetry and the total and bilateral calcium-incorporation are also affected by gravity. Hypergravity, e.

Histology of the utricle in kinetotically swimming fish: a parabolic aircraft flight study.

Objectives: Humans taking part in parabolic aircraft flights (PAFs) may suffer from space motion sickness, which is a form of kinetosis. As it has been repeatedly shown that some fish in a given batch also reveal kinetotic behaviour (especially so-called spinning movements and looping responses) during PAFs, and as a result of the homology of the vestibular apparatus of all vertebrates, fish can be used as model systems to investigate the origin of susceptibility to motion sickness. Therefore.

Neurophysiology of developing fish at altered gravity: background--facts--perspectives.

During the entire evolution of life on Earth, the phylogenetic as well as the individual development of all organisms took place under constant gravity conditions, against which they achieved specific countermeasures for compensation and adaptation. On the one side, gravity represents a factor of physical restriction, which compelled the ancestors of all extant living beings to develop basic achievements to counter the gravitational force (e.g.

On the origin of susceptibility to kinetotic swimming behaviour in fish: a parabolic aircraft flight study.

Humans taking part in parabolic aircraft flights (PAFs) may suffer from motion sickness (SMS, a kinetosis; it comprises a dynamic and a static component). It has been argued that the so-called static variety of SMS during PAFs might be based on asymmetric statoliths (i.e.

Susceptibility to abnormal (kinetotic) swimming fish correlates with inner ear carbonic anhydrase-reactivity.

Larval cichlid fish (Oreochromis mossambicus) were kept at hypergravity (hg; centrifuge) for 6 h. Following the transfer to 1 g (i.e.