title: [Contribution to the study of the effects of weightlessness on the central nervous system of the rat].
abstract: We have studied the effects of various states of acceleration on the physiological activity of white rats. Initial experimental trials were carried out in the course of a flight of the Veronique missile. In another series of experiments the trials took place in an airplane in the course of successive parabolic flights at several minutes intervals producing periods of weightlessness of 33 to 44 seconds. We recorded the electrical activity of a large area lying between one electrode located in the somesthesic area and another electrode located in the homolateral visual area. In addition, cardiac and respiratory rate and electrical activity of the mesencephalic reticular formation and of the muscles of the neck were recorded. We found an intense cortical activation during the entire duration of the missile flight. In the airplane during the periods of weightlessness basic electrical activity has not been modified. Recordings of electrical activity in the mesencephalic reticular formation do not show any modification during missile flight. Afterwards appeared a flattening with the reduction of frequency. In the course of periods of weightlessness in airplane flight we have observed no modification of background electrical activity. Recording of neck muscle potentials shows, during weightlessness in airplane flight, a distinct augmentation of background tone. These findings seem in favor of a facilitation of reticular origin as a result of the abrupt diminution of volume of sensory information following the disappearance of the stimulus of gravity.
authors.affiliation: Centre d'Enseignement et de Recherches de Medecine Aeronautique, Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Grandpierre
authors.forename: F
authors.initials: F
authors.lastname: Violette
mesh_terms: D000054:Acceleration; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D018471:Hypergravity; D018482:Muscle, Skeletal / Q000502:physiology; D009333:Neck; D051381:Rats; D012154:Reticular Formation / Q000502:physiology*; D013026:Space Flight; D014893:Weightlessness
vernacular_title: Contribution a l'etude des effets de l'apesanteur sur le systeme nerveux central du rat.