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Biomedical subjects

G I Gorgiladze

Publications and source records attributed to G I Gorgiladze.

At least 19 recordsLinked to original sources
PubMed2004

Electrical stimulation of labyrinths and vestibular reactions.

Stimulation of the labyrinth in rabbits and guinea pigs with ascending (cathode) or descending direct current (anode) induced deviation and nystagmus of the eyes, head turn and tilt, and other reactions. Anodization of both labyrinths was followed by the disappearance of reflexes, suppression of vestibular reactions to adequate stimulation, and loss of swimming ability. The state of animals returned to normal after breaking the electric circuit.

Animals↗
PubMed2003

[The effect of microgravity on the state of compensation in one-side labyrinthisized newts].

Experiments were performed on newts Pleurodeles waltii subjected to one-side labyrinthectomy 1, 2, 5, and 6 mos prior to a spaceflight on board the orbital complex Mir. Duration of the exposure in microgravity was 8, 31 and 73 days. Destruction of one labyrinth in the newts brought about a number of characteristic reactions, i.e. rollover, circling and sideway movements with the head on a solid substrate and spinning about the longitudinal body axis when in water. These reactions were directed exclusively towards the labyrinthectomized side, their intensity faded, and typically in 1.5 mos. following surgery the motor activity of the newts was close to the norm. In the weight-free conditions the animals appeared to lose compensation they had formed on Earth. During 1.5 days of return the newts were unable to walk and their heads were turned towards the labyrinthectomized side. Immersed in water, the animals started spinning also towards this side. Two days later, they regained the ability to walk without assistance but with evident signs of ataxia. In 40 days after flight, the animals still exhibited locomotor disturbances during walk and swimming.

Adaptation, Physiological↗
PubMed2002

Effect of static and dynamic influences on receptors of equilibrium organ of Helix lucorum after 163-day orbital flight in "Mir" station.

A 163-day orbital flight increased the baseline impulse activity of statocyst receptor cells in terrestrial pulmonata snail Helix lucorum. The maximum of reaction to step static stimuli (changes in body position in the range from 0 to 180 degrees) was significantly shifted by 30 degrees from gravitational vertical, while the reaction to dynamic stimuli (dumped sinusoidal oscillations) faded more rapidly than in control animals.

Animals↗
PubMed2002

[Electrophysiological characteristics of the statocyst receptor cells in snails Helix lucorum following exposure to microgravity in unmanned spacecraft "Foton" and piloted space station "Mir"].

Following 16-, 53-, 73- and 163-d orbiting, the background pulsation of the statocyst receptor cells (statoreceptors), the equilibrium organ in land pulmonary snails Helix lucorum, was found increased. Alteration of the body spatial position (2-min tilt at 90 degrees toward the upsilateral side) in the space-flown snails was noted to occur with delayed dying away of the pulsation rate. During stepwise (30 degrees) tilts in the range from 0 to 180 degrees, the maximum of the reaction was shifted by 30 degrees from the gravitational vertical; during dynamic tilting (sine decaying oscillations) the reaction subsides more rapidly as compared with the control animals. Absence of changes in pulsation of receptor cells in statocysts deprived of feedback with the nervous centers may be suggestive of inactivation of the efferent innervation in consequence of exposure to microgravity.

Animals↗
PubMed1983

Space motion sickness: phenomenology, countermeasures, and mechanisms.

A summary of the incidence of Space Motion Sickness (SMS) in 27 Soviet cosmonauts who flew on missions varying from 2-185 d in the Salyut-6/Soyuz vehicle complex is presented. A questionnaire indicated that 88% (24) of the cosmonauts developed some type of "illusionary sensations" while 44% (12) presented some degree of SMS. The SMS countermeasures used in flight included an antihistaminic drug, pneumatic cuffs applied to the thigh region, application of lower body negative pressure, a head cap that restricted head movement while simultaneously providing force stimulus to the cervical antigravity muscles, and finally the use of an insole counterpressure device that added pressure to the sole of the foot.

Humans↗
PubMed1979

["Phenomenon" of vestibular compensation].

The role of spinal afferentation from the lower part of the body in establishing compensation of the consequences of the vestibular function abaissement was studied in experiments on guinea pigs. The ligation of the spinal cord at the level of thoracic segements performed under local anesthesia neither produced appreciable effect on the compensatory development at simultaneous or subsequent destruction of the labyrinth nor destroyed it in the preliminarily labyrinthectomized animals. The ligation of the spinal cord in the labyrinthectomized animals under ether or chloroform anesthesia was accompanied by a strong disorder of the compensation. The above substances also provoked analogous decompensation in the unilaterally labyrinthectomized animals with an intact spinal cord. The results obtained indicate that the reported disorder of the vestibular compensation induced by ligation of the spinal cord under ether anesthesia is consequent on an immediate effect of inhalation anesthetics on the compensatory mechanisms rather than is resultant of abolishing spinal afferentation from the lower part of the body.

Adaptation, Physiological↗
PubMed1978

[Compensatory processes during unilateral loss of vestibular function].

Changes in the compensation of the sequences of the unilateral loss of the labyrinthine function were studied in rabbits. Destruction of the labyrinth was accompanied by ocular nystagmus, increase of frequency of respiration and heart contractions, and EEG-activation. Investigations carried out showed these reactions to be extinguished at different time. At the late periods of labyrinthectomy a considerable asymmetry of nystagmus reaction to the angular accelerations equal in intensity, but opposite in direction was revealed. Stimulation of an intact otolith labyrinth was accompanied by the appearance of positional nystagmus. The results obtained indicated imperfection of the compensatory mechanisms during complete unilateral loss of the vestibular function.

Animals↗
PubMed1977

[Assessment of the role of the sensory innervation of the intraocular muscles in habituation of vestibulo-oculomotor reactions].

In rabbits, participation of the extraocular muscles' sensitive innervation in extinguishing of the eyes nystagmus elicited by periodical rotations, was studied. Either limitation or complete abolishing of the above muscles motor activity were used, as well as the passive forced movements of the eyes. No considerable difference was revealed between the intact and the experimental animals. In both cases the course of nystagmus extinguishing was the same. On the other hand, repeated forced movements of the eye had no effect on the reflectory evoked nystagmus. The data obtained suggest that the proprioceptive afferents of the extraocular muscles take no part in the habituation of vestibular-oculomotor responses.

Animals↗