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Biomedical subjects

R Chiş

Publications and source records attributed to R Chiş.

6 recordsLinked to original sources
PubMedDate not supplied

The influence of auditory and lithium stimulation on blood and brain serotonin in the normal rat and in that susceptible to audiogenic convulsions.

Investigations were carried out in two groups of male rats: a group susceptible to audiogenic convulsions and a control group. The following parameters were determined under basal conditions and 24 and 48 hours after intraperitoneal administration of a single lithium carbonate dose (0.67 mEq/animal), before and after auditory stimulation: serotonin content in the blood and brain tissue (separately from the hypothalamus, rhinencephalon, midbrain and sensory-motor cerebral cortex) by fluorimetry: water-saline retention, renal potassium elimination, the dynamics of renal lithium elimination. The results showed that in the rats prone to audiogenic convulsions, blood serotonin concentrations are twice those in the controls, whereas serotonin levels in the brain are lower than in the controls. The administration of lithium is followed by a decrease in blood serotonin in the animals with audiogenic convulsions but does not influence the serotonin content in the brain. Acoustic stimulation does not influence the behaviour of the controls but induces convulsions in the animals sensitive to noise. After auditory stimulation under basal conditions or 48 hours after the administration of lithium a decrease takes place in cerebral serotonin and an increase in blood serotonin in the controls whereas in the rats sensitive to noise, cerebral serotonin increases and blood serotonin decreases on stimulation under basal conditions due to the convulsions and metabolic alterations induced by the latter. These findings suggest the existence of different mechanisms for the transport of serotonin in the blood of rats prone to audiogenic convulsions. These mechanisms may be influenced either by acid catabolites resulting from convulsive activity or by the administration of lithium. The latter may induce persistent alterations in the blood transporter, as appears to result from the observation at 48 hours after the administration of lithium.

Acoustic Stimulation↗
PubMedDate not supplied

EEG automatic processing method.

This is a description of researches carried out in man and experimentally in rats. The results - obtained in 44 children aged between 12 and 14 yr. - of the electric signal processed as a F/A ratio were compared to the transport mechanisms of the blood sodium. We found that the normal brain excitability level was consistent only with the blood sodium transport through interaction with the proteins. The lack of such interaction was accompanied by an increased excitability on eeg recordings and by behaviour disturbances. The researches carried out in rats had in view the brain excitability level in two groups of animals aged 6-8 months, which drank from their birth either physiological salt (group 1) or distilled water (group 2). In this species, in spite of direct visible modifications in eeg recordings by sensorial stimulation, the processing as F/A ratio did not show any differences, and this made necessary the use of computers to process rightly the data; the respective digitization and memorising methods are described, too.

Adolescent↗