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Biomedical subjects

S Rouhani

Publications and source records attributed to S Rouhani.

9 recordsLinked to original sources

Effects of alcohol dependence on shock-induced fighting: action of muscimol and homotaurine.

We have applied the electroshock-induced fighting behavior to the study of experimental alcohol dependence. Adult Wistar rats were intoxicated chronically with ethanol (10 g/kg/24 h) for 13 days. Electroshock-induced fighting behavior was studied during chronic intoxication and withdrawal in comparison with normal rats receiving a water-carbohydrate solution isocaloric to ethanol. Rats were divided into groups receiving respectively muscimol (0.25 mg/kg), a GABAA agonist; homotaurine (140 mg/kg) a GABA mimetic; and physiological saline (10 ml/kg), intraperitoneally. During chronic intoxication, rats showed an increase in defensive-fighting behavior. Withdrawal accentuated the aggressive behavior and muscimol and homotaurine inhibited it. These results confirm the relevance of the electroshock-induced defensive fighting behavior test in chronic intoxication with alcohol, but to show the involvement of GABAergic transmission in the behavioral effects of alcohol withdrawal, additional experiments with other GABA mimetics and with GABA antagonists should be considered.

Aggression

Circadian variations in vigilance states in the alcohol-dependent rat.

Waking and sleep states were studied in the alcohol-dependent rat after administration of ethanol (416 mg/kg/hr) by indwelling intragastric catheter (IGC) for 13 days. Electropolygraphic recordings performed for a total of 24 hr from the start of withdrawal were compared with those of control rats receiving water by IGC and showed 1) that rapid eye movement sleep was the most sensitive of the four vigilance states studied. A decrease was noted both for the total duration of recording and for the light period; 2) that nonactive wakefulness was the only vigilance state to show an inversion of percentages between the light and dark period; 3) that the light period was the best time for studying changes in vigilance states. Changes included increased percentages of active and nonactive wakefulness and decreased percentages of slow-wave and rapid eye movement sleep. This was due to a change in the number of episodes rather to a change in their mean duration. No significant change occurred during the dark period.

Alcohol Withdrawal Delirium

The frequency of shifts between alternative equilibria.

We derive a formula giving the frequency with which random drift shifts a population between alternative equilibria. This formula is valid when such shifts are rare (Ns much greater than 1), and applies over a wide range of mutation rates. When the number of mutations entering the population is low (4 N mu much less than 1), the rate of stochastic shifts reduces to the product of the mutation rate and the probability of fixation of a single mutation. However, when many mutations enter the population in each generation (4 N mu much greater than 1), the rate is higher than would be expected if mutations were established independently, and converges to that given by a gaussian approximation. We apply recent results on bistable systems to extend this formula to the general multidimensional case. This gives an explicit expression for the frequency of stochastic shifts, which depends only on the equilibrium probability distribution near the saddle point separating the alternative stable states. The plausibility of theories of speciation through random drift are discussed in the light of these results.

Adaptation, Biological

Vigilance states and cerebral monoamine metabolism in experimental magnesium deficiency.

Correlations between cerebral monoamine metabolism and electrophysiological parameters were compared in 18 male Wistar rats subjected to a magnesium-restricted diet and in 14 normal rats. During the 40-day experimental period, plasma and erythrocyte Mg2+ levels and plasma Ca2+ and phosphorus levels were measured, and electroencephalographic tracings as well as clinical data were recorded at regular intervals. At the end of the study, the animals were killed and cerebral concentrations of monoamines and their metabolites were determined. Cerebral monoamine disorders characterized by a rise of dopamine and 5-hydroxyindole-3-acetic acid levels were observed in the magnesium-deficient group. This rise was accompanied by an increase in wakefulness and a decrease in sleep percent. The role played by magnesium in cerebral monoamine metabolism and sleep cycles is discussed.

3,4-Dihydroxyphenylacetic Acid

EEG effects of a single low dose of ethanol on afternoon sleep in the nonalcohol-dependent adult.

Three polygraphic recordings (PGR) of afternoon sleep (ANS) related to the duration of one sleep cycle, i.e., 90 min, were performed in 14 healthy adult volunteers (7 men and 7 women): two reference PGR, on two consecutive days (before ingestion of alcohol). Only the second being retained: reference PGR = P1; another recording, on day 3, 50 min after the start of single slow oral ingestion of the equivalent of 0.25 g 95% ethyl alcohol (ETOH) per kg body weight. Alcohol was ingested as 40 degrees whiskey, and the volume administered ranged from 34.5 to 66 ml (ETOH polygraphic recording = P2). Analysis of polygraphic traces was carried out according to the criteria of Rechtschaffen and Kales, and results were presented using the parameters adopted by Gross et al. (2). A single low dose of alcohol, leading to a low mean blood alcohol level (below 30 mg/100 ml, range 9 to 29 mg/100 ml), clearly perturbs sleep in the normal nonalcohol-dependent adult. In this context, ETOH does not appear to be a hypnotic since: a) the latencies to onset of sleep and the appearance of stages II, III, and IV of slow-wave sleep (SWS) are not shortened; b) the total duration of sleep, the percentage of delta sleep, and the duration (and percentage) of rapid eye movement sleep (REMS) are decreased; c) the number, duration, and percentages of intrasleep awakenings are increased, as are the number of stage changes. In addition, the study of afternoon sleep has shown itself to be a sensitive and reliable test for the analysis of the effects of a low dose of alcohol on nonalcohol-dependent subjects.

Adult