Biomedical subjects

M Tannhauser

Publications and source records attributed to M Tannhauser.

13 recordsLinked to original sources

PubMed1992

Effect of sodium valproate on the open-field behavior of rats.

1. It has been reported that sodium valproate induces a morphine-like withdrawal syndrome in rats. The effects of acute or chronic treatment with sodium valproate on rat behavior was studied in the open-field test. 2. Acute sodium valproate (320 mg/kg, intraperitoneally) decreases the frequency of, and the time spent in grooming even when not modifying locomotion, rearing or defecation (N = 15), either 15 or 60 min after an acute treatment. This effect was not modified (N = 10) by concomitant administration of morphine (2 mg/kg) or naloxone (1 mg/kg). 3. Interruption of prolonged (30 days) valproate treatment with increasing doses of 40 to 320 mg/kg, by gavage, twice daily (N = 10) did not modify rat behavior in the open-field, from the first to the fourteenth day of the test. 4. We conclude that the decreased novelty-induced grooming does not depend on the opioid system and may be related to an anti-anxiety effect of valproate.

Animals↗

PubMed1991

Enhanced detection of hyperactivity after drug withdrawal with a simple modification of the open-field apparatus.

The open-field apparatus has been used to study withdrawal reactions from chronic treatments with central nervous system depressant drugs. To study the behavior of the same animal after drug withdrawal, the rats are introduced into the open field on consecutive days. Because the open field is a novel environment, the repetition could lead to false-negative results with regard to drug withdrawal. To overcome this problem, we sought a modification of the open field, using different floor-painting patterns every time the animal is observed. The most frequently observed withdrawal manifestation was hyperactivity. We verified that long-term treatment withdrawal reactions from barbital, clonazepam, and ethanol were seen more often if the rats were introduced in the modified open field. In addition, fewer animals were used here than in other trials and hyperactivity was detected more frequently in the modified open field than was sound-induced convulsions. We propose that the modified open field is more useful than the classic one for screening of drug withdrawal reactions.

Animals↗

PubMed1990

Lack of tolerance to imipramine or mianserine in two animal models of depression.

Few clinical reports describe tolerance induced by antidepressants and this question is considered an unsolved problem for clinical use of this group of drugs. The present report deals with the effects of imipramine and mianserine on two animal models of depression, after acute or prolonged previous treatment with these antidepressants. Imipramine and mianserine potentiated amphetamine-induced anorexia both after acute administration or after prolonged previous treatment with each drug. Mianserine effects were not detected in the behavioral despair test and imipramine reduced rats immobility equally after acute and prolonged previous treatment. It was concluded that imipramine and mianserine do not induce detectable tolerance when previously administered to animals submitted to amphetamine anorexia or behavioral despair.

Amphetamine↗

PubMed1989

Effects of phenylethylamine on rat locomotor behavior and avoidance learning.

1. The effects of beta-phenylethylamine (PEA) alone and in association with caroxazone, a potent inhibitor of monoamine oxidase B (MAO B), on the activity and long-term memory in the wheel-shaped activity monitor and on fixed-interval two-way avoidance acquisition were studied in rats. In a separate study, we determined the effects of PEA and of d-amphetamine on the variable-interval two-way avoidance acquisition. 2. The action of PEA was markedly different from that of amphetamine in several aspects. The stimulating effects of PEA in the wheel-shaped activity monitor were of a more subtle nature than those of amphetamine and in the variable-interval two-way avoidance acquisition PEA had no effect, while amphetamine improved performance. 3. PEA did not induce an increase in path-choice stereotypy, but caroxazone did. The absence of any caroxazone-session interaction effects on the path iteration frequency suggested that there were no long-term memory effects. 4. In the fixed-interval two-way avoidance acquisition experiments, PEA increased the avoidance responses of rats while caroxazone had no effect. The association of the two drugs did not potentiate either.

Animals↗

PubMed1984

Effects of carbamazepine or imipramine alone or in association with amphetamine on the fighting time of REM sleep-deprived rats.

The fighting time of REM sleep-deprived rats was measured after both acute and long-term intraperitoneal treatment with carbamazepine (CBZ) or imipramine (IMI) alone or associated with amphetamine. Fighting time was increased by the lower doses of CBZ (5-20 mg/kg) or IMI (0.5-2 mg/kg) administered acutely. At the highest dose tested, CBZ (40 mg/kg) was not significantly different from the control value, and the fighting time observed after 4 mg/kg IMI was less than that observed with 2 mg/kg. Amphetamine (2 mg/kg) alone increased the fighting time and this effect was not modified by association with 5-40 mg/kg CBZ or 0.5-4 mg/kg IMI. Long-term treatment (14 days) with CBZ (20 mg kg-1 day-1) or IMI (2 mg kg-1 day-1) significantly reduced fighting time in contrast to the increase observed with a single acute treatment at the same dose. The fighting time of rats acutely treated with amphetamine (2 mg/kg) was significantly but not completely reduced by previous long-term pretreatment with CBZ, whereas IMI pretreatment had no effect. The differences between the effects of acute and long-term treatment with CBZ cannot be explained by the development of metabolic tolerance, since serum CBZ levels were the same in both situations.

Aggression↗

PubMed1982

Carbamazepine-induced hyperglycemia in hyponatremic rats.

Hyponatremia was induced by intraperitoneal administration of 5.5% glucose followed by treatment with carbamazepine. Serum determinations of carbamazepine were also performed. Carbamazepine decreased serum Na+ and increased blood glucose concentration in the hyponatremic rats.

Animals↗

PubMed1981