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

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. Acute sodium valproate (320 mg/kg, intraperitoneally) decreases the freuqncy 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). 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 raty behavior in the open-field, from the first to the fourtheenth day of th test. We conclude that the decreased novely-induced grooming does not depend on the opioid system and may be related to anti-anxiety effect of valproate

Effects of phenylethylamine on rat locomotor behavior and avoidance learning

1. The effects of ß-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-internal two-way avoidance acquisition. 2. The action of PEA was markedly different from that of aplhetamine 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 interation 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 tats while caroxazone had no effect. The association of the two drugs did not potenciate either