The existence of circadian variations of apomorphine-induced stereotypy was determined. Male Wistar rats, standardized to a light-dark cycle (lights on from 7:00--19:00) for three weeks, were injected with apomorphine hydrochloride (1 mg/kg or 3 mg/kg) at one of six times (9:00, 13:00, 17:00, 21:00, 1:00 and 5:00). A significant time-of-day effect was found… (More)
The beta-adrenergic receptor-blocking drug, d,l-propranolol, was compared with placebo for relief of experimentally induced anxiety. Subjects were chosen on the basis of having high levels of trait anxiety. Stress was induced experimentally by two performance tests. Single 40-mg doses of propranolol significantly slowed the heart rate, suggesting a… (More)
Volunteer subjects were used to compare a potential antianxiety drug (nabilone, 2-mg single doses) with a standard drug (diazepam, 5-mg single doses). A double-masked design with placebo control was used. Volunteer subjects were selected on the basis of high levels of train anxiety and were tested by two anxiety-inducing procedures--the mirror drawing test… (More)
The subjects were 24 healthy males, 19 to 21 yr old. Twelve subjects had high neuroticism (HN) levels determined by Maudsley Personality Inventory, and 12 had low neuroticism (LN) levels. Subjects took a single 5-mg dose of diazepam (DZP) after a standardized breakfast. The mean plasma concentration for DZP was significantly higher in HN subjects at 1.5 hr… (More)
Mass fragmentography was used for quantitation of apomorphine in whole rat brain. Following extraction with 0.45 N perchloric acid, the components were derivatized to the O,O-bis(trimethylsilyl) (TMS) derivatives with N,O-bis(trimethylsilyl)trifluoroacetamide at 30 degrees C. The molecular ions of the TMS derivatives of apomorphine (m/z 411) and… (More)
Relationships between aging effects on apomorphine (AP)-induced stereotypy and AP concentrations in plasma and brain were studied in rats. In two separate behavioral studies, four groups of male Wistar rats (3, 6, 20, and 43 weeks of age) and two groups of female Wistar rats (5 and 35 weeks of age) were used, respectively: The former groups were… (More)
The relationship between the effect of food deprivation on apomorphine-induced stereotypy and the plasma apomorphine concentration in rats was studied. Male Wistar rats, allowed to have free access to food and water on deprived of food for 48 hr, were injected subcutaneously with apomorphine hydrochloride (10 mg/kg). Food deprivation was liable to… (More)
The stereotyped behavior induced by apomorphine in rats was inhibited by oxotremorine and tetrahydroaminoacridine (THA). 5-Hydroxytryptophan (5-HTP) did not change stereotypy scores. These data show influence of cholinergic mechanisms on such behavior. Possible clinical applications are discussed.