Scopolamine degrades spatial working memory but spares spatial reference memory: dissimilarity of anticholinergic effect and restriction of distal visual cues.

The influence of the centrally active anticholinergic, scopolamine hydrobromide, on working and reference memory was studied in rats tested in a 12-arm radial maze. Both 0.25 and 0.

Antidepressant treatment of children: clinical relapse is unrelated to tricyclic plasma concentrations.

Plasma concentrations of imipramine and amitriptyline and their desmethylated metabolites were measured in 20 children being treated for major depressive illness 2 wk. and 5 to 10 wk. after achieving drug dosages of 2.

Sensory and social influences on ice cream consumption by males and females in a laboratory setting.

Both male and female undergraduates ate more ice cream when eating occurred in groups of three or four than when they ate alone. These subjects also ate more ice cream when offered three different flavors than when offered only one flavor of their own choosing. For women, both variety and eating in a group combined to enhance eating more than either variable did alone.

Spatial memory of children and adults assessed in the radial maze.

To assess the development of accurate spatial memory and its relationship to organized search strategies, children (18-71 months old) and college students searched for rewards hidden at the ends of the arms of an eight-arm radial maze. Subjects made their first four choices in random order selected by the experimenter (forced choice) or in whatever order they wished (free choice). In some conditions, a retention interval was imposed between arm choices 4 and 5, followed by a resumption of the task.

Preservation of accurate spatial memory in aged rats.

Male rats were tested in an 8 arm radial maze from 6-26 months of age with 5 hr delay imposed between choices 4 and 5. At 26 months their spatial memory was more accurate than when they were first tested at 6 months and also more accurate than that exhibited by another 5 month old group tested concurrently. However, these old rats acquired a noval spatial habit more slowly than the younger animals.

Amphetamine disrupts both working and reference memories of rats trained in a radial maze.

To assess the effects of amphetamine on working and reference memory rats were trained on a 12-arm radial maze with six arms baited and six arms unbaited until stable performance was achieved. Administration of 2.0 mg/kg d-amphetamine sulfate increased both working and reference memory errors, but only if a 5-min delay was imposed after three successful choices.

Comparative effects of long-term ethanol consumption and forebrain lesions on maze learning and active avoidance behavior in rats.

Male rats consumed a liquid diet containing 10.7% ethanol as their only source of food and fluid for 6.5 months, beginning at 2 months of age.

Suppression of play fighting by amphetamine: effects of catecholamine antagonists, agonists and synthesis inhibitors.

Moderate doses of amphetamine and methylphenidate profoundly depress play fighting in juvenile rats. To test the idea that this behavioral effect was dependent on the release of catecholamines (CAs) we administered haloperidol (0.05-0.

Spatial memory over long retention intervals: nonmemorial factors are not necessary for accurate performance on the radial-arm maze by rats.

A. Markowska, O. Buresová, and J.

Opiate antagonists, morphine and spatial memory in rats.

To assess the possible role of endogenous opioids on spatial memory, rats were administered morphine (1-15 mg/kg), naloxone (1-10 mg/kg), or naltrexone (0.1-10 mg/kg) at varying times after or prior to completing the first 4 choices in an 8 arm radial maze. None of these agents consistently affected retention, suggesting that endogenous opioid systems do not play a major role in modulating neural mechanisms that maintain accurate spatial memory.

Medial hypothalamic lesions and play fighting in juvenile rats.

The effects of medial preoptic area (MPOA), anterior hypothalamic (AH) and ventromedial hypothalamic (VMH) lesions on play fighting were studied in juvenile rats that were housed and observed in heterosexual groups of 6-8 animals. Overall males engaged in play fighting more frequently than females and none of the lesions reliably affected this measure. Males also initiated more play fights.

Olfactory bulbectomy and play fighting in juvenile rats.

To determine the influence on play fighting of inputs to the brain that arise in or course through the olfactory bulbs juvenile male and female rats were bilaterally bulbectomized at 23 or 24 days of age. The frequency of play fighting and play initiation was observed in tests conducted in the home cage. Bulbectomy did not affect the frequency of play fighting or play initiation by males, but slightly increased the frequency of play fighting without altering play initiation in females.

Retention deficit after d-amphetamine treatment: memory defect or performance change?

Retention deficits in discrete trial delayed alternation and delayed matching to sample tasks following administration of d-amphetamine have been interpreted to support the view that arousal facilitates the decay of information from shortterm memory (STM) (Kesner, 1973). But since amphetamine causes numerous changes in performance, alternative explanations of the deficit are also plausible. In an attempt to separate drug effects on memory from those on performance, the effects of d-amphetamine on spatial memory in the radial maze were studied in rats.

Spatial working memory in rats: effects of monoaminergic antagonists.

To assess the possible involvement of the monoaminergic neurotransmitters norepinephrine, dopamine and serotonin in the maintenance of spatial working memory rats were treated with antagonists 0 or 2 hr after completing the first 4 choices in an 8 arm maze. Haloperidol (0.25-1 mg/kg), when administered 2 hr after Choice 4, produced a small but consistent impairment in performance on retention tests given 5 hr after the first 4 choices.