No abstract

No abstract

No abstract

No abstract

No abstract

Learning/memory deficits in senescent animals are widely used as a tool to evaluate the therapeutic potential of agents for treatment of age-associated cognitive dysfunction. As assessed in the Morris water maze test, aged (21-24 months) rats showed a variable loss of spatial memory. Aged non-impaired rats performed as well as young subjects, while aged impaired rats exhibited a severe and persistent place-navigation deficit. Passive avoidance retention was similarly affected in the two aged subpopulations. Chronic oral administration of phosphatidylserine (50 mg/kg/day for up to 12 weeks), a pharmacologically active phospholipid, was found to improve both the spatial memory and the passive avoidance retention of aged impaired rats. Results are discussed with reference to the phosphatidylserine-induced improvement of age-associated deterioration of brain functions in rats.

In the framework of aggressive behavior a great amount of studies deal with altered brain monoamine levels or turnover. The involvement of brain serotonergic mechanisms in aggression has been demonstrated in the majority of the studies. In the present work, the biochemical and behavioral changes induced by prolonged socioenvironmental isolation in seven strains of mice were studied. Brain serotonin turnover varies significantly only in those strains which react to isolation with a constant degree of aggressiveness and there appears to exist an inverse correlation between these two parameters. Nevertheless a certain degree of aggression may develop even in the absence of alterations of brain serotonin turnover. Still the intensity of serotonin turnover decrease seems to represent a good indicator of the magnitude of the aggressive reaction.

No abstract