Effects of 2 hrs. restraint stress on brain serotonin metabolism and memory in rats

Stress is a non-specific response of body to any physiological and psychological demand. Studies on experimental animals show that uncontrollable stress situation produce neurochemical and behavioral deficits In the present study effects of 2 hrs. restraint stress were monitored on brain serotonin metabolism and memory in starved rats. An episode of 2 hrs. restraint stress exhibited a significant decrease in food intake as well as in growth rate in starved rats. The memory function was significantly enhanced following 2 hrs. restraint stress in starved rats. The concentration of Noradrenaline (NA) and Dihydroxyphenyl acetic acid (DOPAC) were increased in the brain while no effect of restraint stress was observed on brain Dopamine (DA) level. Brain levels of 5-hydroxy indoleacetic acid (5-HIAA) was significantly decreased in restraint rats. Tryptophan levels in brain as well as in plasma significantly decreased in starved rats following 2 hrs. restraint stress. The findings are explained in terms of enhanced memory function following restrained stress which may be associated with a decrease in serotonergic function in starved rats.