Abstract
Background and Objectives: Nowadays, in study of psycho-body effects of stress, monoamine system of brain has gained special attention and known that stress cause behaviors which emerged by activating of monoamine systems including serotonergic system. The present investigation aimed to study the effects of brain serotonergic system on stress-induced behavioral responses.
Methods and Materials: Four groups of albino Wistar male rats (250-300g) were selected. Control group were exposed to tail pinch stress for 5 min. Tail pinch stress causes a variety of behavioral responses including gnawing, licking and aggression in rats. In the present study, duration of gnawing was measured. In other groups microdialysis probes were implanted in the raphe nucleus under cloral hydrate (500 mg/kg i.p) anaesthesia. In the sham group ringer solution was perfused (2µ mol/min) with tail pinch stresses (5min) that was performed. In the third group high concentration of potassium (100mM/Lite) was added in ringer solution and in the fourth group cadmium chloride substituted with calcium chloride and then exposed to stress. Stress-induced behavioral responses were measured like sham and exam groups.
Results: There was no significance difference in sham group compared with control group. Duration of behavioral response was decreased significantly in third group (p<0.001). But in fourth group behavioral response is which and compared with control and sham groups, showed significant increase (p<0.003).
Conclusion: Our result suggests that: brain serotonergic system in response of animal to stress and model of behavior response has inhibitory effect. Our results enhance previous information about monoamine system in process of stress and these results lead to specify of treating diseases caused by stress and avoiding the adverse effects of prescribed drugs.