Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul (Oct 2002)
Role of brain Histaminergic system on the tail pinch-induced behavioral responses using brain microdialysis
Abstract
Background and Objective: This study was done to determine the role of brain histaminergic system on the tail pinch-induced behavioral responses. Methods: In male Albino Wistar rats (250-300 gr), microdialysis probes were implanted in the lateral ventricles under chloral hydrate anesthesia. (400 mg/kg i.p) by stereotaxy method. Rats were examined after recovery while Ringer solution (Ca++=2mM) perfused in implanted probes. Five min tail pinch was applied for control group. In sham group, Ringer solution was perfused via microdialysis probes while 5 tail pinch stress was performed. In both test groups, histamine (10µM) and promethazine (10µM) were added to the Ringer solution. Duration of these behavioral responses was recorded and sham and test group were compared with control and sham group, respectively. Variations were calculated depending on percentage and statistical analysis was done depending on absolute data. Student paired t-test and ANOVA were used for comparing within the same and different groups, respectively. Findings: According to the results, histamine increases duration of tail pinch induced behavioral response by 38±8% and promethazine as an antihistamine decreases it by 43±13%. Conclusion: The results showed that brain histaminergic system has a stimulating role on tail-pinch induced behavioral responses.