electrical stimulation effect of the horizontal limb of diagonal band of Broca on blood pressure and heart rate of rats

ABSTRACT

It has already been shown that diagonal band of broca has a regulatory effect on cardiovascular system. In this study we electrically stimulated the horizontal limb of the diagonal band of broca [hDB] to find its effect on blood pressure and heart rate. In this experimental study 34 rats were anesthetized with urethane and hDB was stimulated [80-150 microamperes for 15 sec] by a silver electrode coated with glass except for its tip. Blood pressure and heart rate were continuously recorded by a computer. Paired t-test was used for comparison of the prestimulation data and the maximum changes after the stimulation. The results showed that electrical stimulation caused a significant decrease in blood pressure and heart rate. The maximum changes for long-term responses were 9.39 +/- 1.13 mmHg for mean blood pressure and 15.4 +/- 3.19 for heart rate. For short-term responses the maximum changes were 9.08 +/- 1.4 mmHg for mean blood pressure and 7.5 +/- 2.36 for heart rate. It is possible that glutaminergic system of the hDB suppresses the vasopressin release from hypothalamus, thereby decreasing the blood pressure, and suppresses the sympathetic flow to the heart, thereby decreasing the heart rate