Changes in blood pressure and heart rate following bilateral olfactory bulbectomy in rats

Changes in blood pressure and heart rate following bilateral olfactory bulb ablation were investigated in unanesthetized and unrestrained rats with chronic arterial cannula implants. After bilateral olfactory bulbectomy, the rat exhibited a marked increase of emotional responses to given stimuli and a high incidence of muricide. Blood pressure and heart rate at 5 and 10 days after olfactory bulbectomy were significantly lower than in intact rats (rats before bulbectomy) and/or sham operated rats. Marked decreases in blood pressure and heart rate were seen especially in the period when the animals showed exploratory behavior after being transferred to the experimental cage from the home cage. These results suggest that olfactory bulbectomy has a great influence not only on emotionality but also on the central regulatory system of blood pressure in the rat.