Figure 2: Chronic psychosocial stress caused elevation of blood pressure in normal animals and exacerbates existing hypertension in rat models of hypertension (spontaneous hypertensive rat “SHR” and obese Zucker rat). Note that treatment with 5-HT3 receptor antagonists, which block ganglionic LTP, inhibits the stress-induced component of hypertension. * and # indicate significant difference from the other two groups ( ).