High salt intake has been shown to augment the sensitivity of rostral ventrolateral medulla (RVLM) sympatheoexcitatory neurons. We examined the effects of 4 weeks of high dietary salt (8%) on the sensitivity of nucleus tractus solitarius (NTS) and caudal ventrolateral medulla (CVLM) in controlling RVLM. In chloralose-anesthetized Sprague-Dawley rats, high salt intake did not elevate baseline arterial pressure or were greater. NTS responses to acetylcholine or serotonin, which is independent of baroreflex, also were greater. Phenylephrine or nitroprusside (i.v.) elicited similar changes in arterial pressure and heart rate, the baroreflex sensitivity also wa similar in both groups of rats. These results suggest that high salt intake augments the sensitivity of NTS and CVLM sending inhibitory input RVLM. This presumably may inhibiting the elevation of arterial pressure. [ABSTRACT FROM AUTHOR]