Tonic control of subretrofacial vasomotor neurons in the rostral ventrolateral medulla

Abstract

1. Vasomotor pressor neurons in the subretrofacial nucleus of the rostral ventrolateral medulla receive afferent inputs from different sources that utilize different neurotransmitters. This paper briefly reviews recent studies on the role of inputs releasing: (i) GABA, and (ii) angiotensin II (AII) in the subretrofacial nucleus. 2. There are two types of tonic GABAergic inhibitory inputs: one arises from peripheral baroreceptors, while the second is independent of peripheral baroreceptors. 3. Blockade of receptors for AII elicits a decrease in blood pressure and sympathetic vasomotor activity, indicating that subretrofacial neurons are also tonically excited by AII. It is likely that the AII is released from nerve terminals in the subretrofacial nucleus, but the origin of the pathway is unknown.