ROSTROVENTROLATERAL MEDULLA NEURONS PREFERENTIALLY PROJECT TO TARGET-SPECIFIED SYMPATHETIC PREGANGLIONIC NEURONS

Christopher J. Madden , Alan F. Sved. American Journal of Physiology - Heart and Circulatory PhysiologyPublished 1 December 2003Vol. 285no. H2734-H2748DOI: 10.1152/ajpheart.00155.2003. These studies investigated the role of C1 neurons in th RVLM in the control of BP. They injected DBH-saporin into the RVLM and waited 2 weeks. They found that MAP was 10mm Hg lower in rats with greater than 80% depletion of RVLM C1 neurons when compared to control injected group. As for baroreflex function, in the greater than 80% C1 depleted group that was attenuated gain in respone to sodium nitroprusside. In the smaller depleted group that was no difference in in baroreflex function when compared to the control group, A5 depleted group and Mabzap group. In response to hydralazine 80$ depleted C1 group has lower MAP when compared to groups that received control injections. As for catecholamine release in response to hydralazine was attenuated in the 80% depleted C1 group when compared to the control groups. In response to sciatic nerve stimulation the anti DBH group demonstrated attenuated responses when compared to all other groups. Bezold-Jarisch reflex, chemoreflex, and glutamate responses were not different between groups. From these studies they concluded that the C1 are playing a role in the tonic and reflex control of BP.-MD