Premium
Collateralizaton of projections of rostral ventrolateral medulla (RVLM) neurons to levels of the thoracic spinal cord that regulate upper‐ and lower‐body blood flow
Author(s) -
Gowen Michael F,
Weber Sarah A,
Suzuki Takeshi,
Sugiyama Yoichiro,
Yates Bill J
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1091.14
Subject(s) - rostral ventrolateral medulla , spinal cord , anatomy , medulla , central nervous system , blood flow , sympathetic nervous system , catecholaminergic , medulla oblongata , neuroscience , biology , medicine , chemistry , blood pressure , catecholamine
We have demonstrated that vestibular stimulation results in distinct changes in blood flow in the upper and lower body, indicating that the sympathetic nervous system has the capacity to elicit regionally‐specific changes in blood flow. Since the RVLM plays a major role in regulating blood flow, the present study tested the hypothesis that distinct populations of RVLM neurons project to the T4 segment (which controls blood flow in the upper body) and the T10 segment (which regulates lower body blood flow). For this purpose, multiple injections of the fluorescent dye Fast Blue were made in cats in the vicinity of the intermediolateral cell column (IML) in T4, whereas multiple injections of the dye Fluoro‐Ruby were made near the IML in T10. RVLM neurons that were single‐labeled for one of the tracers (indicating that they projected to only one segment) were approximately four times more prevalent than those that were double‐labeled (had collateralized projections to both T4 and T10), including catecholaminergic neurons identified through immunohistochemistry. A χ 2 test confirmed that double‐labeled cells were less prevalent than single‐labeled RVLM neurons (p<0.001). Our conclusion from these data is that the RVLM has the capacity to independently regulate sympathetic nervous system influences on blood flow in different body regions.