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Origin of Catecholamine Afferents to Rat Rostral Ventrolateral Medulla (RVLM)
Author(s) -
McCloskey Colin,
Sved Judith C.,
Sved Alan F.,
Card J. Patrick
Publication year - 2007
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.21.5.a474-b
Subject(s) - rostral ventrolateral medulla , area postrema , catecholamine , catecholaminergic , catecholaminergic cell groups , brainstem , medulla oblongata , locus coeruleus , adrenergic neurons , neuroscience , tyrosine hydroxylase , biology , chemistry , medicine , endocrinology , anatomy , central nervous system , dopamine , adrenergic , receptor
The RVLM plays an important role in the central control of cardiovascular function. Although previous studies have reported that catecholamine neurons in A1, A5, area postrema, and the locus coeruleus innervate rat RVLM, the contributions of each of these cell groups to this innervation are not known. We addressed this question using retrograde tracing and fluorescence immunocytochemistry. Adult male rats were killed seven days after injection of the beta subunit of cholera toxin (CTb) into RVLM and processed for dual localization of CTb and tyrosine hydroxylase (TH). CTb labeled neurons were present in all areas known to project to RVLM, including neurons in the A1 area, the dorsal vagal complex (DVC), the contralateral RVLM, and the A5 area. Dual localization of CTb and TH demonstrated that the commissural projection to the contralateral RVLM arises principally from non‐catecholamine neurons. Additionally, labeling in A1, A5, and the DVC demonstrated that RVLM afferents arise from only a subset of catecholamine neurons in each region. Additionally, retrograde labeling of non‐catecholaminergic neurons was also observed in A1, A2, and A5 areas. These data suggest functional heterogeneity of the catecholamine cell groups. ( RRO18604 , HL55786, HL76312)