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Immunofluorescence identifies the α1 subunit of the GABA A receptor on spinally projecting neurons in rostral ventrolateral medulla
Author(s) -
Dombrowski Maryetta Donna,
LlewellynSmith Ida J,
Mueller Patrick J
Publication year - 2013
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.27.1_supplement.1118.25
Subject(s) - rostral ventrolateral medulla , spinal cord , medulla oblongata , receptor , medulla , inhibitory postsynaptic potential , medicine , chemistry , protein subunit , endocrinology , biology , neuroscience , central nervous system , biochemistry , gene
The rostral ventrolateral medulla (RVLM) is important for sympathetic control of the cardiovascular system. RVLM neurons are known to be under strong tonic γ‐amino‐butyric acid (GABA)‐ mediated inhibition, presumably due to activation of GABA A receptors. This investigation aimed to demonstrate that GABA A receptors are present on spinally projecting RVLM neurons. Male Sprague‐Dawley rats were injected bilaterally with cholera toxin B (CTB) at spinal cord segment T9/T10. Double immunofluorescent labeling identified immunoreactivity for CTB (green, FITC) and the GABA A α1 receptor subunit (red, Cy3) in RVLM. Of 179 CTB‐immunoreactive RVLM neurons (n=4 rats), 176 (98.3%; range among rats, 95.9–99.1%) contained immunoreactivity for the GABA Aα1 receptor subunit. Our data show that virtually all bulbospinal RVLM neurons express GABA Aα1 . These anatomical observations support the involvement of RVLM GABA A receptors in inhibitory control of sympathetic outflow arising from the lower thoracic spinal cord. (R01‐HL096787‐S1; NHMRC 1025031; R01‐ HL096787).