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Physical (In)activity dependent changes in the morphology of RVLM neurons
Author(s) -
Mischel Nicholas A,
Llewellyn-Smith Ida J,
Mueller Patrick 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.1091.54
Subject(s) - rostral ventrolateral medulla , brainstem , tyrosine hydroxylase , medicine , endocrinology , nucleus , immunohistochemistry , medulla oblongata , biology , anatomy , neuroscience , central nervous system
The rostral ventrolateral medulla (RVLM) contains neurons critical for cardiovascular regulation. Functional plasticity in RVLM neurons may contribute to increased sympathoexcitation in disease states. Here, we aimed to define morphological differences in RVLM cardiovascular neurons in sedentary vs physically active rats, hypothesizing that increased sympathoexcitation in sedentary rats would correlate with more dendritic branching. Physically active rats were provided with in‐cage running wheels for 14 weeks and ran 230 ± 81 km (n=4). We used immunohistochemistry for tyrosine hydroxylase (TH) in 150 μm brainstem sections and tracing software to reconstruct TH‐immunoreactive neurons at the caudal pole of the facial nucleus. Comparison of dendrites in 3 sedentary vs 4 active rats showed an average length of 1111±54 μm vs. 686±86 μm (p<0.05) and 9.7±0.7 branch nodes vs. 7.0±1.1 (p=0.058). A Sholl analysis showed 82±4.2 vs. 52.8±6.2 total intersections (p<0.05). These data suggest that greater dendritic branching in RVLM cardiovascular neurons contributes to increased sympathoexcitation and incidence of cardiovascular disease in sedentary individuals. (F30‐ HL105003 ; NHMRC 480414; R01‐ HL096787 ).