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Submaximal exercise‐induced increase of c‐Fos expression in the paraventricular nucleus of hypothalamus is related to the body heating rate
Author(s) -
Guimaraes Juliana Bohnen,
Rodovalho Gisele Vieira,
Wanner Samuel Penna,
Nascimento Kênia Fiaux,
Coimbra Cândido Celso
Publication year - 2011
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.25.1_supplement.1053.28
Subject(s) - hypothalamus , endocrinology , medicine , c fos , hyperthermia , thermoregulation , core (optical fiber) , chemistry , nucleus , heart rate , core temperature , physical exercise , gene expression , biology , neuroscience , blood pressure , materials science , biochemistry , gene , composite material
Exercise induced‐hyperthermia results from the imbalance between the rates of heat production and dissipation, and may determine performance. Anatomical and physiological evidence supports that the paraventricular nucleus of hypothalamus (PVN) is involved in central pathways modulating the sympathetic outflow to thermoregulatory effectors. However, it is unclear whether PVN is activated during the exercise in response to the increase in core temperature. We also verified if activation of the PVN by exercise through measurement of c‐Fos expression is related with thermoregulatory adjustments. Male Wistar rats were submitted to a submaximal exercise (18 m.min −1 ) until fatigue. Core and skin tail temperatures were measured and body heating rate was evaluated. Ninety minutes after the point of fatigue, animals were transcardially perfused. Brain was removed, cut in sections and processed immunohistochemically for c‐Fos. Exercise induced c‐Fos expression in the PVN and the number of labeled neurons was 140% higher than after rest situation. c‐Fos expression in the PVN was positively correlated with body heating rate (r=0.83, p < 0.001). Furthermore, body heating rate shows a tendency to negatively correlate with time to fatigue (r=0.71, p = 0.07). In conclusion, these results provide evidence that PVN is involved in thermoregulatory adjustments and can interfere with physical performance during exercise. Financial support: Capes, CNPq and Fapemig.