The improvement of exercise performance by physical training is related to increased hypothalamic neuronal activation.
Clin Exp Pharmacol Physiol
; 43(1): 116-24, 2016 Jan.
Article
em En
| MEDLINE
| ID: mdl-26475529
ABSTRACT
The effects of physical training on hypothalamic activation after exercise and their relationship with heat dissipation were investigated. Following 8 weeks of physical training, trained (TR, n = 9) and untrained (UN, n = 8) Wistar rats were submitted to a regimen of incremental running until fatigue while body and tail temperatures were recorded. After exercise, hypothalamic c-Fos immunohistochemistry analysis was performed. The workload, body-heating rate, heat storage and body temperature threshold for cutaneous vasodilation were calculated. Physical training increased the number of c-Fos immunoreactive neurons in the paraventricular, medial preoptic and median preoptic nucleus by 112%, 90% and 65% (P < 0.01) after exercise, respectively. In these hypothalamic regions, increased neuronal activation was directly associated with the increased workload performed by TR animals (P < 0.01). Moreover, a reduction of 0.6°C in the body temperature threshold for cutaneous vasodilation was shown by TR animals (P < 0.01). This reduction was possibly responsible for the lower body-heating rate (0.019 ± 0.002°C/min, TR vs 0.030 ± 0.005°C/min, UN, P < 0.05) and the decreased ratio between heat storage and the workload performed by TR animals (18.18 ± 1.65 cal/kg, TR vs 31.38 ± 5.35 cal/kg, UN, P < 0.05). The data indicate that physical training enhances hypothalamic neuronal activation during exercise. This enhancement is the central adaptation relating to better physical performance, characterized by a lower ratio of heat stored to workload performed, due to improved heat dissipation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Condicionamento Físico Animal
/
Hipotálamo
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Clin Exp Pharmacol Physiol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Brasil