Circulating Insulin-Like Growth Factor I Mediates Effects of Exercise on the Brain

作者：Eva Carro, Ángel Núñez, Svetlana Busiguina, Ignacio Torres‐Alemán · 发表于：Journal of Neuroscience · 年份：2000 · DOI：10.1523/jneurosci.20-08-02926.2000 · 被引用次数：773 · 研究领域：Growth Hormone and Insulin-like Growth Factors、Neurogenesis and neuroplasticity mechanisms、Adipose Tissue and Metabolism

Physical exercise increases brain activity through mechanisms not yet known. We now report that in rats, running induces uptake of blood insulin-like growth factor I (IGF-I) by specific groups of neurons throughout the brain. Neurons accumulating IGF-I show increased spontaneous firing and a protracted increase in sensitivity to afferent stimulation. Furthermore, systemic injection of IGF-I mimicked the effects of exercise in the brain. Thus, brain uptake of IGF-I after either intracarotid injection or after exercise elicited the same pattern of neuronal accumulation of IGF-I, an identical widespread increase in neuronal c-Fos, and a similar stimulation of hippocampal brain-derived neurotrophic factor. When uptake of IGF-I by brain cells was blocked, the exercise-induced increase on c-Fos expression was also blocked. We conclude that serum IGF-I mediates activational effects of exercise in the brain. Thus, stimulation of the uptake of blood-borne IGF-I by nerve cells may lead to novel neuroprotective strategies.