Interoceptive Information of Physical Vigor Through Circulating Insulin-Like Growth Factor 1.

ABSTRACT: The brain relies on interoceptive feedback signals to regulate bodily functions. Female mice with low serum IGF-1 levels (LID mice) exhibit reduced spontaneous running compared to control females, an effect not seen in males. Reduced activity normalized after sustained systemic IGF-1 treatment. This observation led us to hypothesize that circulating IGF-1-a key regulator of skeletal muscle and bone mass that crosses the blood-brain barrier during physical activity-may convey body vigor information to the brain. Since hypothalamic orexin neurons, which are involved in regulating physical activity, express IGF-1 receptors (IGF-1R) and are modulated by this growth factor, we hypothesized that these neurons might gauge circulating IGF-1 levels to modulate physical activity. Indeed, inactivatio

SUBMITTER: Zegarra-Valdivia JA 

PROVIDER: S-EPMC12793897 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature