Early Movement Restriction Affects FNDC5/Irisin and BDNF Levels in Rat Muscle and Brain

Area of Science:

• Neuroscience
• Developmental Biology
• Muscle Physiology

Background:

• Environmental interaction is crucial for sensorimotor and cognitive development.
• Sensorimotor restriction (SMR) in early life impairs motor behavior and brain organization in rats.
• The muscle-brain dialogue, particularly involving myokines like irisin, is not well understood in the context of SMR.

Purpose of the Study:

• To investigate the impact of SMR on the muscle-brain communication axis.
• To examine the expression of FNDC5/irisin in muscles and brain structures during SMR.
• To assess the relationship between irisin and Brain-Derived Neurotrophic Factor (BDNF) levels under SMR conditions.

Main Methods:

• Rats were subjected to sensorimotor restriction from postnatal day 1 (P1) to P28.
• FNDC5/irisin expression was measured in hindlimb muscles and brain regions using Western blotting.
• Irisin levels in blood and cerebrospinal fluid were quantified via ELISA.
• BDNF levels were assessed in brain structures.

Main Results:

• SMR led to increased FNDC5/irisin levels in the soleus muscle starting at P21.
• Altered FNDC5/irisin expression was observed in several brain structures as early as P15.
• BDNF levels showed an increase in the hippocampus at P8, with limited overall effects.

Conclusions:

• Sensorimotor restriction significantly impacts FNDC5/irisin levels in a specific postural muscle and various brain regions.
• SMR has a notable effect on the muscle-brain dialogue involving irisin.
• The study indicates limited effects of SMR on BDNF expression within the brain.