Brain-derived neurotrophic factor in human cerebrospinal fluid is elevated after exercise.

Area of Science:

• Neuroscience
• Exercise Physiology
• Biochemistry

Background:

• Brain-derived neurotrophic factor (BDNF) is crucial for neuronal health and synaptic plasticity.
• Circulating BDNF is often used as a proxy for brain plasticity after exercise.
• BDNF levels in the cerebrospinal fluid (CSF) following exercise in humans remain unquantified.

Purpose of the Study:

• To investigate the impact of acute exercise on BDNF concentrations within the central nervous system.
• To quantify BDNF levels in the CSF and compare them with systemic circulation.
• To determine if there is a net release of BDNF from the brain following exercise.

Main Methods:

• Healthy participants underwent ~2 hours of cycling exercise.
• Total and free BDNF were measured in arterial and jugular venous blood.
• CSF BDNF was measured via lumbar puncture before and after exercise.

Main Results:

• Cerebrospinal fluid (CSF) BDNF concentrations significantly increased post-exercise.
• A net release of BDNF from the brain into systemic circulation was observed.
• CSF BDNF levels were orders of magnitude lower than systemic circulation.

Conclusions:

• Acute exercise elevates BDNF levels within the human brain's fluid compartment (CSF).
• The brain releases BDNF into circulation following exercise, despite lower CSF concentrations.
• These findings provide novel insights into exercise-induced neuroplasticity mechanisms.