A runner’s high is a subjective sense of well-being some humans experience after prolonged exercise. For decades the hypothesis was that exercise-induced endorphin release is solely responsible for it. Recent evidence suggested may also play a role, which is a claim a mouse can settle and a person cannot.
Cannabinoid receptors, not opioid ones. Wheel running raised endocannabinoids in mice and reduced both anxiety and the sensation of pain. Removing from abolished the running-induced anxiolysis, and blocking central and peripheral cannabinoid receptors with drugs abolished the , so each half of the effect has its own handle.
A runner’s high is a subjective sense of well-being some humans experience after prolonged exercise. For decades, the hypothesis was that exercise-induced endorphin release is solely responsible for it, which is the version that reached popular fitness advice and stayed there.
Recent evidence had suggested that endocannabinoids may also play a role. Testing that requires removing a receptor rather than asking a question, which is why the experiment is done in mice.
The baseline result comes first. Wheel running increases endocannabinoids in mice, and reduces both anxiety and the sensation of pain, giving two measurable components to work with.
Then each component is knocked out separately. Ablation of cannabinoid receptor 1, one of the two cannabinoid receptors, on GABAergic neurons inhibits running-induced anxiolysis. Pharmacological blockage of central and peripheral cannabinoid receptors inhibits analgesia, which shows these receptors are crucial for main aspects of a runner’s high.
wat. Take away the cannabinoid receptor and the calm after the run goes with it.
wat wat
Deleting a receptor from one cell type is how a shared feeling becomes a named mechanism.
How do we know?
Fuss and colleagues measured endocannabinoids, anxiety and pain after wheel running in mice, then knocked out cannabinoid receptor 1 on specific neurons and separately blocked the receptors with drugs.
What is still unknown
Mice on wheels, with anxiety and pain measured by behavior rather than reported.
Learn something?
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