serotonin is released from neurons of the raphe nuclei in the brain.
where is serotonin released from in the brain?
neurons of the raphe nuclei
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Na
central fatigue is a reduction in the neural drive or nerve-based motor command to working muscles that results in a decline in the force output. it has been suggested that the reduced neural drive during exercise may be a protective mechanism to prevent organ failure if the work was continued at the same intensity. there has been a great deal of interest in the role of serotonergic pathways for several years because its concentration in the brain increases with motor activity. during motor activity, serotonin released in synapses that contact motoneurons promotes muscle contraction. during high level of motor activity, the amount of serotonin released increases and a spillover occurs. serotonin binds to extrasynaptic receptors located on the axon initial segment of motoneurons with the result that nerve impulse initiation and thereby muscle contraction are inhibited.
muscle weakness