Perhaps there is more to learn. Chemical changes are, indeed, important. Changing neurons with caffeine is not a casual observation, it has deep implications. The complexity of voluntary movement has been linked to coordinated activity of motor neurons and action potential activity to premotor neuronal networks in the spinal cord or higher motor areas in the motor cortex. The 1998 Nobel Prize in Physiology or Medicine recognized the biological significance of nitric oxide.
Nitric oxide is derived from the amino acid arginine.
Nitric oxide acts as a neurotransmitter and can modulate many neurological reactions. The immune system uses nitric oxide to destroy pathogens by interfering with key enzymes. Nitric oxide is responsible for both osteoclastic and osteoblastic responses in bone and is a key player in the degenerative aspects of arthritis. The process of apoptosis employs nitric oxide in the orderly removal of unneeded cells. There is clear evidence that major signaling and control mechanisms exist in the body apart from the nervous system.