While scientists had demonstrated that nerves outside of the brain communicate with muscles and organs via chemical messengers, there was little evidence to suggest that these chemical messengers were also used in the brain, and many scientists insisted that brain cells communicated only via electrical impulses.
In addition, at the time it wasn’t clear that chemicals played a role in transferring information between brain cells (neurons). As such, scientists thought it was a simple building block for the production of norepinephrine.
Dopamine bears a striking resemblance to another naturally occurring chemical prevalent throughout the nervous system, norepinephrine. While today it is recognized as a crucial part of brain function, scientists did not immediately recognize dopamine’s importance when it was first discovered in the brain in the early 1950s. Discovering dopamine’s role in Parkinson’s disease changed the field of neuroscience and led to a profound breakthrough in the treatment of the disease. Underestimated at its discovery, dopamine proved critical to central nervous system functions such as movement, pleasure, attention, mood, and motivation. Dopamine is a messenger molecule in the brain that allows certain nerve cells to communicate with one another.