Glutamate receptor
Glutamate receptors are synaptic and non synaptic receptors located primarily on the membranes of neuronal and glial cells. Glutamate (the conjugate base of glutamic acid) is abundant in the human body, but particularly in the nervous system and especially prominent in the human brain where it is the body's most prominent neurotransmitter, the brain's main excitatory neurotransmitter, and also the precursor for GABA, the brain's main inhibitory neurotransmitter. Glutamate receptors are responsible for the glutamate-mediated postsynaptic excitation of neural cells, and are important for neural communication, memory formation, learning, and regulation.
Arvid Carlsson
In 1957 Kathleen Montagu demonstrated the presence of dopamine in the human brain; later that same year Carlsson also demonstrated that dopamine was a neurotransmitter in the brain and not just a precursor for norepinephrine. Carlsson went on to develop a method for measuring the amount of dopamine in brain tissues. He found that dopamine levels in the basal ganglia, a brain area important for movement, were particularly high. He then showed that giving animals the drug reserpine caused a decrease in dopamine levels and a loss of movement control. These effects were similar to the symptoms of Parkinson's disease. By administering to these animals L-Dopa, which is the precursor of dopamine, he could alleviate the symptoms. These findings led other doctors to try using L-Dopa in patients with Parkinson's disease, and it was found to alleviate some of the symptoms in the early stages of the disease. L-Dopa is still the basis for most commonly used means of treating Parkinson's disease.