Neurotransmitters are substances present in the body by which the neurons that make up the nervous system communicate. Neurotransmission occurs where individual neurons meet which is known as the synaptic junction. There are several known neurtransmitters and each of them has a specific function in the body. A deficiency or an excess in any of them has profound adverse effects on the human body particularly with regards to muscle coordination, neurocognitive function and behavior.
Dopamine is among the principal classic neurotransmitters that has a variety of function in the central nervous system. It has a monoamine structure and is classified as a cathecolamine like other neurotrasmitters such as norepinephrine and serotonin. Dopamine functions mainly as an inhibitory transmitter of CNS neurons. It plays an important role in regulating hypothalamohypophysial functions and several activities of the heart and the kidney.
When the dopaminergic neurons originating in the substantia nigra of the midbrain, is perturbed, a wide array of clinical disorders can be seen. These include Parkinson’s disease and some behavioral disorders like heroin addiction. It has been shown that the projection of dopaminergic neurons into the striatum can lead to Parkinson’s disease while the pathogenesis of heroin addiction is due to action of this drug on increasing dopamine release.
An understanding of the actions of neurotransmitters is very important in explaining and managing neurologic and behavioral disorders. In the case of dopamine other medical benefits have been elicited like in the treatment of shock and hypotension. For heroin addiction, using drugs that block the release and the effect of dopamine can leads to abolishing the effects of addiction. In contrast, the addition of dopamine-like drugs such as levodopa can be helpful in patients with Parkinson’s disease.