[citation needed] This part of the brain is responsible for basic survival instincts and reactions, for example to make an organism turn its head and look where an auditory stimulus was heard.
This response gets toxins and drugs out of the body by summoning control over motor neurons which stimulate muscles in the chest and thoracic diaphragm to expel contents from the stomach.
This is because the medulla oblongata is located in the area of the brain, the most inferior portion, which does not have a robust and highly developed blood-brain barrier.
These neurotransmitters implement their effects on the CTZ receptors by binding to them which sets off a chain of events that produces an action potential.
[5] The vomiting center of the brain refers to the groups of loosely organized neurons in the medulla that include the CTZ within the area postrema and the nucleus tractus solitarii.
[6] Dopamine and serotonin have been found to play the biggest role in communication from the CTZ to the remainder of the vomiting center, as well as histamine.
[6] Chemoreceptors in the CTZ relay information about the presence of emetic agents in the blood to the adjacent nucleus tractus solitarii (NTS).
The main neurotransmitters involved in communication between the CTZ and remaining vomiting center are serotonin, dopamine, histamine, and endogenous opioids which include endorphins, enkephalins, dynorphin.
Some classes of molecules have been shown to inhibit the emetic response due to histamine, these include mepyramine, burimamide and metiamide.
[9] The PDE4 degrades the phosphodiester bonds in the second messenger molecule cyclic adenosine monophosphate (cAMP), which is one of the ways the brain relays information.
[10] Since the neurons in the CTZ convey information relating to emesis to the other parts of the vomiting center, it was thought that these H-channels might play a role in nausea and the emetic response.
It has been found that ZD7288, which is a H-channel inhibitor, inhibited the acquisition of conditioned taste aversion (CTA) in rats and reduced apomorphine-induced c-Fos expression in the area postrema where the CTZ is located.
[10] This suggests that the neurons that express H-channels in the CTZ and area postrema are involved in nausea and the emetic response.
Most of these work by not allowing certain blood-borne drugs (usually pain killers or stimulants) to bind to their respective receptors located in the CTZ.
Other antiemetic medications work similarly by lowering a different substance in the brain that is known to interact with chemoreceptors in the CTZ that cause emesis.
This way, the patient does not have to worry about the doctors prescription to treat their pain causing them to be in severe discomfort via vomiting.