read the textbook: Psychopharmacology By Metey & Quenzer 2nd Edition.
Please answer the discussion questions and Research fully.
Since marjuana exploded on the scene in the 1960s, it has gone through several changes, the most significant being the increased concentration (potency) of its active ingredient: delta-9 tetrahydrocannabinol (THC). Another significant advance was the discovery of endogenous cannabinoids, neurotransmitters that resemble THC that bind to specific receptors throughout the central nervous system. A third advance was the discovery of the cannabinoid receptor itself, present in numerous locations throughout the CNS. This is an example of how one must know neuroanatomy to understand the pharmacodynamics of a drug.
While there are many more cannabinoid receptors present in the CNS there are none present in the brainstem (pons and medulla) which control vital functions such as heartbeat and respiratory rate and function. Unlike opiate receptors which are numerous in the brainstem, the absence of cannabinoid receptors in the brainstem makes it virtually impossible to overdose on marijuana.
Hallucinogens can be classified based on either the neurotransmitters that are affected or by the class of drugs to which they are related. For instance, mescaline and MDMA (Ecstasy) are considered “amphetamine-like” hallucinogens because of their structural similarities to amphetamines. These drugs work primarily by affecting the neurotransmitter norepinephrine. On the other hand, LSD like agents (LSD and psilocybin) primarily exert their psychodynamic effect by influencing serotonin. A third class of drugs, atropine and scopolamine, affect the neurotransmitter acetylcholine.