ABSTRACT
This chapter describes the action of a selected example of psychoactive drugs, including marijuana; mushroom and cactus extracts with hallucinogenic properties, that is, psilocybin, psilocin, and mescaline; and the most astonishing drug of this group, Lysergic Acid Diethylamide. Serotonin is one of the major monoaminergic neurotransmitters in the brain. R. A. Glennon has suggested that the potency to induce hallucinations is directly proportional to the affinity for the serotonin receptor. Arachidonylethanolamide lipid is the biosynthetic product of arachidonic acid and ethanolamine and chemically is termed an eicosanoid. The original studies indicated that anandamide exists naturally in the porcine brain and binds to cannabinoid receptors. Psychedelic mushrooms are described as deities or gods. These mushrooms are in use in religious and ceremonial rituals of Mexican-Indian communities. The continuous use of psychedelic drugs since ancient times suggests that there is a human desire to self-impose drug-induced altered states of existence.
