Agonists serotonin, hallucinogens

The tetralins 18a and 18b were potent serotonin agonists in dog vascular smooth muscle (33) but did not elicit hallucinogen-like action in a conditioned avoidance response model in rats (156). However, 18b is a potent pyretic agent in rabbits and produces a rage response in cats (166). Addition of a double bond into the 3,4-position of the tetralins led to decreased serotonin-like action... 

LSD is not a specific serotonin antagonist but also exerts agonistic effects at serotonin receptors. On the other hand, many serotonin antagonists, which are more effective than LSD, are not hallucinogenic. 

Hallucinogens have rather complex interactions at neurotransmitter systems, but one of the most prominent is a common action as agonists at serotonin 2A (5HT2A) receptor sites (Fig. 13—10). Hallucinogens certainly have additional effects at other 5HT receptors (especially 3HT1A somatodendritic autoreceptors) and also at other neurotransmitter systems, especially norepinephrine and dopamine, but the relative importance of these other actions are less well known. Also, MDMA appears to be a powerful releaser of serotonin and it and several drugs structurally related to it... 

Hallucinogens are thought to have important actions as partial agonists at serotonin-2A receptors. True or False. 

Glennon RA, Young R, Rosecrans JA. Antagonism of the effects of the hallucinogen DOM and the purported serotonin agonist quipazine by 5-HT2 antagonists. Eur J Pharmacol 1983 91 189-196. 

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