Erowid References Database
Bennett JP, Snyder SH.
“Serotonin synaptic receptors in the mammalian central nervous system”.
Federation Proc.. 1978;37(2):137-38.
Serotonin (5-HT) synaptic receptors (R) in the mammalian CNS are reviewed. 5-HT is demonstrable by microiontophoresis on neurons synthesizing the amine transmitter (auto-A) and neurons receiving the synaptic input of the transmitter (postaynaptic R). Exogenous application of 5-HT or d-LSD causes marked reduction in firing rate of midbrain raphe neurons or forebrain neurons receiving a 5-HT input from raphe nuclei. In rat forebrain membranes, d-3H-LSD is bound to SiteS that are not components of the presynaptic 5-HT system but appear to be associated with synaptic 5-HT function. 5-HT is the most effective displacing agent of d-3H-LSD binding. In rat and human brain, regional distribution of 3H-5-HT binding and d-3H-LSD binding are similar. Bound 3H5-HT is displaced potently by LSD analogs. 5-HT antagonists (methiothepin, cyproheptadine, methysergide. mianserin) are 4100 times more potent at displacing d-3H-LSD than 3H-5-HT binding. Neonatal intracerebral injection of 5-7,dihydroxytryptamine (40mcg) does not affect postnatal development of binding Sites for d-3H-LSD or 3H-5-HT. d-3H-LSD and 3H-5-HT binding are reduced in basal ganglia of Huntington's chorea patients and in rat striate unilaterally depleted of neurons. Most binding seems to occur to neurons, with binding Sites being independent of functional input from 5-HT neurons. 5-HT antagonists are more potent on d-3H-LSD compared to 3H-5 -HT binding Sites, and tryptamines with 5-OH substituents are more potent on 3H-5-HT than d-3H-LSD binding Sites. There appears to be a 2-state model for R functioning with d-LSD binding to both R conformations and with 5-HT binding primarily to the agonist conformation.
[ Cite HTML