The newly synthesized compound and putative 5-HT2 antagonist ritanserin, but not the structurally related compound R 56413, resembles pirenperone in that it acts as a pure antagonist in an LSD-saline drug discrimination assay in the rat. Ritanserin exceeded pirenperone in terms of behavioral specificity; the lowest effective dose of ritanserin in antagonizing LSD was one order of magnitude...
125I-Lysergic acid diethylamide (125I-LSD) is the first 125I-labeled ligand for serotonin receptor studies. Its binding to rat frontal cortex membranes is saturable, reversible, and stereospecific. Specific binding is linearly dependent on tissue concentration and represents 70-80% of the total binding. Scatchard plots of the binding data are linear with a KD of 1.5 nM, a Bmax of 12.4 fmol/mg...
Administration of the indolealkylamine hallucinogen d-lysergic acid diethylamide (LSD), the phenethylamine hallucinogen 2,5-dimethoxy-4-methylamphetamine (DOM) and the putative 5-hydroxytryptamine (5-HT) agonist quipazine all produced a dose-dependent decrease in fixed ratio (FR-40) response rates and a concomitant increase in the number of 10-second pause intervals. Although naloxone (4.0...
cis- and trans-2-(2,4,5-trimethoxyphenyl)cyclobutylamine and trans-2-(2,5-dimethoxy-4-methylphenyl)cyclobutylamine were synthesized as conformationally restricted analogues of hallucinogenic phenylisopropylamines. In rats trained to discriminate saline from LSD (0.08 mg/kg, ip) in a two-lever drug discrimination paradigm, no generalization of the LSD stimulus to the cis trimethoxy compound...
The effects on a fixed ratio-40 (FR-40) operant behavior of intracerebroventricular (ICV) administration of the hallucinogens lysergic acid diethylamide (LSD), 2,5-dimethoxy-4-methylamphetamine (DOM), mescaline or the non-hallucinogenic LSD-analogue lisuride were compared with intraperitoneal (IP) administration. Infusion of LSD (8.5 to 34 micrograms) into the left lateral ventricle produced a...
AbstractThe ontogeny of the behavioral effects of lysergic acid diethylamide (LSD) was examined in cats between the ages of 4 and 112 days postpartum. The kittens showed little LSD‐induced behavioral change prior to 14 days of age. By the age of 21 days, however, the kittens exhibited many of the behavioral signs characteristic of LSD‐induced behaviors in adult cats. These behaviors include...
In Reply.— Dr Hoffman's suggestion that one may find many of the visual disturbances that were described in my article1 in non-LSD—using persons is well taken. The diagnosis of the LSD flashback syndrome, like that of epilepsy, is primarily made by carefully obtaining a history. But before drawing such a conclusion, the clinician has the responsibility of excluding the possibility of...
To the Editor.— I read with interest Abraham's article on "Visual Phenomenology of the LSD Flashback."1The description of visual flashbacks and the apparent reduction in symptoms with the administration of a benzodiazepine called to mind the case of a woman I treated whose major difference from the patients in Abraham's group was the absence of a history of LSD ingestion. This patient had...
Both acute and chronic effects of lysergic acid diethylamide (LSD) and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) on the dorsal root potential (DRP), evoked by stimulation of the nucleus raphe magnus of the cat, were examined. Single injections of LSD potentiated while those of 5-MeODMT inhibited the raphe-evoked DRP. The electrophysiologic response produced by each drug correlates well in...
Specific binding of [3H]lysergic acid diethylamide (LSD) to human platelet membranes, as defined by 300 nM spiperone, was saturable over the concentration range of 0.25-2.5 nM [3H]LSD. At 0.5 nM [3H]LSD the half-time for association at 37 degrees C was 56 min, half-time for dissociation was 173 min, and the kinetically derived affinity was 0.24 nM. In 19 control subjects equilibrium binding...