Based on animal data, NMDA receptor hypofunction has been suggested as a model for positive symptoms in schizophrenia. NMDA receptor hypofunction affects several corticolimbic brain regions, of which the posterior cingulate seems to be the most sensitive. However, empirical support for a crucial role of posterior cingulate NMDA hypofunction in the pathophysiology of positive symptoms is still...
Since different meditations may activate different regions in brain, we can use functional magnetic resonance imaging (fMRI) to investigate it. Chinese original quiet sitting is mainly one kind of traditional Chinese meditation. It contains two different parts: a short period of keeping phrase and intake spiritual energy, and a long period of relaxation with no further action. In this paper,...
It has long been known that acute marijuana administration impairs working memory (e.g., the discrimination of stimuli separated by a delay). The determination of which of the individual components of memory are altered by marijuana is an unresolved problem. Previous human studies did not use test protocols that allowed for the determination of delay-independent (initial discrimination) from...
National drugs information strategies convey the message that use of Ecstasy is associated with an increase in both the incidence and severity of major depressive disorder. However, very little primary research supports this. Unlike apparent deficits in higher cognitive functions, most published studies have found no difference in self-reported depressive symptomatology between Ecstasy users...
The degree of alkylation of the side chain nitrogen in tryptamines is one important factor that affects psychoactivity. The method of Speeter and Anthony is considered to be one of the most important synthetic preparative methods. The final step in this reaction is based on the reduction of a (substituted) indole-3-yl-glyoxalylamide to the desired tryptamine with metal hydride. Twelve...
This is the first neuropsychological study using the S-enantiomer of the noncompetitive N-methyl-D-aspartate antagonist ketamine. In 2 randomized placebo-controlled trials we studied effects of two different doses of (S)-ketamine (low dose/high dose) on neuropsychological functions and psychopathology in 12 healthy male volunteers. Impairment was measured via standardized neuropsychological...
The present article reports the accumulation of N,N-dimethyltryptamine and its metabolic precursors (tryptophan, tryptamine) in different organs of micropropagated Mimosa tenuiflora trees (leaves, flowers and bark) subjected to seasonal variations (January and June), as well as in in vitro cultures (plantlets and calluses) of this plant species. The accumulation of all the tested compounds...
For several years, I have been interested in the Brazilian churches that use a particular mind-altering brew as a sacrament. This brew is referred to as "ayahuasca,""yage,""hoasca," etc., depending on the part of the country in which one encounters it. I am often invited to participate in evening ceremonies by the church elders, and one visit was especially memorable.
AbstractGeometry optimization for each member of a series of 15 substituted phenethylamines with reported psychotomimetic activity was performed using MM2 and MOPAC93 (AM1) methods. This was followed by calculation of previously developed, numerically unitary structure indices, viz., the molecular transform indices FTm, FTe, and FTc, indicating general, electronic, and charge properties...