During the waking state, a late component of the auditory event-related potential, P300, is elicited when subjects detect a rare 'target' stimulus. It is usually not elicited when subjects either ignore or fail to detect the stimulus. The presence of P300 is therefore thought to reflect conscious processing of the stimulus. Since P300 has been shown to be an attention-dependent cognitive...
RationaleAyahuasca, a South American psychotropic plant tea, combines the psychedelic agent and 5-HT(2A/2C) agonist N, N-dimethyltryptamine (DMT) with beta-carboline alkaloids showing monoamine oxidase-inhibiting properties. Current human research with psychedelics and entactogens has explored the possibility that drugs displaying agonist activity at the 5-HT(2A/2C) sites temporally disrupt...
The hallucinogen d-lysergic acid diethylamide (d-LSD) evokes dramatic somatic and psychological effects. In order to analyze the neural activation induced by this unique psychoactive drug, we tested the hypothesis that expression of the immediate-early gene product c-Fos is induced in specific regions of the rat forebrain by a relatively low, behaviorally active, dose of d-LSD (0.16 mg/kg,...
This article presents data from two avenues of marijuana research. First, the author shows that daily marijuana smoking in healthy individuals produces dependence, as demonstrated by withdrawal symptoms such as increased irritability and depression and decreased food intake. In addition, two antidepressant medications were evaluated to assess their potential effectiveness in the treatment of...
Epiphenomenalism is shown to be absurd because the development of consciousness must be explainable through natural selection. A detailed neuromolecular basis of the neuromediator release is given and it is stressed on the possible key point where the quantum mind could act, namely presynaptic scaffold protein dynamics and detachment of the calcium sensor v-SNARE synaptotagmin-1. The...
Les qualia , considérés comme des propriétés intrinsèques de nos expériences, ne sont pas toujours bien accueillis par les matérialistes, qui préfèrent les considérer comme des propriétés intentionnelles présentées dans l’expérience. Je me demande si cette forme de réductionnisme s’applique aux qualia de la conscience corporelle. Selon la théorie matérialiste standard, l’objet intentionnel de...
There is substantial evidence that lisuride can produce effects linked to 5-HT(1A) receptor occupancy. Nevertheless, this action has generally been ignored in the mechanism of action of lisuride, in favor of an exclusive role for dopamine receptors in considering its antiparkinsonian effects, or an exclusive role of 5-HT(2A/2C) receptor activation in hallucinogenesis. These conclusions are...
Neuroscience LettersSeptember 27, 2002Werner J Schmidt, Andreas Mayerhofer, Anja Meyer et al.
Parkinson's disease is due to a dopamine deficiency caused by the degeneration of midbrain dopamine neurons. Current therapies are aimed to substitute dopamine or to directly stimulate postsynaptic dopamine receptors. However, not all patients profit from current therapies to the same extent, even serious side effects such as dyskinesias are complicating the therapy. Therefore, there is still a...
Neuroscience LettersSeptember 27, 2002Anja Meyer, Andreas Mayerhofer, Karl‐artur Kovar et al.
3,4-methylenedioxy-methylamphetamine (MDMA) ('Ecstasy') and its analogue 3,4-methylenedioxy-methylamphetamine (MDE) ('Eve') are well known illicit street drugs mainly abused by young people. In spite of the actual research going on, the classification of their abuse potential remains unclear. Since secondary reinforcers are the main factors responsible for craving and relapse, the aim of our...
Salvia divinorum, whose main active ingredient is the neoclerodane diterpene Salvinorin A, is a hallucinogenic plant in the mint family that has been used in traditional spiritual practices for its psychoactive properties by the Mazatecs of Oaxaca, Mexico. More recently, S. divinorum extracts and Salvinorin A have become more widely used in the U.S. as legal hallucinogens. We discovered that...