1. The molecular nature and functions of the I(2) subtype of imidazoline binding sites are unknown but evidence suggests an association with monoamine oxidase (MAO). Rats can distinguish the selective imidazoline I(2)-site ligand 2-BFI from vehicle in drug discrimination, indicating functional consequences of occupation of these sites. We have used drug discrimination to investigate the nature...
The iboga alkaloid ibogaine and the novel iboga alkaloid congener 18-methoxycoronaridine are putative anti-addictive agents. Using patch-clamp methodology, the actions of ibogaine and 18-methoxycoronaridine at various neurotransmitter receptor ion-channel subtypes were determined. Both ibogaine and 18-methoxycoronaridine were antagonists at alpha 3 beta 4 nicotinic receptors and both agents...
Methylenedioxymethamphetamine (MDMA, “ecstasy”), widely used as a recreational drug, can produce hyponatraemia. The possibility that this could result from stimulation of vasopressin by MDMA or one of its metabolites has been investigated in vitro . Release of both oxytocin and vasopressin from isolated hypothalami obtained from male Wistar rats was determined under basal conditions and...
The root bark of Tabernanthe iboga contains ibogaine as its predominant alkaloid and has been an important source of it. Ibogaine is used experimentally to interrupt drug addiction and allow therapeutic intervention, but is currently unaffordable to doctors in less economically developed countries. To meet this need, an extraction of alkaloids from T. iboga root bark was optimized and...
We show that human consciousness can be modeled as a classical (not quantum) probabilistic computer. A quantum computer representation does not appear to be indicated because no known feature of consciousness depends on Planck's constant h, the telltale sign of quantum phenomena. It is argued that the facets of consciousness are describable by an object-oriented design with dynamically defined...
Even during well-calibrated cognitive tasks, successive brain responses to repeated identical stimulations are highly variable. The source of this variability is believed to reside mainly in fluctuations of the subject's cognitive "context" defined by his/her attentive state, spontaneous thought process, strategy to carry out the task, and so on... As these factors are hard to manipulate...
An increase of intoxications in persons using alkaloid-containing ornamental plants (mainly angel's trumpet) for their hallucinogenic effects and easy and cheap availability is registered. It is mainly adolescents who are experimenting with these plants. In addition to severe vegetative anticholinergic symptoms, the clinical picture is often dominated by a toxic psychosis with hallucinations,...
Current psychobiological models of drug addiction are focused on the capability of drugs to cause a pathological exploitation of the neural rewarding system. This approach has emphasized the role of hedonistic factors in the etiology of drug addiction. Comparing primitive and modern settings of intoxication, such as shamanic rituals and rave parties, it is possible to confute this assumption....
The pharmacology of the acute hyperthermia that follows 3,4‐methylenedioxymethamphetamine (MDMA, ‘ecstasy’) administration to rats has been investigated. MDMA (12.5 mg kg −1 i.p.) produced acute hyperthermia (measured rectally). The tail skin temperature did not increase, suggesting that MDMA may impair heat dissipation. Pretreatment with the 5‐HT 1/2 antagonist methysergide (10 mg kg −1 ), the...
Résumé Pratiquement inconnus dans les pays occidentaux il y a encore quelques décennies, l'ayahuasca et ses rituels y font aujourd?hui une entrée remarquable. Nous présentons une synthèse multi et interdisciplinaire de cette singulière préparation psychotrope, dont deux des alcaloïdes principaux sont na~turellement présents dans le corps humain. Les aspects pharmacochimiques (compositions,...