N,N-dimethyltryptamine and the pineal gland: Separating fact from myth
The pineal gland has a romantic history, from pharaonic Egypt, where it was equated with the eye of Horus, through various religious traditions, where it was considered the seat of the soul, the third eye, etc. Recent incarnations of these notions have suggested that N,N-dimethyltryptamine is secreted by the pineal gland at birth, during dreaming, and at near death to produce out of body experiences. Scientific evidence, however, is not consistent with these ideas. The adult pineal gland weighs less than 0.2 g, and its principal function is to produce about 30 µg per day of melatonin, a hormone that regulates circadian rhythm through very high affinity interactions with melatonin receptors. It is clear that very minute concentrations of N,N-dimethyltryptamine have been detected in the brain, but they are not sufficient to produce psychoactive effects. Alternative explanations are presented to explain how stress and near death can produce altered states of consciousness without invoking the intermediacy of N,N-dimethyltryptamine.
Based on the studies reviewed above, a number of conclusions seem to merit consideration.
1. DMT is not produced in concentrations significant to activate CNS 5-HT 2A receptors, and is rapidly broken down by MAO if it is produced.
2. There is no evidence to suggest that DMT can accumu- late within the brain or within neurons at physiologically relevant concentrations; such inferences are either not supported by direct experimental evidence or are based on flawed experiments.
3. Endorphins, especially DYN, are released during stress, and DYN has very high affinity for the KOR, which can mediate hallucinations and out of body experiences. Other endorphins can mediate euphoria and analgesia through activation of mu or delta opioid receptors.
4. Asphyxiation or cardiac arrest paradoxically lead to brain activation and result in marked increases of brain neuro- transmitters such as dopamine, norepinephrine, and 5-HT, the latter of which can stimulate 5-HT 2A receptors.
5. Asphyxia induces excessive release of the excitatory amino acid, glutamate. Drugs such as ketamine, which also raise cortical glutamate, can produce out of body experiences.
6. Although the romantic notion that DMT is released from the pineal gland to produce altered states of conscious- ness at various times of stress is appealing to some, more well-studied systems provide more sound explanations for out of body experiences.
Case closed. En nu wil ik hier niemand meer over horen.