We talked a bit in other threads about breathwork and the possible links to DMT release from the lungs... well one of the powerful techniques in Pranayama is called Kumbhaka which amounts to basically just holding the breath for a long time.

Of course there is more to it, one might have done a lot of other techniques prior to starting kumbhaka, and often it is held in conjunction with very long inhales and long ehales, but to get to the point here... if DMT has a neuroprotective effect then it would make sense that the body would want to release it when the brain is undergoing oxygen deprivation.

And this can also explain a lot of the NDE experiences in cardiac arrest, if so. Again, only speculating, but my personal experiences with pranayama make me think that there is something to it.

Abstract
Psychedelic agents have a long history of use by humans for their capacity to induce profound modifications in perception, emotion and cognitive processes. Despite increasing knowledge of the neural mechanisms involved in the acute effects of these drugs, the impact of sustained psychedelic use on the human brain remains largely unknown. Molecular pharmacology studies have shown that psychedelic 5-hydroxytryptamine (5HT)2A agonists stimulate neurotrophic and transcription factors associated with synaptic plasticity. These data suggest that psychedelics could potentially induce structural changes in brain tissue. Here we looked for differences in cortical thickness (CT) in regular users of psychedelics. We obtained magnetic resonance imaging (MRI) images of the brains of 22 regular users of ayahuasca (a preparation whose active principle is the psychedelic 5HT2A agonist N,N-dimethyltryptamine (DMT)) and 22 controls matched for age, sex, years of education, verbal IQ and fluid IQ. Ayahuasca users showed significant CT differences in midline structures of the brain, with thinning in the posterior cingulate cortex (PCC), a key node of the default mode network. CT values in the PCC were inversely correlated with the intensity and duration of prior use of ayahuasca and with scores on self-transcendence, a personality trait measuring religiousness, transpersonal feelings and spirituality. Although direct causation cannot be established, these data suggest that regular use of psychedelic drugs could potentially lead to structural changes in brain areas supporting attentional processes, self-referential thought, and internal mentation. These changes could underlie the previously reported personality changes in long-term users and highlight the involvement of the PCC in the effects of psychedelics.
Copyright

http://www.ncbi.nlm.nih.gov/pubmed/25637267

It seems that DMT May be the endogenous ligand for the sigma-1 receptor...which I could get into again, but will hold off for now...

I have been doing some breath work, but ultimately my heart rests with entheogens.

Another point I should make involves the fact that I don't actually use many of the compounds I research, even DMT and the true psychedelics are a very rare treat, but that's the beauty in these things, you don't need them often, there is lasting impact...

Neuroplasticity is an interesting point of research: