look up the book called DMT The Spirit Molecule, by Dr. Rick Strassman... very interesting book....
DMT is basically the substance produced by your pineal gland in your brain, and its what makes you dream at night during heavy REM sleep. Its also in plants, reptiles, and other animals..... Dr strassman concludes he thinks it is the seat of the soul..... trips on DMT are very similar to out of body experinces, and near death experiences......