It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Can neuroscience shed light on one of life's biggest mysteries - death? In a new study just published in PNAS, researchers observed a surge of brain activity just moments before death. This raises the fascinating possibility that they have identified the neural basis for near death experiences.
First, to put this research into context, death-related brain activity was examined in rats, not humans. For obvious reasons, it is easier to study the death process in animals rather than humans. In this study, nine rats were implanted with electrodes in various brain regions, anaesthetised then 'euthanized' (i.e., killed). The exact moment of death was identified as the last regular heartbeat (clinical death). Electroencephalogram (EEG) was recorded during normal waking phase, anaesthesia and after cardiac arrest (i.e., after death) from right and left frontal (RF/LF), parietal (RP/LP) and occipital (RO/LO) cortex. The raw EEG (i.e., ‘brain waves') for each area is shown in the Figure below.
On top (Panel A), the recording ranges from about 1hr before death to 30mins afterwards. At this coarse time scale you can basically see a sudden decrease in brain activity after cardiac arrest - everything seems to flatline at the moment of death. However, if we now zoom in on the moment just after death (Panels B and C below), we can see that the death process actually involves a sequence of structured stages, including a surge of high-frequency brain activity that is normally associated with wakefulness and conscious awareness.
In this study, the neuroscientists distinguish four distinct stages of brain death. Cardiac arrest stage 1 (CAS1) reflects the time (~4 seconds) between the last regular heartbeat and the loss of a oxygenated blood pulse (i.e. clinical death). The next stage (CAS2) lasts about 6 seconds, and ends with a burst in low-frequency brain waves (so-called 'delta blip'). The third death stage, CAS3, lasts approximately 20 seconds at which point there is no more evidence of meaningful brain activity at the final stage, CAS4.
These stages seem to reflect an organized series of distinct brain states, rather than a gradual fade out of brain activity. First, we see a sudden transition from the anaesthetised state with an increase in fast brain waves. It is as if the brain is suddenly shaken from the effects of anaesthesia at the moment of death. Next, brain activity settles into a period of slower brain waves during CAS2. Perhaps most surprisingly, recordings are then dominated in CAS3 by brain waves more commonly associated with normal wakefulness during life (so-called gamma activity). In further analyses, the researchers also show that this ‘afterlife' brain activity is also highly coordinated across brain areas and different wavelengths. These are the neural hallmarks of high-level cognitive activity. In sum, these data suggests that long after clinical death, the brain enters a brief state of heightened activity that is normally associated with wakeful consciousness.
Interestingly, the authors even suggest that the level of activity observed during the final active death stage (CAS3) not only resembles the waking state, but might even reflect a heightened state of conscious awareness similar to the "highly lucid and realer-than-real mental experiences reported by near-death survivors". This is a pretty bold claim that critically depends on their quantification of 'consciousness'. They argue that in the final stage of brain death there is actually more evidence for consciousness-related activity than during normal wakeful consciousness.
"From infancy onwards babies must come to grips with a world marked by recurrent time patterns, learning the length of time, or duration, associated with the various actions they experience every day," says Professor Sylvie Droit-Volet, at the Social and Cognitive Psychology Laboratory (Lapsco) at Blaise Pascal University, Clermont Ferrand, France. "They react, become agitated or cry, when something they expect does not occur on time: when the mobile over their bed stops turning earlier than usual, when their mother takes too long preparing a feed," she adds.
Very young children "live in time" before gaining an awareness of its passing. They are only able to estimate time correctly if they are made to pay attention to it, experiencing time in terms of how long it takes to do something. "For a three-year-old, time is multifaceted, specifically related to each action," Droit-Volet explains. At the age of five or six a child is able to transpose the duration it has learned to associate with a particular action (pressing a rubber ball) to another (pulling on a lever). "They begin to realise that a single time continuum exists separately from individual actions," she adds.
The awareness of time improves during childhood as children's attention and short-term memory capacities develop, a process dependent on the slow maturation of the prefrontal cortex. To gauge the time required for a task they must pay attention to it. But they must also memorise a stream of time-data without losing concentration.
Published in Science in 1961, Julius Axelrod found an N-methyltransferase enzyme capable of mediating biotransformation of tryptamine into D MT in a rabbit's lung. This finding initiated a still ongoing scientific interest in endogenous D MT production in humans and other mammals. From then on, two major complementary lines of evidence have been investigated: localization and further characterization of the N-methyltransferase enzyme, and analytical studies looking for endogenously produced D MT in body fluids and tissues.
In 2013 researchers first reported D MT in the pineal gland microdialysate of rodents. In the popular drug culture, this has been expanded to an assertion that it occurs in the human pineal gland, and is released at or shortly before death, but this conjecture has not yet been scientifically verified.
A study published in 2014 reported the biosynthesis of N,N-dimethyltryptamine (D MT) in the human melanoma cell line SK-Mel-147 including details on its metabolism by peroxidases.
In a 2014 paper a group first demonstrated the immunomodulatory potential of D MT and 5-MeO-D MT through the Sigma-1 receptor of human immune cells. This immunomodulatory activity may contribute to significant anti-inflammatory effects and tissue regeneration
We’re excited to announce the acceptance for publication of a paper documenting the presence of D MT in the pineal glands of live rodents. The paper will appear in the journal Biomedical Chromatography and describes experiments that took place in Dr. Jimo Borjigin’s laboratory at the University of Michigan, where samples were collected. These samples were analyzed in Dr. Steven Barker’s laboratory at Louisiana State University, using methods that funding from the Cottonwood Research Foundation helped develop.
The pineal gland has been an object of great interest regarding consciousness for thousands of years, and a pineal source of D MT would help support a role for this enigmatic gland in unusual states of consciousness. Research at the University of Wisconsin has recently demonstrated the presence of the D MT-synthesizing enzyme as well as activity of the gene responsible for the enzyme in pineal (and retina). Our new data now establish that the enzyme actively produces D MT in the pineal.
The next step is to determine the presence of D MT in cerebrospinal fluid (CSF), the fluid that bathes the brain and pineal. CSF is a possible route for pineal-synthesized D MT to effect changes in brain function. Successfully establishing D MT’s presence in this gland adds another link in the chain between the pineal and consciousness and opens new avenues for research.
originally posted by: sparky31
nope i,m sorry i don,t buy it,i did at one point think theres njust not convinced there is a soul that continues your journey,there is totally no evidnce of it.