IN_FINITE. Living with Death.

Absolutely. When the wave sets in, processes begin that
are toxic for the nerve cells. The clock starts ticking. An
enormous stress begins for the cells. For example, the
nerve cells and their processes swell enormously, which
you can observe under a two-photon microscope.
What exactly happens when this wave is unleashed?
This wave is truly a colossal event. Neurotransmitters are
released en masse. There is actually no neurotransmitter
that is not released during this phase. The wave spreads
slowly throughout the brain. This releases a lot of electrochemical
energy, which is converted into heat. At
the front of the wave, there are a few action potentials,
which are impulses that can also occur under normal
conditions. Then there is utter silence. The simplest way
to describe the wave is as a short circuit in a battery. The
nerve cells lose their electrical charge with the wave.
That means there’s no energy left to generate any more
impulses. What I personally find important, however,
is that this spreading depolarization is not the wave of
death itself. That’s not the case. The wave induces toxic
processes, after which it takes a while for the nerve cells
as such no longer exists. In mechanistic terms, the occurrence
of a vegetative state is connected with the fact
that the cerebral cortex is considerably more susceptible
than the brain stem to the development of a spreading
depolarization.
When does the process become irreversible?
When the organelles of the depolarized nerve cells are
so badly damaged that they can no longer function adequately
even after energy is restored.
So that’s the point of no return.
Yes, but it is not simultaneous with the wave. The wave
begins and you still have two or three minutes. Only then
do the nerve cells begin to die. Energy is an apt image
for me here. Our brains are normally full of energy. Each
nerve cell is both a power plant that generates energy
from oxygen and glucose, and an energy consumer.
The energy produced in the power plants is stored and
used to generate signal impulses. Normally, a very large
amount of energy is stored, only a fraction of which
is used in the form of impulses, or what are known as
action potentials. But that’s still quite a bit. Although it
a few minutes. If blood flow to the brain is not restored,
all 86 billion of our neurons will eventually be completely
discharged and eventually so poisoned that they will die.
What does dying feel like? What do we know
about it? You speak of an enormous wave.
People also talk about a final great display of
fireworks …
The reports of patients who were resuscitated and
survived are the only things we can rely on. A patient lies
there, unconscious, and appears to be dead although
that is not yet the case. Their heart no longer beats but
their nerve cells are still alive. Around 15 percent of people
who are resuscitated have a conscious experience
during this period. There are various speculations about
what might be responsible for near-death experiences.
Such as?
A relatively interesting thought is that there may be a
surge of activity in the initial phase, a final flare-up, so to
speak, before the spontaneous electrical activity of the
brain comes to a halt. This surge of activity might have
something to do with near-death experiences. What is
migraine auras, however, also describe a type of tunnel
vision and/or bright lights. The source of the aura is a
wave, which is very similar to what occurs in a stroke or
in the process of dying.
Which phenomena are considered to be neardeath
experiences?
Notable features of near-death experiences include a
sense of simultaneity, a sense of being in multiple places
at essentially the same time, and the ability to be of different
ages at the same time. That would fit in well with
a coordinated short-term process in the brain by which
a great many nerve cells are – more or less simultaneously
– activated and call up our (stored) memories at
nearly the same time. A look back in time, when your life
seems to flash before your eyes. Other phenomena include
out-of-body experiences, although these can also
be triggered in other contexts, such as during epileptic
seizures or by magnetic stimulation of certain regions of
the brain.
To what extent are images like the white tunnel
influenced by cultural and religious ideas?
to die. If circulation and a supply of energy are restored
after the onset of the wave, the process is entirely reversible
up to a certain point in time and the nerve cells
can also recover. In the case of a stroke, the waves can
also spread far into healthy tissue with a normal blood
supply, where they can have important signalling functions
for the organism, so that their effects need not always
be negative. It’s all very complicated.
accounts for only 2 percent of the body’s weight, the
brain uses 20 percent of our caloric intake to produce
enough energy for its IT activities around the clock.
In other words, as long as the body is at rest and not
running a marathon, for example, the brain is the body’s
greatest consumer of calories. That being said, much
more energy is stored in the brain than is used at any
given moment. Similar to a battery, energy is stored in
also important is that different regions of the brain can
be in various stages of the process of dying. One region
might already show a spreading depolarization, whereas
another might not yet be affected. Another possibility
is that it is not actually the transitional phase from life
to death that gives rise to near-death experiences but
rather what happens afterwards if resuscitation is
successful. What is also conceivable is that near-death
Most studies on this topic tend to come from a Western
cultural context. But I recently read a report from
Sri Lanka, which has several religions in a relatively
small geographic area. The researchers found different
frequencies in the mention of near-death experiences,
with a somewhat higher rate from areas with Christian
influence. On the other hand, they reported such experiences
from all the religions studied. Atheists, too, can
Is there a point of no return?
Yes, but this point is hard to define. For example, not all
nerve cells die at the same time, because some are very
vulnerable and others less so. That is why there can also
be situations in which some nerve cells start dying but
others are still alive. If resuscitation efforts are successful,
the patient might lose some of their nerve cells
and retain others. This, of course, is a crucial factor for
the quality of life that can be achieved thereafter. One
special variant here would be a vegetative state in which
only the brain stem is capable of functioning. Respiration,
circulation and a sleep-wake cycle are possible, but
higher brain functions no longer work and the individual
each individual nerve cell by separating ions across the
cell membrane. It’s essentially the same thing that happens
in a flashlight battery. Turning the torch on and then
quickly off again would correspond to a nerve impulse.
Turning the torch briefly on and off uses only a tiny fraction
of the energy stored in its battery. You can repeat
that for a long period of time before the battery loses its
charge. In contrast to simple signal impulses, spreading
depolarization is an event in which the neurons, meaning
the “miniature batteries”, suffer a short circuit and
essentially lose all their charge at once. This short circuit
doesn’t take place everywhere at the same time, however,
but instead migrates slowly through the brain from
neuron to neuron, reaching ever more locations within
experiences arise while the brain is regenerating. In
the aftermath of a successful resuscitation, there are
patterns of electrical activity in the brain similar to those
observed in the context of hallucinations from other
causes. The question of near-death experiences constitutes
a broad field.
Many people report seeing a tunnel of white
light. Are there scientific explanations for this?
I find the white tunnel interesting because these types
of light-related phenomena also occur in migraine with
aura. A typical migraine aura consists of a jagged ringlike
image that usually begins in the middle of the field of
vision and slowly extends outwards. Some patients with
have them. There are also historical accounts of what we
would now call near-death experiences. They occur in
different contexts, religions and eras. All of this suggests
that the ability to have near-death experiences is a
fundamental feature of Homo sapiens.
How do people respond to these near-death
experiences?
The literature suggests that around 90 percent of neardeath
experiences are viewed in very positive terms.
Most people report a feeling of joy. Around 10 percent
are negative, however, and interpreted as hellish, for
example. Many people report meeting others who
predeceased them, an experience they often portray
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