April 29, 2019 at 23:33Restoring circulation in the brain a few hours after death
It was previously believed that after a cardiac arrest or cessation of brain activity for other reasons, without oxygen and electrical activity, brain cells begin to die in a few minutes, and this process is irreversible. In this regard, doctors announced that the patient was brain-dead, which was the legal basis for recognizing death.
A study by scientists at Yale University in New Haven - Zvonimir Vrselja, Stefano G. Daniele et al - showed that this is not the case.
Experts have previously questioned the previous approach, because:
However, to date, alternative hypotheses have not been experimentally verified.
In a study published in Nature on April 17, 32 pig brains were involved, each of which was dead for 4 hours at the time of the test.
Scientists have developed a Brainex device that delivers blood substrate to the blood vessels of the brain extracted from the body: nutrients, contrast agents on ultrasound - and another to prevent the electrical activity of neurons (in order to protect cells from damage, and also for ethical reasons - in order to not to encounter the possible effects of brain activity outside the body, even hypothetically).
These brains retained metabolic activity (sugar uptake, carbon dioxide secretion) and immune responses, cytoarchitecture, cell death was weakened in them compared to the control group, where no restoration was taken. They also maintained electrical conductivity during stimulation from the outside.
A coordinated electrical activity, which, according to scientists, could talk about the course of conscious processes, was not noted.
Thus, the brain is able to persist much longer than previously thought. And this allows you to look at the issue of resuscitation and the onset of death from a new angle.
“For most of human history, death has been very simple,” says Christoph Koch, president and chief fellow at the Brain Institute. Allen in Seattle, Washington. “Now we must call into question WHAT is irreversible.”
Source
Ethics Discussion
A study by scientists at Yale University in New Haven - Zvonimir Vrselja, Stefano G. Daniele et al - showed that this is not the case.
Experts have previously questioned the previous approach, because:
- studies on cats and monkeys have shown that brain activity can be fully restored even several hours after the complete cessation of oxygen supply: science.sciencemag.org/content/168/3929/375 , www.sciencedirect.com/science/article/pii/0006899374904788 ;
- the experience of people who have experienced stroke and acute hypothermia showed that when blood circulation is restored, the brain returns to functioning in a life-adaptive format: emj.bmj.com/content/24/7/511.short , www.nejm.org/doi /full/10.1056/NEJMoa1713973;
- cells extracted from the brain and placed in a "cup" survived in the laboratory for several weeks: www.fasebj.org/doi/10.1096/fj.01-0504com .
However, to date, alternative hypotheses have not been experimentally verified.
In a study published in Nature on April 17, 32 pig brains were involved, each of which was dead for 4 hours at the time of the test.
Scientists have developed a Brainex device that delivers blood substrate to the blood vessels of the brain extracted from the body: nutrients, contrast agents on ultrasound - and another to prevent the electrical activity of neurons (in order to protect cells from damage, and also for ethical reasons - in order to not to encounter the possible effects of brain activity outside the body, even hypothetically).
These brains retained metabolic activity (sugar uptake, carbon dioxide secretion) and immune responses, cytoarchitecture, cell death was weakened in them compared to the control group, where no restoration was taken. They also maintained electrical conductivity during stimulation from the outside.
A coordinated electrical activity, which, according to scientists, could talk about the course of conscious processes, was not noted.
Thus, the brain is able to persist much longer than previously thought. And this allows you to look at the issue of resuscitation and the onset of death from a new angle.
“For most of human history, death has been very simple,” says Christoph Koch, president and chief fellow at the Brain Institute. Allen in Seattle, Washington. “Now we must call into question WHAT is irreversible.”
Source
Ethics Discussion