In science-fiction films such as 'Frankenstein' and 'Re-Animator' the human body is reanimated, existing in a strange state between life and death.
Though it may sound fantastical, a 'third state' of existence actually exists in modern biology, according to a new study.
According to researchers, the third stage is where the cells of the dead organism continue to function even after its death.
Biologists say that surprisingly, after the death of an organism, its cells acquire new abilities, which they did not have during life.
If further experiments on cells from dead animals – including humans – show they can enter the third stage, they could 'redefine legal death'.
Researchers say that after an organism dies, cells acquire new abilities that they did not have in life. Different types of cells have different abilities to survive (file photo)
In science-fiction films such as 'Frankenstein' and 'Re-Animator' the human body is brought back to life, existing in a bizarre state between life and death.
New Study In The physiology is led by professors Peter Noble of the University of Washington in Seattle and Alex Pozitkov of the City of Hope National Medical Center in Duarte, California.
“Life and death are traditionally thought of as opposites,” he says in a new article for The Conversation.
'But the emergence of new multicellular life-forms from the cells of a dead organism introduces a 'third state' that goes beyond the traditional boundaries of life and death.
'Some cells, when provided with nutrients, oxygen, bioelectric or biochemical signals, have the ability to transform into multicellular organisms with new functions after death.'
The team reviewed recent studies that examined the remarkable ability of cells to continue to exist in new forms after the organism's death.
In 2021, researchers in the US found that skin cells from dead frogs were able to adapt to petri dishes in the laboratory, and spontaneously reorganise into multicellular organisms called 'xenobots'.
These organisms showed behaviours beyond their basic biological roles – using their cilia – tiny, hair-like structures – to move around in the surrounding environment.
In the 1980s classic film 'Re-Animator,' a medical student discovers a way to bring human tissue back to life
Pictured are computer-designed creatures that collect single cells inside a Pac-Man-shaped 'mouth' and release 'babies' (green)
Other scientists have also found that human lung cells can transform themselves into miniature multicellular organisms that can move around – called 'anthrobots'.
These anthrobots can not only travel around their surrounding environment, but can also repair themselves and the surrounding injured nerve cells.
The team says these are examples of new cell functions that do not exist in life, and 'represent changes in ways that are not predetermined.'
It is still unclear how some cells function in the third stage after an organism's death, but one possible Frankenstein-style explanation is a hidden system of 'electrical circuits' that regenerate cells.
The team say: 'One hypothesis is that special channels and pumps embedded in the outer membranes of cells function as complex electrical circuits.
Figure A shows a human patient forming a bridge across a scratched nerve over three days. Figure B shows the 'suture' in green at the end of the third day
This anthrobot is made from human lung cells, molded into a new shape that can crawl and repair damaged tissue
Xenobots can collect hundreds of single cells, compress them and combine them into 'babies' that emerge from their Pac-Man-shaped mouths
'These channels and pumps generate electrical signals that enable cells to communicate with each other and perform specific functions, such as growth and movement, thereby shaping the structure of the organism.'
Whether cells have this ability depends on a number of factors, including environmental conditions (such as temperature) and the energy source (whether they have fuel available and can metabolize it).
The research team further said, 'Metabolic activity plays a vital role in whether cells can survive and function.'
Factors such as age, health, sex and species type also 'shape the death scenario' – in other words, whether they can survive into the third stage.
Ultimately, this research points to 'unknown frontiers' that could bring animal cells to a third state – although whether this will one day be like 'Re-Animator' remains to be seen.
In the 1980s classic film, a medical student discovers how to reanimate human tissue — with violent results.
The study authors concluded, 'This research has the potential to transform regenerative medicine, redefine legal death, and provide insights into the physiological limits of life in parallel with investigations into embryogenesis.'