Injecting human genes into the monkey’s brain, German and Japanese scientists announced that the brain of the treated monkey fetus nearly doubled in size. The experiment was not allowed to pass the fetal stage due to ethical concerns and unpredictable results.
Scientists added human genes to the monkey brain by signing an experiment reminiscent of the ‘Hell of the Apes’ movie. The results of the study conducted by the Max Planck Institute of Molecular Cell Biology and Genetics in Germany and the Central Institute of Experimental Animals in Japan were published in the journal Science.
As part of the study, German and Japanese researchers injected a gene called ARHGAP1, which directs stem cells in the human brain, into the brains of marmoset fetuses, known as a primate species. In the findings shared in June, it was stated that the neocortex part of the primate brains, which is responsible for cognition and language, developed and grew after the procedure.
Monkey brains nearly doubled in size:
According to the images published by the researchers, the modified monkey brains nearly doubled in size at about day 100 of pregnancy. Speaking about the results, Michael Heide, author of the study, said: “We really found that the neocortex of the ordinary marmoset brain is expanding and the brain surface folds.”
As a result of the investigations, scientists said that the neocortex is the newest evolutionary part of the brain. This part, which makes up about three-quarters of the mass of the human brain, is involved in the execution of higher functions peculiar to humans such as sensory perception, the formation of motor commands, conscious thinking and language.
Although the experiment resulted in monkey fetuses having larger, more developed and more human-like brains, scientists chose to remove monkey fetuses by cesarean section due to ethical concerns and “unpredictable results.”
Wieland Huttner, one of the study’s authors, said in a press release that it would be irresponsible and unethical to allow the experiment to pass the fetal stage and the apes carrying the human gene to be born.