Oct 16, 2022
Organoids in a Rat Brain
Last Week in Medicine
Organoids are miniature forms of organs that originate from stem cells or a tissue, have the ability to self-renew and differentiate. These organs are produced in vitro and have been produced for many organs over the years. Thanks to organoids, we can observe how an organ develops from a single stem cell and how diseases occur during this developmental period.
I said that we can produce these tiny organs in vitro, that is, in a laboratory environment. In other words, these organoids do not have connections on humans, which are much more complex than a single organ. Therefore, they cannot become a developed organ, and their name remains organoid. Speaking of brain organoids, these organoids do not receive the external stimuli that are essential for their development. They are unable to develop new vessels and therefore cannot live for a long time.
In order to overcome such problems, a new study has been conducted. In this study, published in Nature, Revah et al. produced cortical organoids derived from human stem cells and transplanted them into the neonatal rat cortex.
Previous studies have shown that organoids transplanted into the rodent’s cortex are alive and able to form new connections, similar to a real brain. Because these studies were performed in adult rodent animals, the researchers speculated that this may have restricted the integration of organoids. Therefore, they used newborn rats. They observed that the organoids they transplanted to the somatosensory cortex received stimuli from rat whiskers and other sensory organs.
To demonstrate how their work could be used in developmental brain diseases, they developed a brain organoid from stem cells from three people with the genetic disorder Timothy Syndrome. When they transplanted the diseased organoids back into the rat cortex, they found that they didn’t work like other neurons and didn’t grow as much. In this way, they were able to show what is different in a brain with Timothy Syndrome from a healthy brain, with a rat brain.
Thanks to this discovery, we can better understand the developmental period of the brain. We can learn how the diseases seen in this period occur in the first place by creating new living organisms with the disease. Undoubtedly, drug discoveries will occur as well. These good developments also raise ethical problems. The level of consciousness of organoids is not yet known. It’s an enigma that it can evolve enough to give rise to human behavior. Also, considering the health of the rat, transplanted organoids can cause problems such as seizures or memory loss.
