April 10, 2025

Chloe Harizate

11th Grade

Brooklyn Technical High School

One of the hardest organs to research is the brain– much is left unknown about it and its related conditions, its development, and its inner workings, which controls all life functions. The brain is a difficult organ to observe while “in action”. However, recently, scientific advancements have been bringing us closer to unlocking such knowledge, promising a potential to help us understand the pathology and pathogenesis of fatal diseases as well as shedding light on the overall complexity of the brain. 

As of now, 3D brain organoids are some of the closest technology that exists to observing the brain in an in vivo (living body) state, despite them not being part of a person or living body themselves. Brain organoids allow for the observation of a relatively accurate representation of the structure of human cerebral tissue, as well as neural brain development from a fetal stage– especially when compared to the other available alternatives such as: model organism brains, which although are “models” still cannot fully represent the human brain as they come from animals such as mice, rats, zebrafish, and other animals; post mortem brains, which pose ethical concerns and has limited uses since the tissue is dead; 2D brain structures which cannot display the workings of the human brain with as much detail in comparison to the 3D brain organoids; etc.

What is a 3D brain organoid? Brain organoids are rudimentary assemblies of brain tissue and neurons that, depending on how the organoid is developed, simplistically model the human brain in a specific part or as a generalized whole. In neuroscience labs, brain organoids are formed using a variety of liquid mediums and aggregated pluripotent stem cells. Matrigel is one of the important liquid mediums– it serves as the surface/ scaffolding on which the stem cells attach themselves, providing a proper surface and suitable environment for cells to grow, differentiate, and develop into a variety of brain cells and tissues. The Matrigel is essentially a gel-like protein substance derived from specific mice tumors. Pluripotent stem cells are stem cells with the ability to differentiate into any type of body cell. In making the 3D brain organoids, pluripotent stem cells are obtained by either harvesting human stem cells from an early embryo that has not yet undergone differentiation or by obtaining and manipulating adult cells in order to reestablish pluripotency.

Prior to the invention of the brain organoid,  organ technologies pertaining to lab grown organs already existed. In fact, the idea of lab-grown organoids has been around since the 20th century. However, the first successful lab-grown organoid occurred a bit more recently. In 2009, a laboratory in the Netherlands successfully grew organoids of the intestines following a scientific breakthrough in 1998, where it was found that stem cells could be isolated from mice, as well as human blastocysts (early embryos). Since then, the field of organoid cultivation has expanded, especially in the area of gastrointestinal sciences. Even more recently, a new area of organoid research– cerebral organoids– has been initiated. In 2013, an Austrian lab known as Vienna BioCenter grew the first brain organoids, publishing a paper describing the procedure for preparing brain organoids using human pluripotent stem cells. Around the same time, researchers in Kyoto, Japan, also pioneered this field also successfully creating some of the first samples of cerebral organoid tissues. Since then, other labs have started to look into the brain organoid technology and have been using it to learn about the brain and how diseases, like the Zika virus, affect the nervous system.

With the continued expansion of cerebral organoids and cerebral organoid technology, ethical concerns have been raised. Brain organoids are not completely organized the way a fully functioning human brain is. Still, this sparked controversy. In 2022, a lab in Australia claimed to have created a brain organoid labeled a “thinking system”. More specifically, the lab apparently connected the brain organoid they created to a video game using electrodes and recorded electrical energy given off by the organoid. In observing such, the lab claimed that the organoid learned to play the game within a short amount of time. Experiments such as these, and even just the idea of similar, elicit concern in some regarding the organoids’ potential for consciousness as well as the aspects of safety and morality that pertain to such. Still, some experts in the neuroscience community affirm that the organoids cannot become conscious entities, while others debate the extent to which that is true, especially as the use and development of brain organoids advance. In addition, there is also skepticism in regards to the ethicality of the sourcing of cells used to create the brain organoids. Granted, as this considerably new science evolves, unforeseeable issues such as those currently being postulated may arise. The skepticisms have validity as working with the brain comes with possible problems that can escalate if the ethical and safety aspects are not being considered as the technology is being used and further progressed.