Researchers in Austria have managed to manipulate the growth of stem cells into the preliminary stages of the human brain.
For all of modern understanding of human anatomy, the brain is ironically still a relative unknown. In an effort to further our knowledge, a team led by Jürgen Knoblich managed to successfully culture pluripotent stem cells into small neural clusters called cerebral organoids. By growing the stem cells suspended in a nutrient wash while encapsulated in beads of a porous material known as matrigel, the team was able to more accurately replicate the conditions a newly forming brain would experience, and under which the cells developed into organoids of their own volition, without the need for micro-manipulation of the cells into the desired formation.
While remarkable, the tiny neural structures are not Frankenstein-esque, “brains in a jar”. Knoblich remarks, “They’re nowhere near an adult human brain and they don’t form anything that resembles a neuronal network.” In comparative terms of brain development inside a human, the cerebral organoids are only on par to a nine week old foetus, although the team were able to identify distinct yet rudimentary zones corresponding to areas such as the hippocampus, occipital lobe, and prefrontal cortex.
While model organisms such as mice are useful in conducting research into how brains work and grow, the differences in complexity between our brains and theirs means we would never gain a full understanding by studying them alone. From Arnold Kriegstein, who was not a part of the experiment, these cellular bundles are “the most complete to date in terms of features that directly resemble those in the developing human brain”. Work has already been carried out by the team in regards to how the new technique might prove useful to research, by using it on the induced pluripotent stem cells from a patient suffering from microcephaly, in which the brain is of markedly smaller size than average. As the cells divided, rather than following the forms of the organoids which went before it, they proliferated into a mass of neurons before abruptly ceasing.
This new technique could prove useful in researching complex brain growth and development in a controlled environment, as well as experimenting with mutations which are otherwise too problematic to study in vivo. As the technology advances, so too will the understanding of the human brain.