Scientists observe neural activity in lab-grown mini-BRAINS

Scientists in Japan have created mini-brains with functional neural networks.

These so-called mini brains, known more formally as cerebral organoids, may not be conscious, but their use in the lab could provide key insight to the processes by which information is encoded, scientists say.

The organoids are essentially a simplified version of the human brain which have been grown artificially using 3D tissue cultures.

They lack more supporting structures such as blood vessels and the surrounding tissues, and cannot ‘think.’

But, they’re still capable of some basic neural activity, the researchers say.

The team led by scientists at Kyoto University published their findings this week in the journal Stem Cell Reports.

‘Because they can mimic cerebral development, cerebral organoids can be used as a substitute for the human brain to study complex developmental and neurological disorders,’ says corresponding author Jun Takahashi, a professor at Kyoto University.

The team started with a ball of what are known as pluripotent stem cells, which can develop into various body tissues.

These cells were placed in a dish containing a culture medium that mimicked the environment necessary for cerebral development.

With the organoids grown, the team was then able to observe activity in network and connections between the individual neurons.

‘In our study, we created a new functional analysis tool to assess the comprehensive dynamic change of network activity in a detected field, which reflected the activities of over 1,000 cells,’ says first and co-corresponding author Hideya Sakaguchi, a postdoctoral fellow at Kyoto University.

‘The exciting thing about this study is that we were able to detect dynamic changes in the calcium ion activity and visualize comprehensive cell activities.’

According to the researcher, the technique could allow for a broad assessment of neural activity in human cells.

This could shed light on the processes behind memory and even the mechanisms of psychiatric disease.

But, it’s not without ethical concerns.

‘Because cerebral organoids mimic the developmental process, a concern is that they also have mental activities such as consciousness in the future,’ Sakaguchi says.

‘Some people have referenced the famous ‘brains in a vat’ thought experiment proposed by Hilary Putnam, that brains placed in a vat of life-sustaining liquid with connection to a computer may have the same consciousness as human beings.’

The researchers say, however, that an organoid with consciousness is an unlikely scenario given the environment in which they develop.