24 Sep
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Background of the Technology/Premise of the technology
Understanding how human brain functions has always been difficult. Humans have experimented on rat brains to investigate various human neurological disorders.
What are Brain Organoids?
Scientists are building 3D cultures of brain tissue in the lab, also called brain organoid. These “mini brains” (with a size of upto 4 mm) are built using human stem cells and capture many structural and functional features of a developing human brain. Researchers are now using them to study human brain development and test drugs to see how they respond.
Limitations of Organoids:
Human brains also require various sensor inputs (touch, smell, vision, etc.) to develop into complex organs it is, and the brain organoids developed in the lab aren’t sophisticated enough. The organoids currently also don’t have blood circulation, which limits how they can grow.
Transplanting Human Brain Organoids into rat brains:
- These brain organoids formed connections with the rat brain, which in turn provided circulating blood. Experiments found that human brain organoids were functionally active here.
- Scientists have touted such a system as a way to study brain disease in a human context.
Limitations: Even here, effects of drugs in this model will also have to be interpreted through structural behavioral tests in rats, which could be insufficiently representative.
What is the new Bio-Computer?
- John Hopkin University researcher’s scheme will combine brain organoid with modern computing methods to create bio-computers. They have announced plans to couple organoids with machine learning by growing the organoids inside flexible structures affixed with multiple electrodes (similar to the ones used to take EEG reading from brains)
- These structures will be able to record the firing patterns of the neurons and also deliver electrical stimuli, to mimic sensory stimuli. The response pattern of the neurons and their effect on human behaviour or biology will then be analyzed by machine-learning techniques.
- Scientists have already been successful in growing human neurons on top of a microelectrode array that could both record and stimulate these neurons. Using negative and positive electric feedback from the sensors, they were able to train the neurons to generate a pattern of electrical activity that would be generated if the neurons were playing table tennis.
Advantages/Opportunities of biocomputers:
- While human brains may be slower than computer at arithmetic, it is still faster than computers at processing complex information.
- Comparing data on brain structure connections and signaling between ‘healthy’ and ‘patient-derived’ organoid can reveal the biological basis of human cognition, learning and memory.
- They can also help decode the pathology of and drug development for devastating neurodevelopmental and degenerative disease such as Parkinson’s disease and microcephaly.
Bio-Computers are still not ready for commercial use.
Key steps required are:
- Scaling up the brain organoid is the key to improving computing capacity.
- Development of microfluidic systems to transport oxygen and nutrients and remove waste system.
- Scientists will also need to develop and use advanced analytical techniques (with the help of machines) to correlate the structural and functional changes in the brain organoids to the various output variables.
- Ethics team – to parallelly identify, discuss, and analyze ethical issues as they arise in the course of this work.