Mini-brains the key to less animal testing? - by Floor Ruiter
(Video: A little 3D ball of central nervous system tissue (small brain) - Brown University)
A recent study by Brown University managed to produce small in vitro (cell culture) brains for possible Parkinson disease treatment studies and adult neural stem cells develop studies. Current brain studies are frequently done in animal studies. This miniature brain model could reduce the amount of animal studies.
To have an accurate in vitro model its important to similar properties to the natural rodent brain. The brain develop in this study showed many of these specific characteristics:
Diverse cell types: Brain is build of different types of cells. The cultured brain contained a variety of essential neural support cells (glia). inhibitory neurons and excitatory neurons.
Electrically active: Neurons communicate by electrical signals. The neurons in the culture showed fire and spikes and form synaptic connections to a complex network.
3D structure: Normal cell culture is in a 2D structure, while this tissue structure has a more realistic geometry, resulting in better cell connect and communication.
Natural cell density: Brain is a compact structure with a dense amount of cells per cubic millimeter. The mini-brain have a density of a few hundred thousand cells per cubic millimeter and is similar to the natural rodent brain density.
Physcial structure: The mini-brains show the same squishiness (mechanical strength) as a natural brain. This is due to the extracellular matrix formed by the mini-brain cell own protein expression.
The miniature brain are made by isolation and concentration cells combination for a small sample of living tissue from a rodent. This sample is seeded onto an agarose spherical model. Brain tissue begins to form within a day of seeding and a complex 3D neural network was observed within two to three weeks and kept alive for at least a month. The mini-brains are third of a millimeter in diameter and one single rodent tissue sample can produce thousands of these miniature brains. The production cost is validated to 25 cents per mini-brain, showing a big potential for big scale research applications.
