Replacing animals with nerves on a chip
A team of scientists have developed a way of guiding nerve cells to set up complicated networks that mimic the ones found in the brain. The work provides a new tool to researchers studying neurological diseases like Alzheimer's and could reduce the number of animals needed in such research.
Nerve cells in the brain carry signals in only one direction down long bodies called axons. These connect different parts of the brain. Current techniques using cells in petri dishes do not allow scientists to set up networks and lack the complexity of animal models. This severely limits the research possible. Using animals is also not perfect as it makes studying what happens inside the nerve cells very difficult. The new technique bridges the gap between the two systems using a brilliantly simple method.
The new system involves cell culture chambers connected by one-way channels. These force axons to grow in the direction the scientists need to connect one cell to the next, forming a network. It is a bit like growing an electrical circuit.
To test their model the scientists put cortical neurons (from the outer part of the brain) and striatal neurons (from the inner brain) into the two chambers. The neurons grew and formed a connection allowing an impulse to travel from the cortical neuron to the striatal one, mimicking their relationship in the brain.
The new technique will allow scientists to study how the neurons communicate and how diseases can disrupt the ability of the neurons to transmit signals.