Imperial College London scientists have developed an automated platform that can guide tiny measuring devices called micropipettes to specific neurons in the brains of live mice and record electrical currents. According to research published in Neuron today, this robot and computer program makes whole-cell recording (WCR), the notoriously difficult-to-perform gold-standard technique for studying the behavior of neurons under different brain states, much more accessible.
"To understand the brain as a whole organ, we need to know how neurons work and communicate with one another. Neurons in themselves are complex structures that use electrical and molecular signals to send information to neighbouring neurons, and the brain as a whole structure. Neurons also act differently depending on whether they are healthy or not fully functioning due to certain brain disorders. The WCR technique is a way to eavesdrop on these cells and how they communicate with their neighbours” senior author Professor Simon Schultz explained.
"However, structures that cannot be seen with the naked human eye require very precise and accurate ways to measure them. We have managed to do so successfully so far, but now we have taught robots to 'see' the neuron and perform the procedure even better. This means WCR can now potentially be performed on a much larger scale, which could speed up our learning about the brain and its disorders."
The conventional method for carrying out WCR involves scientists tagging a specific neuron with fluorescent protein or dye. In the new methodology this is achieved by guiding a robotic arm to the neuron, which is done by sending electrical pulses into the brain via a pipette filled with electrically conductive fluid. The pulses diffuse into the brain until the micropipette nears a neuron, which creates a block in electrical signal that tells the human or robot operator when to stop moving the micropipette.
At this point the micropipette clamps onto the outside of the cell, penetrating the membrane using a pulse of suction pressure. It then conducts any electrical signals from the neuron up through the micropipette, and into a computer via the conductive fluid.
The team says their technique is faster and more accurate than the conventional approach, and they intend to commercialize the program “so that research all over the world can benefit.”