Brain cells, or neurons, communicate by exchanging biochemicals and electrical signals across a synapse – a tiny gap between neurons. Now Stanford University scientists have built their own synapses that can communicate with living neurons, using the same molecules as the human brain.
The manmade version uses two soft polymer electrodes separated by a trough holding a liquid electrolyte – a solution able to transmit electric charges. The trough mimics the gap between neurons in the brain.
Living cells are placed on top of an electrode. The cells release neurotransmitters, the chemicals that spark electrical signals between neurons.
The neurotransmitters react with the electrode to make ions, or electrically-charged chemical particles. The ions travel through the electrolyte in the trough to the other electrode, changing its electrical state. That change becomes permanent, mimicking the way learning takes place in the brain.
The synthetic synapse combines computing and memory in one action, while computers calculate first, then move the result into memory in a separate operation.
The researchers tested their creation using rat brain cells that release dopamine, a common neurotransmitter involved in thinking, planning, and feeling pleasure. They found the artificial synapse worked as smoothly as the real thing.
TRENDPOST: Having a working model of a natural synapse makes it easier to study how the brain works and learns and designs brain-machine links. The device also implies robots could some day think and learn as humans do.
The first computers were the size of your bedroom and could do little more than arithmetic. Eventually, synthetic synapses could be miniaturized through nano-engineering and replace damaged cells within the brain itself.
