The scientists have developed a special nanoelectrode chip to record the activity of hundreds of synapses at the same time, which gives a unique insight into the brain function.
FREMONT, CA: The brain neurons make use of electric signals for interacting. The scientists have been recording them with electrodes since the 1970s. A group of scientists from the Harvard John A, Paulson School of Engineering and Applied Sciences, has utilized a unique kind of nanoelectrodes that managed to record the electric signals of the neuron networks of the brain for the first time in history.
The electronic chip developed by the researchers is able to perform high-sensitivity intracellular recording from the huge number of connected neurons simultaneously. This innovation has enabled them to map the synaptic connectivity at a phenomenal level, identifying many synaptic connections.
Deploying sensitivity and parallelism in unison can benefit fundamental and applied neurobiology alike, even for processes such as the construction of functional connectome and electrophysiological screening with high-throughput.
This prolonged sought-after parallelization of intracellular recording has enabled the mapping of the biological synaptic network, which can generate a new machine intelligence strategy for building next-generation neuromorphic processors and artificial neural networks.
The scientists used similar fabrication technology as computer microprocessors to create the electronic chip. The chip includes a dense array of nanometer scale electrodes standing vertically on its surface. These electrodes are operated by an underlying integrated circuit. Each nanoelectrode is coated with platinum powder giving it a rough surface, which enhances its ability to pass the signals.
The neurons are cultured directly on the chip. A current is sent to each coupled neuron by the integrated circuit via the nanoelectrode to open small holes in its membrane, which creates intracellular access. At the same time, the same integrated circuit amplifies the voltage signals from the neuron, which is picked up by the nanoelectrode through the holes.
In experiments, more than 1,200 rat neurons were recorded by the array. The 20 minutes of recording surprised the researchers and further enabled them to map more than 300 synaptic connections.
The high-throughput, high-precision chip was also used to measure the drug effects on the synaptic connection across the rat neuronal network. The scientists are now aiming at developing a wafer-scale system for drug screening for neurological disorders like schizophrenia, autism, addiction, Parkinson's disease, and Alzheimer's disease.