A breakthrough in animal brain interfaces could lead to exciting progress in the repair of brain damage in humans, writes Joseph Lawlor
Scientists from Tel Aviv University in Israel have managed to further reduce the ever-decreasing gap between science fiction and reality by developing a synthetic cerebellum chip that can receive sensory inputs from a rat’s brainstem and restore lost brain function. The brainstem is an area of the brain concerned with neural conduction, and unlike previous implants, such as cochlear and prosthetic limbs that conduct one-way communication between the brain, or vice versa, the ‘chip’ can record, analyse and return a signal to the brain. This work was presented by Matti Mintz in September at the Strategies for Engineered Negligible Senescence meeting in Cambridge.
To prove that this concept was a possibility, Mintz and his colleagues studied the cerebellum, which is primarily concerned with coordinating and timing movement. This area is well understood as it consists of a relativity simple neural network, making following the natural biological neural ‘map’ easier to copy and test. The team analysed the communications between the cerebellum and the brain stem in real time on a chip that was placed outside the skull and was wired into the brain stem to generate a synthetic version.
When testing the chip, a rat was anaesthetised and its cerebellum was disabled before the synthetic version was attached. The anaesthetisation of the rat caused the amount of neural communication to be reduced significantly and thus made it easier to follow and measure. The animal’s blinking motor reflex was then conditioned; upon the rat hearing a tone it would simultaneously receive a puff of air into its eye. The rat eventually learnt to ‘blink’ upon hearing the tone alone, only in expectation of the puff of air. Prior to the chip being connected the animal was unable to ‘blink’, however upon connection of the chip the animal displayed the ‘blink’ reflex upon hearing of the tone.
The next potential step will be to test on a conscious animal, which will entail much larger cerebellum signaling across the neural network, causing a vast reduction in the quality of any one motor signal within the cerebellum. The results of this research could eventually lead to important developments in repairing brain damage in humans. However, it has to be taken into account that these results are a long way off, considering that the model used in this experiment was relatively small.