DESIGN
Using Biomimetic Implants to
Restore Lost Functions
Building on advances in brain-computer interface technology and computational biology, the ReNaChip
project lays the groundwork for the use of a prosthetic chip to recover function to nervous system deficiencies.
A. Silmon, INEX, Newcastle University, Newcastle-Upon-Tyne, UK
Behavioural rehabilitation
The use of biomimetic implants that
mimic the biological world to replace
lost pathways in the brain provides a
tremendous opportunity to develop
innovative therapy for neurode-
generative disease and injury.
Supported by the EC Seventh
Framework programme for
future and emerging technolo-
gies, the ReNaChip project
aims to develop and test the
feasibility of a novel approach
to behavioural rehabilitation
in an aging model: a synthetic
biomimetic chip is interfaced
with the brain to complete a well-
defined neuronal circuit rendered
dysfunctional by the aging process.
Synthetic cerebellum
Information and
signal processing
Synthetic
integration
Recording
electrode
Stimulation
rehabilitation of central nervous system
deficiency beyond the direct DBS approach.
We believe that the use of biomimetic
implants provides a tremendous
opportunity to recover function to
a range of nervous system defi-
ciencies. Our aim is to create
a synthetic biomimetic model
of the brain microcircuit
associated with the motor
eye-blink learning response
and to implement this in a
microchip. The device will
be integrated with an animal
model to create a biohybrid in
which a lost motor function is
replaced (Figure 1).
Biohybrids and the brain-computer interface
As our understanding of how the brain
works increases and advances are made
in computing and electronics, there is
increasing interest in the integration of
biology and technology. The ability to
provide direct communication between
the nervous system and an artificial device
is being used to restore damaged hearing
(cochelar implants), sight (retinal implants)
and movement (neuroprosthetics).
Deep brain stimulation (DBS), whereby
the brain is stimulated directly by implanted electrodes, has been shown to be
effective in ameliorating the symptoms of
Clinical integration
The cerebellar microcircuit
The motor eye-blink learning response
is an example of a conditioned behav-
iour that takes place in a location in the
brain called the cerebellum. Through
repeated exposure to a noise or tone (a
conditioned stimulus or CS) followed
by an air puff to the eye (an unconditioned
stimulus or US), an animal will learn to
predict the unconditioned stimulus when
it hears the tone and will close the eye
in response to the noise (a conditioned
response or CR). The ability to learn this
behaviour is lost during the aging process.
While the performance of the cerebellum is
compromised, the inputs and outputs of the
responsible microcircuit remain functional.
Replacing the deficient part of the neural
FIGURE 1: Schematic of the closed-loop ReNaChip approach.
Parkinson’s disease, chronic pain, tremor
and dystonia. However, this method for
replacing lost brain function is not applicable to all neurological disease, as it lacks
the required specificity to manipulate local,
defined circuits within the brain.
The ReNaChip approach
Recent developments in brain computer
interface (BCI) and in computational
biology have led to innovations in the
