Research - Neural Implants
How do brain cells communicate?
The average adult human brain is made up of about 100 billion brain cells! Brain cells, which are also called neurons, communicate via the conduction of electrical currents called action potentials. An action potential is an electrical charge which travels from one neuron to another. A brain cell is said to “fire” when an action potential is transmitted from that brain cell to another. Brain cells are connected by junctions in the brain called synapses. A synapse is a connection between two or more different neurons. The synapse is very important because without it our brain cells would not communicate! A single neuron may have up to 15,000 synapses, allowing signals from many different neurons to converge on one neuron. Neurons can have many synapses in order to enable the very precise tuning of brain activity to fit our very complicated daily activities as a human.
Neurons communicate in two ways – through chemical synapses and electrical synapses. Electrical synapses are also called “gap junctions.” Chemical and electrical synapses allow brain cells to transmit information to each other. In electrical neurotransmission, action potentials pass through gap junctions through the principles of electrical conduction. Electrical synapses involve the movement of electrical charge from one neuron to another. In chemical neurotransmission, a neuron releases neurotransmitter molecules which are picked up by an adjacent brain cell.
What happens when the brain cells do not communicate properly?
In some people, including patients of Parkinson’s disease, brain cells do not function as well as they should. This leads to problems. Parkinson’s disease patients cannot move normally because their brain does not produce enough of the neurotransmitter dopamine. Therefore, the chemical synapses of Parkinson’s patients do not communicate as well as they should. A new technology called Deep Brain Stimulation involves placing an electrical stimulator in a region of the brain called the substantia nigra. In healthy individuals, the substantia nigra is rich with the neurotransmitter dopamine. In Parkinson’s patients, a Deep Brain Stimulator is surgically implanted in the patient’s brain in order to stimulate the release of dopamine. The deep brain stimulator produces a stimulating electrical charge which improves the transmission of action potentials between neurons. Deep brain stimulators can also improve the brain’s function by reducing or inhibiting the electrical activity of neurons. Parkinson’s patients with deep brain stimulation are better able to move and perform their everyday activities because their dopamine neurons are electrically stimulated to produce action potentials.
What is a neural implant?
A neural implant is a small chip or other device which is implanted directly in a person’s brain. Brain implants can electrically stimulate, block, or record signals from single neurons or groups of neurons in the brain. Such an implantable device would convert brain cells into electronic signals and be able to change the brain’s functioning.
How can neural implants change the way your brain works?
A neural implant could provide foundation for new therapies that could help people who cannot see or who cannot hear by feeding their brains visual or auditory information. A blind person could get a neural implant to enhance the functioning of their visual cortex, enabling them to see better. A military veteran with post-traumatic stress disorder could use a neural implant to reduce the severity of their Post-Traumatic Stress Disorder symptoms.
Brain implants to improve sensory function already exist. Some people who are deaf may be able to improve their auditory function by getting a cochlear implant. Cochlear implants are implanted devices placed directly on the cochlea to stimulate the auditory nerve. A cochlear implant is composed of several smaller devices including a microphone, a speech processor, a transmitter and receiver/stimulator, and an electrode array. The microphone picks up sound, and the speech processor selects and arranges sounds picked up by microphone. Then, the transmitter and receiver/stimulator convert the sounds into electric impulses that the auditory nerve will recognize as sound. The electrode array is a group of electrodes that collects the impulses from the auditory nerve stimulator and sends them to the appropriate parts of the auditory nerve. While a cochlear implant does not restore normal hearing, it can provide a deaf person with a normal representation of sounds in the environment and help them understand speech.
Why can’t I get a brain implant to get smarter right now?
Unfortunately, scientists do not know enough about how the human brain communicates on the level of individual neurons or even small groups of neurons to be able to modulate human brain activity through electrical stimulation or inhibition with a computer chip. Scientists also do not know how the brain codes complex information, and the placement of a chip in one’s brain could trigger serious brain inflammation which could cause very severe neurological problems. The Defense Advanced Research Projects Agency, who is working on an implantable brain chip, acknowledges that it could be several decades away. In order for it to be possible to develop such a brain chip, advances in science, medical devices manufacturing, and electronics are necessary before the device could be used.
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