Scientists Amazingly Discover How to Control the Brain with Light

Exciting new method will eliminate surgery

Have you ever heard of optogenetics?

It is an exciting new neurotech that experts are excited about.

Optogenetics is a technology that controls the brain by using different frequencies of light. It has blended both engineering and neurobiology to activate the workings of how brain neurons function naturally.

What optogenetics can offer

In just a decade, scientists showed the ability to decipher brain signals associated with pain, artificially insert memories in mice, crack the neural codes for addiction, renew rudimentary sight in blind mice, reverse depression, and even replace bad memories with good ones.

While optogenetics has proven to be the brain’s programming language. However, this exciting new neurotech does have two downfalls: 1) it require surgery to insert optical fibers in the brain, and 2) gene therapy is needed.

An exciting new version of optogenetics

Recently, the person who created optogenetics has returned with a significant new update. This person is Dr. Karl Deisseroth. His Stanford University team, who collaborated with the University of Minnesota, presented this new upgraded version of optogenetics that controls brain behavior without surgery.

This new system penetrated deep into the brains of mice. And with light pulses, this fantastic team altered the likelihood of how mice have seizures and were able to reprogram their brain to be more sociable.

The real key to successfully applying optogenetics lies in genetic engineering.
However, looking ahead, the study is a sure-footed step towards transforming a powerful research technology into a clinical therapy that could help people with neurological problems, such as depression or epilepsy. We are still far from that vision - but the study suggests it’s science fiction potentially within reach.

The inner workings of optogenetics

The inner workings of optogenetics

To comprehend the workings of optogenetics, one must first understand how brains function. Neurons in our brains operate on electricity and chemistry. Brain cells are like storage containers with doors - which are called ion channels. These containers are what protect the cell from the outside world.

Whenever signals are strong enough, these doors to the cells will open inwardly or outwardly. Electrical currents are generated from this process and the current moves through a biological network. The electrical data transforms into chemicals that move across a gap between neurons - delivering messages to neighboring neurons.

This is the process of how neurons communicate in a network. More specifically, this is how neuro networks create emotions, memories, and behaviors.

Optogenetics provides a shortcut for this process

By using viruses, scientists can add a gene for opsins into living neurons. Opsins are unique cell doors that will open when it sees specific frequencies of light pulses, which normal brain cells cannot do.

When opsins were added to mouse neurons, they essentially had a superpower in responding to light frequencies. In the original version of optogenetics, scientists would insert optical fibers to enhance the light stimulation. Computer-programmed light pulses can target these newly light-sensitive neurons in specific brain regions and subsequently control their activity.

When genetic engineering is applied, it allows scientists to fine-tune which neuron populations get that more power. This is how a bad memory can be changed or how depression could be reversed. The real power of optogenetics is through this neural selectivity.

No more surgery

The main objective of Deisseroth’s new study was to eliminate surgical implants. This is a real challenge. It requires that these bioengineered brain neurons need opsin doors that are both sensitive and powerful enough to respond to light - even if that light is diffused by brain tissue and the skull.

However, the research team already had a candidate called ChRmine. This opsin possesses a fantastic ability to react quickly to light and generate a huge electrical current in neurons 100 times more than any other candidate.

ChRmine is also sensitive, allowing just a spark of light at the preferred wavelength to open its doors and control neural activity. Perhaps the best trait of ChRmine is how it rapidly shuts after it opens, which gives more control to the process and protects against overstimulation.

Testing the new version of optogenetics

During its first test, viruses were used to add ChRmine deep inside the brain - the ventral tegmental area (VTA) - which controls how reward and addiction are processed and controls depression. Up to now, the only way to achieve this in clinical settings was through an implanted electrode.

In a more complex test, the team applied this method to a population of brain cells in the brain’s base. These were cells that influence social behavior and how much one enjoys and seeks social interaction.

They discovered that the mice with ChRmine-enhanced cells were more apt to spend time in the ‘social zone’ of their chamber than their colleagues who didn’t have ChRmine. This means that the research team could change a socially ambivalent mouse into a social butterfly - using just a few light beams and no open-brain surgery.