Looking into the imagination with mice – how neuroscientists are seeing human vision more clearly

Despite the nursery rhyme about three blind mice, Mouse vision is surprisingly sensitive. Studying the vision of mice has helped researchers discover extraordinary details about how individual brain cells communicate and work together to create a mental picture of the visual world.

I am a neuroscientist Who studies how brain cells operate visual perception and the way these processes can fail under certain conditions such as autism. My lab “hears” the electrical activity of neurons within the outer a part of the brain called the cerebral cortex, A large part of which Processes visual information. Injuries to the visual cortex can result in blindness and other visual deficits, even when the eyes themselves are unaffected.

Understanding the activity of individual neurons—and the way they work together because the brain actively uses and processes information—is a long-standing goal of neuroscience. Researchers have come very near achieving this goal due to latest technologies aimed toward the mouse visual system. And the findings will help scientists higher understand how people’s visual systems work.

Mind within the blink of an eye fixed

Researchers have long thought that vision arose in mice Slower with less clarity. But it seems visual cortex neurons in mice – similar to that They include humans, monkeys, cats and ferrets – Needed Specific visual features to stimulate activity And there are especially Selected in alert and awake situations.

My colleagues and I even have found this Rats are especially susceptible Visual stimuli directly in front of them. This is surprising, because mouse eyes face outward somewhat than forward. Forward-facing eyes, like those of cats and primates, naturally have a bigger area of ​​straight-ahead focus than outward-facing eyes.

This finding suggests that the visual system appears to be specialized to spotlight the frontal visual field shared between mice and humans. For rats, a visible concentrate on what’s straight ahead may help them Responsible for shadows or edges In front of them, helping them avoid predators or betters Hunting and capturing insects for food.

The essential thing is that the middle is the middle It is most affected by aging and many visual diseases Because mice also rely heavily on this a part of the visual field as in humans, they generally is a particularly useful model for studying and treating visual impairment.

A thousand voices make complicated selections

Advances in technology have greatly accelerated scientific understanding of vision and the brain. Researchers can now routinely record the activity of 1000’s of neurons directly and mix that data with real-time video of the mouse’s face, pupils and body movements. This method can Show how behavior interacts with brain activity.

It’s like spending years listening to a grainy recording of a symphony with a featured soloist, but now you have got a pristine recording where you possibly can hear each musician note-by-note with each finger movement.

Using these improved methods, researchers like me are studying how specific forms of neurons work during complex visual behaviors. This involves analyzing how aspects reminiscent of movement, alertness and environment affect visual activity within the brain.

For example, my lab and I discovered that visual signaling has speed Highly sensitive to what action is possible In the physical environment. If a mouse rests on a disk that enables movement, visual signals travel faster to the cortex than if the mouse views the identical images while resting within the stationary tube—even when the mouse is fully occupied in each positions.

To correlate electrical activity with visual perception, researchers also must ask what he thinks. How did we do it?

The past decade has seen researchers debunk the long-standing Myths about mouse learning and behavior. Like other rodents, mice are incredibly intelligent and might learn the right way to “tell” researchers concerning the visual events they perceive through their behavior.

For example, mice can Learn to release the lever to point that they’ve detected that a pattern is vivid or bent. They can Rotate the Lego wheel left or right To move a visible stimulus to the middle of the screen, like in a video game, and so they can Stop running on the wheel And lick the splashes of water When they notice that the visual scene has suddenly modified.

Mice can even use visual cues Focus on their visual processing In specific parts of the visual field. As a result, they will respond more quickly and accurately to visual stimuli displayed in these areas. For example, my team and I discovered that a faint visual image within the peripheral visual field is difficult for mice to detect. But once they notice it — and tell us by licking the water — there are reactions Faster and more accurate.

This improvement comes at a value: If the image unexpectedly appears in a distinct location, the rats are slower and fewer more likely to respond. These results are much like those present in these studies Spatial focus in people.

My lab has found this too Special types of inhibitory neurons – Brain cells that prevent activity from spreading – tightly control the strength of visual signals. When we activated certain inhibitory neurons within the visual cortex of mice, we could effectively “erase” their perception of a picture.

These sorts of experiments are also revealing that there are boundaries between perception and motion within the brain Less distinct than once thought. This signifies that visual neurons will reply to the identical image otherwise in ways in which rely on behavioral conditions – for instance, visual responses are different if the image will likely be Detected successfullyif it appears When the mouse is movingor if it appears When the mouse is thirsty or hydrated.

Understanding how various factors shape how cortical neurons reply to rapid visual images would require advances in computational tools that may separate the contribution of those behavioral signals from visual ones. Researchers also need technologies that may isolate how specific forms of brain cells carry these signals and communicate with them.

Data clouds surround the world

This surge in research on the mouse visual system has resulted in a big increase in the quantity of information that scientists cannot only collect in a single experiment, but additionally publicly share with one another.

Focused on major national and international research centers Unraveling the circuitry of the mouse visual system Leading the charge in launching latest optical, electrical and biological works Tools for measuring large numbers of visual neurons in motion. Moreover, they make All data is publicly availableimpressive Similar efforts around the world. This collaboration accelerates researchers’ ability to research data, replicate results, and make latest discoveries.

Technological advances in data collection and sharing could make the culture of scientific discovery more efficient and transparent. Data Informatics Objective of neuroscience in the next years.

If the past 10 years are anything to go by, I imagine that discoveries like these are only the tip of the iceberg, and that the mighty and really blind mouse will play a very important role in the continued struggle to grasp the mysteries of the human brain.