Researchers from the Netherlands Institute for Neuroscience found that the superior colliculus, a brain region preserved throughout evolution, plays a more vital role in vision than previously believed.
When we look at something, we can easily distinguish an object from the background. While this sounds obvious, how our brain accomplishes it is still quite complicated. It has long been known that a brain area called the visual cortex is involved in the process. Yet there are animals in which this area is much less developed than ours or does not exist at all. So how do these animals see when a prey or predator approaches them in a crowded background? Could another player be involved after all?
Visual information travels from our retina to the visual cortex, but also partly to a structure called the superior colliculus. This is the ancient visual system common to all classes of vertebrates, from fish to amphibians, reptiles, birds, and mammals. Remarkably, this structure has been preserved throughout evolution, but varies greatly in relative size between different organisms. For example, the superior colliculus is relatively large in fish and birds whereas it is just a tiny pea tucked away in grey matter in humans.
Two parallel paths
To find out exactly what the superior colliculus does, Leonie Cazemier and her colleagues from Alexander Heimel’s and Pieter Roelfsema’s groups studied mice and their ability to distinguish objects from the background. The mouse is an interesting model because, like in humans, its brain has two parallel pathways: both the visual cortex and the superior colliculus. The mice were trained to distinguish figures from a background, which appeared on the left or right side of the image. By licking either left or right, the mice reported on which side the image had appeared.
Alexander Heimel: “Previous research already showed that a mouse can still complete the task if you turn off its visual cortex, which suggests that there is a parallel pathway for visual object detection. In this study, we switched off the superior colliculus using optogenetics to see what effect that would have. Contrary to the previous study, the mice became worse at detecting the object, indicating that the superior colliculus plays an important role during this process. Our measurements also showed that information about the visual task is present in the superior colliculus, and that this information is less present the moment a mouse makes a mistake. So, its performance in the task correlates with what we’re measuring.”
Function in humans
“How this works in humans is not entirely clear yet. Although humans also have two parallel systems, their visual cortex is much more developed. The superior colliculus may therefore play a less important role in humans. It is known that the moment someone starts waving, the superior colliculus directs your gaze there. It is also striking that those who are blind with a double lesion in the visual cortex do not see anything consciously but can often still navigate and avoid objects. Our research shows that the superior colliculus might be responsible for this and may therefore be doing more than we thought.”
Reference: “Involvement of superior colliculus in complex figure detection of mice” by J Leonie Cazemier, Robin Haak, TK Loan Tran, Ann TY Hsu, Medina Husic, Brandon D Peri, Lisa Kirchberger, Matthew W Self, Pieter Roelfsema and J Alexander Heimel, 25 January 2024, eLife.
DOI: doi:10.7554/eLife.83708

News
Johns Hopkins Researchers Uncover a New Way To Kill Cancer Cells
A new study reveals that blocking ribosomal RNA production rewires cancer cell behavior and could help treat genetically unstable tumors. Researchers at the Johns Hopkins Kimmel Cancer Center and the Department of Radiation Oncology and Molecular [...]
AI matches doctors in mapping lung tumors for radiation therapy
In radiation therapy, precision can save lives. Oncologists must carefully map the size and location of a tumor before delivering high-dose radiation to destroy cancer cells while sparing healthy tissue. But this process, called [...]
Scientists Finally “See” Key Protein That Controls Inflammation
Researchers used advanced microscopy to uncover important protein structures. For the first time, two important protein structures in the human body are being visualized, thanks in part to cutting-edge technology at the University of [...]
AI tool detects 9 types of dementia from a single brain scan
Mayo Clinic researchers have developed a new artificial intelligence (AI) tool that helps clinicians identify brain activity patterns linked to nine types of dementia, including Alzheimer's disease, using a single, widely available scan—a transformative [...]
Is plastic packaging putting more than just food on your plate?
New research reveals that common food packaging and utensils can shed microscopic plastics into our food, prompting urgent calls for stricter testing and updated regulations to protect public health. Beyond microplastics: The analysis intentionally [...]
Aging Spreads Through the Bloodstream
Summary: New research reveals that aging isn’t just a local cellular process—it can spread throughout the body via the bloodstream. A redox-sensitive protein called ReHMGB1, secreted by senescent cells, was found to trigger aging features [...]
AI and nanomedicine find rare biomarkers for prostrate cancer and atherosclerosis
Imagine a stadium packed with 75,000 fans, all wearing green and white jerseys—except one person in a solid green shirt. Finding that person would be tough. That's how hard it is for scientists to [...]
Are Pesticides Breeding the Next Pandemic? Experts Warn of Fungal Superbugs
Fungicides used in agriculture have been linked to an increase in resistance to antifungal drugs in both humans and animals. Fungal infections are on the rise, and two UC Davis infectious disease experts, Dr. George Thompson [...]
Scientists Crack the 500-Million-Year-Old Code That Controls Your Immune System
A collaborative team from Penn Medicine and Penn Engineering has uncovered the mathematical principles behind a 500-million-year-old protein network that determines whether foreign materials are recognized as friend or foe. How does your body [...]
Team discovers how tiny parts of cells stay organized, new insights for blocking cancer growth
A team of international researchers led by scientists at City of Hope provides the most thorough account yet of an elusive target for cancer treatment. Published in Science Advances, the study suggests a complex signaling [...]
Nanomaterials in Ophthalmology: A Review
Eye diseases are becoming more common. In 2020, over 250 million people had mild vision problems, and 295 million experienced moderate to severe ocular conditions. In response, researchers are turning to nanotechnology and nanomaterials—tools that are transforming [...]
Natural Plant Extract Removes up to 90% of Microplastics From Water
Researchers found that natural polymers derived from okra and fenugreek are highly effective at removing microplastics from water. The same sticky substances that make okra slimy and give fenugreek its gel-like texture could help [...]
Instant coffee may damage your eyes, genetic study finds
A new genetic study shows that just one extra cup of instant coffee a day could significantly increase your risk of developing dry AMD, shedding fresh light on how our daily beverage choices may [...]
Nanoneedle patch offers painless alternative to traditional cancer biopsies
A patch containing tens of millions of microscopic nanoneedles could soon replace traditional biopsies, scientists have found. The patch offers a painless and less invasive alternative for millions of patients worldwide who undergo biopsies [...]
Small antibodies provide broad protection against SARS coronaviruses
Scientists have discovered a unique class of small antibodies that are strongly protective against a wide range of SARS coronaviruses, including SARS-CoV-1 and numerous early and recent SARS-CoV-2 variants. The unique antibodies target an [...]
Controlling This One Molecule Could Halt Alzheimer’s in Its Tracks
New research identifies the immune molecule STING as a driver of brain damage in Alzheimer’s. A new approach to Alzheimer’s disease has led to an exciting discovery that could help stop the devastating cognitive decline [...]