A team of scientists at UCL, University of Cambridge and Radboud University developed an innovative method of studying naturalistic eye movements in mice and discovered similarities and differences with human eye movements.

 

In a study published today in Current Biology, Arne Meyer, John O'Keefe and Jasper Poort used a lightweight eye-tracking system composed of miniature video cameras and motion sensors to record head and eye movements in mice without restricting movement or behaviour. Measurements were made while the animals performed naturalistic visual behaviours including social interactions with other mice and visual object tracking. While the eyes in humans typically move together in the same direction, those in mice often moved in opposite directions. Although humans also make eye movement without head movement, for example when reading a book, the study found that mouse eye movements were always linked to head movement.

The researchers identified two types of mouse eye movement coupled to head movement with different functions: ‘head tilt compensation’ and ‘saccade and fixate’ eye movements. ‘Head tilt compensation’ allows mice to maintain a consistent view of the world by compensating for slow changes in head tilt, and results in the two eyes moving in opposite directions, which is typically not observed in humans. 'Saccade and fixate’ eye movements allow animals to stabilise their view during fast head rotations and shift their gaze in the direction of the head rotation. These ‘saccade and fixate’ movements are similar to those seen in humans and monkeys, which often sample their environment by a sequence of stable images (fixations) and result in the two eyes moving in the same direction. ‘Fixate’ eye movements keep the flow of visual information steady while ‘saccade’ movements allow the animal to select relevant visual information to focus on.

The mouse is an important species to help understand how the human brain functions. First, the organisation and function of the mouse and human brain is similar in many ways, although there are also important differences. Second, scientists can use unique genetic research tools in mice to study brain circuits at a level of detail not possible in other mammals. Third, scientists use genetic tools in mice to model human brain disorders.

The traditional approach to studying vision in humans, monkeys and mice involves restraining head movement. While this facilitates the interpretation of data and allows researchers to use a wider range of experimental measuring methods, it has been unclear whether the results can be generalised to naturalistic behaviours where both head and eyes are free to move. Understanding how mice visually sample their surroundings is also crucial to further close the gap between vision and navigation which has traditionally been studied in freely moving rodents.

This research validates using mice to study important aspects of how humans select visual features that are most important for navigation and decision-making. This visual process is impaired in multiple neurological and neuropsychiatric disorders, including schizophrenia, Alzheimer's disease and stroke. These impairments are currently difficult to treat, and using mice to model these conditions will allow scientists to study the underlying brain mechanisms to help identify and develop new treatments.

This research was funded by the Wellcome Trust, the Gatsby Charitable Foundation and the Royal Society.

Read the full paper in Current Biology: Two Distinct Types of Eye-Head Coupling in Freely Moving Mice. Arne F Meyer, John O’Keefe, and Jasper Poort

https://doi.org/10.1016/j.cub.2020.04.042

https://www.cell.com/current-biology/fulltext/S0960-9822(20)30556-X

 

-Ends-

 

Contact:

Hallie Detrick

Communications Manager, Sainsbury Wellcome Centre, UCL

h.detrick@ucl.ac.uk

 

 

About the Sainsbury Wellcome Centre

The Sainsbury Wellcome Centre (SWC) brings together outstanding experimental neuroscientists who work closely with theorists at the Gatsby Computational Neuroscience Unit (GCNU) to generate and test conceptual frameworks that explain how neural circuits give rise to the fundamental processes underpinning adaptive, flexible behaviour, including perception, memory, expectation, cognition, decisions and action.

The SWC fosters dialogue and collaboration between neuroscientists from within UCL and beyond. Our research environment, international PhD programme, and specialised courses in experimental and computational techniques are designed to equip the next generation of neuroscientists with the knowledge and tools to tackle the big questions in neuroscience.

 

About the Donders Institute

The Donders Institute is a research centre devoted to understanding human cognition and behavior in health and disease. Hundreds of international researchers aim at the advancement of brain-, cognitive and behavioral science and improving health, education and technology.

 

About the University of Cambridge

The mission of the University of Cambridge is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence. To date, 109 affiliates of the University have won the Nobel Prize.

Founded in 1209, the University comprises 31 autonomous Colleges, which admit undergraduates and provide small-group tuition, and 150 departments, faculties and institutions. Cambridge is a global university. Its 19,000 student body includes 3,700 international students from 120 countries. Cambridge researchers collaborate with colleagues worldwide, and the University has established larger-scale partnerships in Asia, Africa and America.

The University sits at the heart of the ‘Cambridge cluster’, which employs 60,000 people and has in excess of £12 billion in turnover generated annually by the 4,700 knowledge-intensive firms in and around the city. The city publishes 341 patents per 100,000 residents.