Skip to content

Oregon study details brain pathways linking visual function, running.

A new study by researchers at the University of Oregon published in the journal Neuron describes a brainstem circuit in mice that may help explain how active movement impacts the way the brain processes sensory information.  Previous studies have examined changes in the visual cortex of mice during running. What was unknown was how do running and vision get linked together in the first place?.

The ‘aha moment’ that inspired the study came five years ago when the team were examining visual perception in mice. They observed that running appeared to be changing how neurons in the brain were firing.  The researchers found that running turned up the magnitude in the mouse’s visual cortex by about two-fold, the signals were basically twice as strong when the mouse was running.

This initial finding, demonstrating a mind-body connection in the mouse visual system, was published in Neuron in 2010. Following up on this finding the team sought to identify neural circuits that could link movement and vision together.

In the current study the researchers focused on the brain’s mesencephalic locomotor region (MLR), which has been shown to mediate running and other forms of activity in many species. They hypothesized that neural pathways originating in the MLR could serve a dual role, sending a signal down to the spinal cord to initiate locomotion, and another up to the cortex to turn up the visual response.

Using optogenetic methods, the team created genetically sensitized neurons in the MLR region of the mouse brain that could be activated by light. The team then recorded the resulting increased visual responses in the cortex. Their results demonstrated that the MLR can indeed lead to both running and increased responsiveness in cortex, and that these two effects could be dissociated, showing that they are conveyed via separate pathways.

Next, researchers activated the terminals of the neurons’ axons in the basal forebrain, a region that sends neuromodulatory projections to the visual cortex. Stimulation here also induced changes in the cortex, but without the intermediary step of running. Interestingly, the basal forebrain is known to use the neuromodulator acetycholine, which is often associated with alertness and attention.

It is unclear whether humans experience heightened visual perception while running, but the study adds to growing evidence that the processes governing active movement and sensory processing in the brain are tightly connected. Similar regions have been targeted in humans for therapeutic deep-brain stimulation to treat motor dysfunction in patients with Parkinson’s disease. Activating this circuit might also provide a means to enhance neuroplasticity, the brain’s capacity to rewire itself.

While it seems that moving and sensing are two independent processes, a lot of new research suggests that they are deeply coupled.  The team hope that their study can help solidify understanding of how the brain functions differently in ‘alert’ states.

Source:  The University of Oregon 

Expression pattern of CamK2-ChR2-YFP viral transfection.  A) Extent of viral expression of CamK2-ChR2-eYFP in the mesencephalic motor locomotor region.  The extent of the largest infection is represented in light green whereas the extent of the smallest injection is in darker green.  Red dots indicate the tip of the optical fibre used to stimulate the MLR.  B)  Confocal image of neurons infected with AAR2/5-CamK2-ChR2-YFP (green) in a VGlut2-tdTomato (red) mouse, showing preferential expression of ChR2 in excitatory neurons.  Scale bar 25 microns.  Niell et al 2014.
Expression pattern of CamK2-ChR2-YFP viral transfection. A) Extent of viral expression of CamK2-ChR2-eYFP in the mesencephalic motor locomotor region. The extent of the largest infection is represented in light green whereas the extent of the smallest injection is in darker green. Red dots indicate the tip of the optical fibre used to stimulate the MLR. B) Confocal image of neurons infected with AAR2/5-CamK2-ChR2-YFP (green) in a VGlut2-tdTomato (red) mouse, showing preferential expression of ChR2 in excitatory neurons. Scale bar 25 microns. Niell et al 2014.

Healthinnovations View All

Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.

Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.

Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio, BioPortfolio.com, the life science, pharmaceutical and healthcare portal.

Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.

Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.

An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.

Leave a Reply

Translate »