Findings, in mice, fuel the idea that processes of active movement and sensory processing are connected
A new study by researchers at the University of Oregon published today 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.
Christopher Niell, a biologist and member of the University of Oregon's Institute of Neuroscience, directed a team that provided new details in the journal Neuron about a brainstem circuit in mice that may help explain how active movement impacts the way the brain processes sensory information.
Credit: University of Oregon
"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?" said Cristopher Niell, a biology professor in the Institute of Neuroscience and the senior author on the paper "Identification of a Brainstem Circuit Regulating Visual Cortical State in Parallel with Locomotion."
The "aha moment" that inspired the study came five years ago when Niell, as a postdoctoral fellow in Michael Stryker's lab at the University of California, San Francisco, was examining visual perception in mice. He observed that running appeared to be changing how neurons in the brain were firing.
"We 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," Niell said.
This initial finding, demonstrating a mind-body connection in the mouse visual system, was published in Neuron in 2010. Following up on this finding, Niell's team sought to identify neural circuits that could link movement and vision together.
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 the 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.
Niell's team included Moses Lee, a visiting scholar at the UO and student in the M.D.-Ph.D. program at UC-San Francisco, who served as the lead author on the paper. "While it seems that moving and sensing are two independent processes, a lot of new research suggests that they are deeply coupled," Lee said. "My hope is that our study can help solidify our understanding of how the brain functions differently in 'alert' states."
Other authors were Jennifer Hoy of the UO, Antonello Bonci of the National Institute of Drug Abuse and Johns Hopkins School of Medicine, Linda Wilbrecht of the UC-Berkeley, and Stryker. Research in the Niell lab at the UO was conducted over the past three years with funding from the National Institutes of Health. NIH grants supporting the research were 1R01EY023337 to Niell, 1R01EY02874 to Stryker and 1RC2NS069350 and 1R01MH087542 to Wilbrecht.
About the University of Oregon The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.
Source: Cristopher Niell, assistant professor, Department of Biology, 541-346-8598, firstname.lastname@example.org
Niell faculty page: http://uoneuro.uoregon.edu/ionmain/htdocs/faculty/niell.html
Institute of Neuroscience: http://uoneuro.uoregon.edu/ionmain/htdocs/index.html
Department of Biology: http://biology.uoregon.edu/
University of Oregon: http://uoregon.edu/
Like UO Science on Facebook: http://www.facebook.com/UniversityOfOregonScience
Follow UO Science on Twitter: https://twitter.com/UO_Research Note: The University of Oregon is equipped with an on-campus television studio with a point-of-origin Vyvx connection, which provides broadcast-quality video to networks worldwide via fiber optic network. In addition, there is video access to satellite uplink, and audio access to an ISDN codec for broadcast-quality radio interviews.
Lewis Taylor | Eurek Alert!
Orang-utan females prefer cheek-padded males
02.09.2015 | Max Planck Institute for Evolutionary Anthropology, Leipzig
VIMS reports intense and widespread algal blooms
02.09.2015 | Virginia Institute of Marine Science
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...
The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.
Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...
Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
02.09.2015 | Physics and Astronomy
02.09.2015 | Trade Fair News
02.09.2015 | Life Sciences