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!
Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo
Full of hot air and proud of it
18.04.2018 | University of Pittsburgh
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
19.04.2018 | Materials Sciences
19.04.2018 | Physics and Astronomy
19.04.2018 | Physics and Astronomy