Partially linearly polarized light is abundant in the oceans. The natural light field is partially polarized throughout the photic range, and some objects and animals produce a polarization pattern of their own. Many polarization-sensitive marine animals take advantage of the polarization information, using it for tasks ranging from navigation and finding food to communication. In such tasks, the distance to which the polarization information propagates is of great importance. Using newly designed polarization sensors, we measured the changes in linear polarization underwater as a function of distance from a standard target. In the relatively clear waters surrounding coral reefs, partial (%) polarization decreased exponentially as a function of distance from the target, resulting in a 50% reduction of partial polarization at a distance of 1.25-3 m, depending on water quality. Based on these measurements, we predict that polarization sensitivity will be most useful for short-range (in the order of meters) visual tasks in water and less so for detecting objects, signals, or structures from far away. Navigation and body orientation based on the celestial polarization pattern are predicted to be limited to shallow waters as well, while navigation based on the solar position is possible through a deeper range.

polarization中文

By working together with the Optical Engineers employed collectively by the MDT, the Smith Lab (Gordon Smith) constructed a novel optogenetic microscope capable of all-optical interrogation of brain networks at the columnar scale.

Polarization

To produce a dynamic blueprint of the functioning brain using new methods for large-scale monitoring and interrogation of neural activity. This goal is well-aligned with a newly-established federal program: Brain Research through Advancing Innovative Neuro-technologies (BRAIN) Initiative, which is aimed at revolutionizing our understanding of the human brain.  Some of our MDT members have already received grants from this highly competitive program.

Elliptical polarization

Learn more about how we engage with the community through internships, research programs and our Seminar Speaker series.

Optical imaging via multi-photon microscopy can measure activity-dependent changes in fluorescent signals directly from individual neurons, astrocytes and blood vessels in the living brain.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Circularlypolarized light

The University of Minnesota's Medical Discovery Team (MDT) on Optical Imaging and Brain Science is a multi-disciplinary effort focused on mapping the detailed circuits that underlie sensation, perception and complex behaviors in the developing and mature brain. State-of-the-art optical imaging and optical stimulation techniques that provide sub-micron spatial resolution will be used in experimental model systems of health, injury and disease. These techniques include two-photon and three-photon imaging and holographic stimulation of individual cells using two-photon optogenetics. Recent advances in optics help preserve the high spatial resolution even when examining multiple brain regions simultaneously. Thus, the activity from large ensembles of cells will provide near complete wiring diagrams underlying specific behaviors in the healthy brain as well as in diseases such as Alzheimer's, epilepsy, autism, stroke, and vascular dementia. Moreover, to create synergy across the MDT’s, researchers in the Optical Imaging MDT may collaborate and lend their technologies to the Addiction MDT and the Nikon University Imaging Center (UIC) core facilitates.

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.