The magnetic sense

Why powerlines confuse the internal compass

2012-07-11

(Press-News.org) Migratory birds and fish use the Earth's magnetic field to find their way. LMU researchers have now identified cells with internal compass needles for the perception of the field – and can explain why high-tension cables perturb the magnetic orientation.

Although many animal species can sense the geomagnetic field and exploit it for spatial orientation, efforts to pinpoint the cells that detect the field and convert the information into nerve impulses have so far failed. "The field penetrates the whole organism, so such cells could be located almost anywhere, making them hard to identify," says LMU geophysicist Michael Winklhofer. Together with an international team, he has located magnetosensory cells in the olfactory epithelium of the trout.

The researchers first used enzymes to dissociate the sensory epithelium into single cells. The cell suspension was then stimulated with an artificial, rotating magnetic field. This approach enabled the team to identify and collect single magnetoresponsive cells, and characterize their properties in detail. Much to Winklhofer's surprise, the cells turned out to be more strongly magnetic than previously postulated - a finding that explains the high sensitivity of the magnetic sense.

Magnetite crystals show the way

The cells sense the field by means of micrometer-sized inclusions composed of magnetic crystals, probably made of magnetite. The inclusions are coupled to the cell membrane, which is necessary to change the electrical potential across the membrane when the crystals realign in response to a change in the ambient magnetic field. "This explains why low-frequency magnetic fields generated by powerlines disrupt navigation relative to the geomagnetic field and may induce other physiological effects," says Winklhofer.

The new findings could lead to advances in the sphere of applied sciences, for example in the development of highly sensitive magnetometers. In addition, they raise the question of whether human cells are capable of forming magnetite and if so, how much. "If the answer to the question is yes", Winklhofer speculates, "intracellular magnetite would provide a concrete physiological substrate that could couple to so-called electrosmog". (PNAS, 9. July) (göd)

### Publication: Magnetic characterization of isolated candidate vertebrate magnetoreceptor cells. S.H.K. Eder, H. Cadiou, A. Muhamad, P. A. McNaughton, J. L. Kirschvink, M. Winklhofer. www.pnas.org/cgi/doi/10.1073/pnas.1205653109

Contact: Michael Winklhofer
Division of Geophysics
Department of Earth and Environmental Sciences
LMU Munich
Phone: +49 (89) 2180-4207
Fax: +49 (89) 2180-4205
Email: Michael.winklhofer@geophysik.uni-muenchen.de
Web: http://www.geophysik.uni-muenchen.de/Members/michael

ELSE PRESS RELEASES FROM THIS DATE:

Rare glimpse into the origin of species

2012-07-11

A new species of monkey flower, created by the union of two foreign plant species, has been discovered on the bank of a stream in Scotland. Genetic changes in this attractive yellow-flowered hybrid have allowed it to overcome infertility and made it a rare example of a brand new species that has originated in the wild in the last 150 years. Thousands of wild species and some crops are thought to have originated in this way, yet only a handful of examples exist where this type of species formation has occurred in recent history. The ancestors of the new plant were brought ...

Scientists at the Mainz University Medical Center gain new insights into Taspase1 function

2012-07-11

Scientists at the University Medical Center of Johannes Gutenberg University Mainz in Germany identified a novel strategy to target the oncologically relevant protein-cleaving enzyme Taspase1. Taspase1 levels are not only elevated in cancer cells of patients with head and neck tumors and other solid malignancies but the enzyme is also critical for the development of leukemias. Central to this concept is the approach to inhibit the enzyme's activity by 'gluing together' individual Taspase1 molecules. The results of a study undertaken by Professor Dr. Roland Stauber of the ...

Preclinical studies use specialized ultrasound to detect presence of cancer

2012-07-11

From the air, the twists and turns of rivers can easily be seen. In the body, however, tracing the twists and turns of blood vessels is difficult, but important. Vessel "bendiness" can indicate the presence and progression of cancer. This principle led UNC scientists to a new method of using a high-resolution ultrasound to identify early tumors in preclinical studies. The method, based on vessel bendiness or "tortuosity," potentially offers an inexpensive, non-invasive and fast method to detect cancer that could someday help doctors identify cancers when tumors are ...

Nutrient mixture improves memory in patients with early Alzheimer's

2012-07-11

CAMBRIDGE, MA -- A clinical trial of an Alzheimer's disease treatment developed at MIT has found that the nutrient cocktail can improve memory in patients with early Alzheimer's. The results confirm and expand the findings of an earlier trial of the nutritional supplement, which is designed to promote new connections between brain cells. Alzheimer's patients gradually lose those connections, known as synapses, leading to memory loss and other cognitive impairments. The supplement mixture, known as Souvenaid, appears to stimulate growth of new synapses, says Richard Wurtman, ...

First-of-its-kind approach nanomedicine design effectively targets cancer with decreased toxicity

2012-07-11

BOSTON, MA—Researchers at Brigham and Women's Hospital (BWH) are the first to report a new approach that integrates rational drug design with supramolecular nanochemistry in cancer treatment. Supramolecular chemistry is the development of complex chemical systems using molecular building blocks. The researchers utilized such methods to create nanoparticles that significantly enhanced antitumor activity with decreased toxicity in breast and ovarian cancer models. "This work is effectively moving beyond using nanotechnology as drug 'delivery' vehicles to reengineering ...

Mapping out growth for the UK space sector: UK Space Agency publishes its Civil Space Strategy

2012-07-11

The 'Civil Space Strategy' setting out the direction for the UK space sector over the next four years has been launched today, Tuesday 10th July, at the Farnborough International Airshow. The Strategy sets out the UK Space Agency's framework supporting the growth of the sector over the next four years. The Civil Space Strategy was formally launched by the Minister for Universities and Science to the international space community, gathered for Space Day at Farnborough. David Willetts discussed the Strategy in his speech to the Space Conference as well as revealing the ...

Doctors overlook chemical illnesses, study finds

2012-07-11

SAN ANTONIO (July 10, 2012) — Chemical intolerance contributes to the illnesses of 1 in 5 patients but the condition seldom figures in their diagnosis, according to clinical research directed by a UT Medicine San Antonio physician. Clinical tools are available to identify chemical intolerance but health care practitioners may not be using them, lead author David Katerndahl, M.D., M.A., said. The study is in the July 9 issue of Annals of Family Medicine. UT Medicine is the clinical practice of the School of Medicine at The University of Texas Health Science Center San ...

Interactive personal health records increase clinical preventive services

2012-07-11

Richmond, Va. (July 9, 2012) – Patients who use an interactive personal health record (IPHR) are almost twice as likely to be up to date with clinical preventive services as those who do not, according to a new study led by Alex Krist, M.D., M.P.H., research member of the Cancer Prevention and Control program at Virginia Commonwealth University Massey Cancer Center. Published today in the journal Annals of Family Medicine, the randomized controlled trial involved eight primary care practices and 4,500 patients. The patients were divided into a control group and an intervention ...

Rising carbon dioxide in atmosphere also speeds carbon loss from forest soils, IU-led research finds

2012-07-11

BLOOMINGTON, Ind. -- Elevated levels of atmospheric carbon dioxide accelerate carbon cycling and soil carbon loss in forests, new research led by an Indiana University biologist has found. The new evidence supports an emerging view that although forests remove a substantial amount of carbon dioxide from the atmosphere, much of the carbon is being stored in living woody biomass rather than as dead organic matter in soils. Richard P. Phillips, lead author on the paper and an assistant professor of biology in the IU College of Arts and Sciences, said that after nearly ...

New survey shows patient concerns and misinformation impede treatment of menopausal women

2012-07-11

Chevy Chase, MD – The Endocrine Society commissioned Lake Research Partners to conduct a national survey of 424 internal medicine, family practice and OB/GYN physicians about their attitudes and experiences related to treating menopausal symptoms. According to the survey, physicians say the primary barrier to women receiving hormone therapy is patients' fears about the risks and their unwillingness to discuss the option. This new survey follows a study conducted in April 2012 among 810 women ages 45 to 60 on the same topic. Hormone therapy has been under intense scrutiny ...

Measurable residual disease shows strong potential as an early indicator of survival in patients with acute myeloid leukemia

Chemotherapy and radiation are comparable as pre-transplant conditioning for patients with b-acute lymphoblastic leukemia who have no measurable residual disease

The magnetic sense

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: