Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

GPS in the head? RUB scientist deciphers frequency of cell activity

15.09.2011
Rhythmic activity of neurons to code position in space / Journal of Neuroscience: RUB scientist deciphers frequency of cell activity

Prof. Dr. Motoharu Yoshida (Ruhr-Universität Bochum, RUB) and colleagues from Boston University investigated how the rhythmic activity of nerve cells supports spatial navigation.

The research scientists showed that cells in the entorhinal cortex, which is important for spatial navigation, oscillate with individual frequencies. These frequencies depend on the position of the cells within the entorhinal cortex. “Up to now people believed that the frequency is modulated by the interaction with neurons in other brain regions”, says Yoshida. “However, our data indicate that this may not be the case. The frequency could be fixed for each cell. We may need new models to describe the contribution of rhythmic activity to spatial navigation.” The researchers report in the Journal of Neuroscience.

Rhythmic brains find their way

„The brain seems to represent the environment like a map with perfect distances and angles“, explains Yoshida. “However, we are not robots with GPS systems in our head. But the rhythmic activity of the neurons in the entorhinal cortex seems to create a kind of map.” The activity of individual neurons in this brain region represents different positions in space. If an animal is in a certain location, a certain neuron fires. The rhythmic activity of each cell may enable us to code a set of positions, which form a regular grid. Computer simulations of previous studies suggested that signals from cells in other brain regions influence the rhythmic activity of the entorhinal neurons. Using electrophysiological recordings in rats and computer simulations, Yoshida and his colleagues examined the nature of this influence.

Expressing the cellular rhythm in numbers

In order to simulate the input signals from other cells, Yoshida and his colleagues varied the voltage at the cell membrane (membrane potential). A change of the membrane potential from the resting state to more positive values thereby resembled an input signal from another cell. The membrane potential of the cells in the entorhinal cortex is not constant, but increases and decreases periodically; it oscillates. The scientists determined how fast the membrane potential changed (frequency) and how large the differences in these changes were (amplitude), when they shifted the mean membrane potential around which the potential oscillated.

Position determines the frequency

In the resting state, the membrane potential oscillations of the entorhinal cells were weak and in a broad frequency range. If the membrane potential was shifted to more positive values, thus mimicking the input of another cell, the oscillations became stronger. Additionally, the membrane potential now fluctuated with a distinct frequency, which was dependent on the position of the cell within the entorhinal cortex. Cells in the upper portion of this brain region showed oscillations with higher frequency than cells in the lower portion. However, the frequency was independent of further changes in membrane potential and thus largely independent of input signals from other cells.

Bibliographic record

Yoshida, M., Giocomo, L.M., Boardman, I., Hasselmo, M.E. (2011) Frequency of Subthreshold Oscillations at Different Membrane Potential Voltages in Neurons at Different Anatomical Positions on the Dorsoventral Axis in the Rat Medial Entorhinal Cortex, The Journal of Neuroscience, 31, 12683–12694, doi: 10.1523/JNEUROSCI.1654-11.2011

Further information

Prof. Dr. Motoharu Yoshida, Neural Dynamics Lab, Fakultät für Psychologie der Ruhr-Universität, 44780 Bochum, Tel.: 0234/32-27138

motoharu.yoshida@rub.de

Editor: Dr. Julia Weiler

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de/

More articles from Life Sciences:

nachricht Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>