Understanding the mechanisms by which the brain functions is one of the most complex challenges in science. One important aspect is the electrical conduction of stimuli in nerve cells.
In order to study neuronal circuits, a sharp metal electrode is usually inserted into the brain to introduce a current. However, the response does not reflect the highly complex activation patterns of natural nerve stimuli. In addition, the direct current applied in this fashion causes damage to tissue through undesired electrochemical side reactions.
Collaboration between neuroscientists and nanomaterials researchers at Case Western Reserve University (Cleveland, Ohio, USA) has resulted in the development of a technique that is both gentler and elicits more natural nerve impulses. As reported in the journal Angewandte Chemie, the technique is based on a micropipette coated with semiconductor nanoparticles that activates neurons in brain tissue with visible or infrared (IR) light. In contrast to conventional electrodes, these photoelectrodes require neither wires nor electrical power.
The team led by Ben W. Strowbridge and Clemens Burda coated the interiors of extremely finely drawn-out glass micropipettes with lead selenide nanoparticles. Lead selenide is a semiconductor that is activated by IR light. As in solar cells, irradiation “catapults” firmly bound electrons out of the valence band and into the conduction band of the semiconductor, where they can move freely. This leads to charge separation and thus to an electrical potential. With a suitable laser, defined processes elicited by short light pulses set off corresponding electrical pulses in the micropipette. An electrical field is thus formed around the pipette, which can then be used by the researchers to stimulate neurons in rat brain samples with a high degree of time-resolution. Measuring electrodes could then be used to record the natural activation patterns of very similar nerve impulses.
Samples of the olfactory bulb (a region of the brain involved in processing smell) and the hippocampus (part of the cerebrum important in the transfer of contents from short-term to the long-term memory) were examined. Neither toxic effects nor damage to the nerve cells were observed after repeated stimulation.
By using these new photoelectrodes, the cooperation of nerve cells can be studied. However, therapeutic applications are also possible: the probes could be used to activate individual regions of the brain or damaged or cut nerves to restore function – without the need for disturbing wires.
Author: Clemens Burda, Case Western Reserve University, Cleveland (USA), http://www.case.edu/nanobook/pages/faculty/cburda.htm
Title: Wireless Activation of Neurons in Brain Slices Using Nanostructured Semiconductor Photoelectrodes
Angewandte Chemie International Edition 2009, 48, No. 13, doi: 10.1002/anie.200806093
Clemens Burda | Angewandte Chemie
Further reports about: > Activation of neurons > Angewandte Chemie > Hippocampus > Semiconductor > electrical conduction > electrical power > electrochemical side reactions > micropipette > nerve cells > nerve impulses > neuronal circuits > photoelectrodes > semiconductor nanoparticles > semiconductor photoelectrodes > similar nerve impulses
A cell senses its own curves: New research from the MBL Whitman Center
29.04.2016 | Marine Biological Laboratory
A New Discovery in the Fight against Cancer: Tumor Cells Switch to a Different Mode
29.04.2016 | Universität Basel
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...
As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.
Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
29.04.2016 | Physics and Astronomy
29.04.2016 | Health and Medicine
29.04.2016 | Life Sciences