Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tarantula Toxin is Used to Report on Electrical Activity in Live Cells

21.10.2014

MBL Neurobiology Course Students Contribute to Probe’s Development
With Scientists from UC-Davis and Lawrence Berkeley National Laboratory

Crucial experiments to develop a novel probe of cellular electrical activity were conducted in the Neurobiology course at the Marine Biological Laboratory (MBL) in 2013. Today, that optical probe, which combines a tarantula toxin with a fluorescent compound, is introduced in a paper in the Proceedings of the National Academy of Sciences.


The movie is quantitative imaging of cells with potassium channels, bathed in dilute fluorescent tarantula toxin. Pixel color indicates intensity of tarantula toxin concentration. The circular shapes are cell surfaces, illuminated by tarantula toxins bound to potassium channels. The cell on the right is electrically stimulated to the indicated voltages. The cells on the left remain at constant resting voltage. Intensity change reports activation of potassium channels. At -100 mV channels are at rest. During stimulus to 0 mV channels activate and fluorescence decreases as tarantula toxins fall off of potassium channels. Upon return to -100 mV, tarantula toxins find the resting channels again.

The lead authors of the paper are Drew C. Tilley of University of California-Davis and the late Kenneth Eum, who was a teaching assistant in the Neurobiology course and a Ph.D. candidate at UC-Davis.

The probe takes advantage of the potent ability of tarantula toxin to bind to electrically active cells, such as neurons, while the cells are in a resting state. The team discovered that a trace amount of toxin combined with a fluorescent compound would bind to a specific subset of voltage-activated proteins (Kv2-type potassium ion channels) in live cells. The probe lights up cell surfaces with this ion channel, and the fluorescent signal dims when the channel is activated by electrical signals.

This is the first time that researchers have been able to visually observe these ion channels “turning on” without first genetically modifying them. All that is required is a means to detect probe location, suggesting that related probes could potentially one day be used to map neural activity in the human brain.

“This is a demonstration, a prototype probe. But the promise is that we could use it to measure the activity state of the electrical system in an organism that has not been genetically compromised,” says senior author Jon Sack, an assistant professor in the departments of Physiology and Membrane Biology at UC-Davis. Sack is a faculty member in the MBL Neurobiology course.

Since the probe binds selectively to one of the many different kinds of ion channels, it can help scientists disentangle the function of those specific channels in neuronal signaling. This can, in turn, lead to the identification of drug targets for neurological diseases and disorders.

“We have an incredible diversity of ion channels, and even of voltage-activated ion channels. The real trouble has been determining which ones perform which roles. Which ones turn on and when in normal nervous system functioning? Which are involved in abnormal states or syndromes?” Sack says. “The dream is to be able to see what the different types of ion channels are doing and when, to understand what they contribute to physiology and pathophysiology.”

These probes respond to movement of ion channel voltage sensors, and it is particularly fulfilling to have conducted some of this work at the MBL, Sack says. The first measurements of voltage sensor movement were conducted at the MBL in the early 1970s by Clay M. Armstrong and Francisco Bezanilla (Nature 242: 459-461, 1973). Armstrong and Bezanilla used electrophysiological methods to measure the movement of voltage sensors. The spider toxin probe create an optical signal when voltage sensors move, and no electrophysiology or genetic mutation of the channels is required.

Citation:

Tilley DC, Eum KS, Fletcher-Taylor S, Austin DC, Dupré C, Patrón LA, Garcia RL, Yarov-Yarovoy V, Cohen BE, and Sack JT (2014) Chemoselective tarantula toxins report voltage activation of wild-type ion channels in live cells. PNAS doi: www.pnas.org/cgi/doi/10.1073/pnas.1406876111.

For more information, please see the UC-Davis press release.

Movie:

Recorded by Kenneth Eum, Lillian Patrón, and Christophe Dupré in the MBL Neurobiology course


The Marine Biological Laboratory (MBL) is dedicated to scientific discovery and improving the human condition through research and education in biology, biomedicine, and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

Diana Kenney | Eurek Alert!
Further information:
http://www.mbl.edu/blog/tarantula-toxin-is-used-to-report-on-electrical-activity-in-live-cells-2/

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>