Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Sensor gives valuable data for neurological diseases and treatments

Abstract:
A new biosensor developed at Purdue University can measure whether neurons are performing correctly when communicating with each other, giving researchers a tool to test the effectiveness of new epilepsy or seizure treatments.

Sensor gives valuable data for neurological diseases and treatments

West Lafayette, IN | Posted on April 20th, 2010

Marshall Porterfield, an associate professor of agricultural and biological engineering and biomedical engineering, postdoctoral researcher Eric McLamore, and graduate student Subhashree Mohanty developed the self-referencing glutamate biosensor to measure real-time glutamate flux of neural cells in a living organism. The nanosensor not only measures glutamate around neural cells, it can tell how those cells are releasing or taking up glutamate, a key to those cells' health and activity.

"Before we did this, people were only getting at glutamate indirectly or through huge, invasive probes," said Porterfield, whose research was published in the early online version of the Journal of Neuroscience Methods. "With this sensor, we can 'listen' to glutamate signaling from the cells."

The firing of neurons is involved in every action or movement in a human body. Neurons work electrically, but ultimately communicate with each other through chemical neurotransmitters such as glutamate. One neuron will release glutamate to convey information to the next neuron's cell receptors.

Once the message is delivered, neurons are supposed to reabsorb or clear out the glutamate signal. It is believed that when neurons release too much or too little glutamate and are not able to clear it properly, people are prone to neurological diseases.


ABSTRACT

A Self-Referencing Glutamate Biosensor for Measuring Real-Time Neuronal Glutamate Flux

E.S. McLamore, S. Mohanty, J. Shi, J. Claussen, J.L. Rickus, S.S. Jedlicka, D.M. Porterfield

Quantification of neurotransmitter transport dynamics is hindered by a lack of sufficient tools to directly monitor bioactive flux under physiological conditions. Traditional techniques for studying neurotransmitter release/uptake require inferences from non-selective electrical recordings, are invasive/destructive, and/or suffer from poor temporal resolution. Recent advances in electrochemical biosensors have enhanced in vitro and in vivo detection of neurotransmitter concentration under physiological/pathophysiological conditions. The use of enzymatic biosensors with performance enhancing materials (e.g., carbon nanotubes) has been a major focus for many of these advances. However, these techniques are not used as mainstream neuroscience research tools, due to relatively low sensitivity, excessive drift/noise, low signal-to-noise ratio, and inability to quantify rapid neurochemical kinetics during synaptic transmission. A sensing technique known as self-referencing overcomes many of these problems, and allows non-invasive quantification of biophysical transport. This work presents a self-referencing CNT modified glutamate oxidase biosensor for monitoring glutamate flux near neural/neuronal cells. Concentration of basal glutamate was similar to other in vivo and in vitro measurements. The biosensor was used in self-referencing (oscillating) mode to measure net glutamate flux near neural cells during electrical stimulation. Prior to stimulation, the average in?ux was 33.9 � 6.4 fmol cm-2s-1). Glutamate efflux took place immediately following stimulation, and was always followed by uptake in the 50-150 fmol cm-2s-1 range. Uptake was inhibited using threo--benzyloxyaspartate, and average surface flux in replicate cells (1.1 � 7.4 fmol cm-2s-1) was significantly lower than uninhibited cells. The technique is extremely valuable for studying neuropathological conditions related to neurotransmission under dynamic physiological conditions.


Jenna Rickus, an associate professor of agricultural and biological engineering and biomedical engineering who oversaw the study's neurological aspects, said researchers need more information about how neurons work to create more effective treatments for neurological disorders.

"Understanding neurotransmitter dynamics has implications for almost all normal and pathological brain function," Rickus said. "The reason we don't have good information is because we haven't had a good measurement tool before."

Porterfield and McLamore's sensor exploits conductive carbon nanotubes and is only 2 micrometers in diameter, or about 50 times smaller than the diameter of a human hair. They also use an enzyme, called glutamate oxidase, on the end of the probe that reacts with glutamate to create hydrogen peroxide. The carbon nanotubes enhance the conductivity of the hydrogen peroxide, and a computer can calculate the movement of glutamate relative to the cell surface.

The sensor oscillates and samples the concentration activities of glutamate at various positions relative to the neurons in culture. Those measurements at different distances can tell researchers whether the glutamate is flowing back toward the neurons or dissipating in many directions.

Current sensor technology allows for sensing in vitro, but those probes are large and invasive, Porterfield said, and they don't measure the movement of the chemicals.

McLamore said the sensor also is valuable because it is able to hone in on only glutamate using just one probe and custom software that filters out variations in the signals that are read, which removes signal noise due to other compounds.

"There are many compounds present near the neurons which can potentially create noise, but this sensor should be selective for one compound. We filter out all of the background noise," McLamore said. "It's the same thing modern hearing aids do. They're filtering out ambient noises, and that's the same thing you get when you oscillate a biosensor."

The sensor also could be adapted to measure other chemicals by changing the enzyme used on its tip.

Rickus said the sensor's versatility would be valuable for understanding the effects of therapies for epilepsy, Parkinson's disease, damage caused by chemotherapy, memory loss and many other conditions. The sensor will give valuable data on how damaged neurons function and how drugs or therapies affect those cells.

Porterfield said the next step is to make small improvements to the sensor and adapt it to use other enzymes. The Office of Naval Research funded the research.

####

For more information, please click here

Contacts:
Writer: Brian Wallheimer,
765-496-2050,

Sources: Marshall Porterfield,
765-494-1190,

Jenna Rickus, 765-494-1197,

Eric McLamore, 806-239-9556,

Ag Communications: (765) 494-8415;
Steve Leer,

Copyright © Purdue University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

National Space Society Congratulates SpaceX on the Falcon 9's Return to Flight January 19th, 2017

Eric Berger Wins the National Space Society's 2017 Space Pioneer Award for Mass Media January 19th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Possible Futures

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

National Space Society Congratulates SpaceX on the Falcon 9's Return to Flight January 19th, 2017

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

Strength of hair inspires new materials for body armor January 18th, 2017

Academic/Education

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Enterprise In Space Partners with Sketchfab and 3D Hubs for NewSpace Education October 13th, 2016

New Agricultural Research Center Debuts at UCF October 12th, 2016

Nanotubes/Buckyballs/Fullerenes

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Nano-chimneys can cool circuits: Rice University scientists calculate tweaks to graphene would form phonon-friendly cones January 4th, 2017

WPI researchers build liquid biopsy chip that detects metastatic cancer cells in blood December 15th, 2016

Infrared instrumentation leader secures exclusive use of Vantablack coating December 5th, 2016

Nanomedicine

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

Keystone Nano Announces FDA Approval Of Investigational New Drug Application For Ceramide NanoLiposome For The Improved Treatment Of Cancer January 10th, 2017

Sensors

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

Researchers create practical and versatile microscopic optomechanical device: Trapping light and mechanical waves within a tiny bullseye, design could enable more sensitive motion detection January 11th, 2017

STMicroelectronics Peps Up Booming Social-Fitness Scene with Smart Motion Sensors for Better Accuracy, Longer Battery Life, and Faster Time to Market January 2nd, 2017

Announcements

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

National Space Society Congratulates SpaceX on the Falcon 9's Return to Flight January 19th, 2017

Eric Berger Wins the National Space Society's 2017 Space Pioneer Award for Mass Media January 19th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Nanobiotechnology

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project