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Neurobiology And Drug Discovery Project On C. elegans (worm) Models Of Movement Disorders

RESEARCH TEAM*

Dr. Bhagwati Gupta (Biology)
Dr. Ravi Selvaganapathy (Mechanical Engineering)
Dr. Ram Mishra (Psychiatry and Neuroscience)

* (click on names to visit lab websites)

More information and movies about papers published by our group

 

A normal worm moving freely inside the channel This worm is unable to move because of defects in neurons that sense the electric field This worm has severely defective muscles and as a result barely moves in the channel
EF (electric field) '+' and '-' refere to directions of the current. The EF values are shown in volts per centimeter (v/cm)


Details of Lab Chip paper

Electrotaxis of Caenorhabditis elegans in a microfluidic environment
Pouya Rezai, Asad Siddiqui, Ponnambalam Ravi Selvaganapathy and Bhagwati P. Gupta
Department of Biology and Department of Mechanical Engineering
McMaster University, Hamilton, ON, Canada L8S 4K1.

Lab Chip (2010), DOI: 10.1039/b917486a

Abstract

The nematode (worm) Caenorhabditis elegans is one of the most widely studied organisms for biomedical research. Currently, C. elegans assays are performed either on petri dishes, 96-well plates or using pneumatically controlled microfluidic devices. In this work, we demonstrate that the electric field can be used as a powerful stimulus to control movement of worms in a microfluidic environment. We found that this response (termed electrotaxis) is directional, fully penetrant and highly sensitive. The characterization of electrotaxis revealed that it is mediated by neuronal activity that varies with the age and size of animals. Although the speed of swimming is unaffected by changes in the electric field strength and direction, our results show that each developmental stage responds to a specific range of electric field with a specific speed. Finally, we provide evidence that the exposure to the electric field has no discernible effect on the ability of animals to survive and reproduce. Our method has potential in precisely controlling, directing, and transporting worms in an efficient and automated manner. This opens up significant possibilities for high-throughput screening of C. elegans for drug discovery and other applications.


Details of Applied Physics Letters paper

Behavior of Caenorhabditis elegans in alternating electric field and its application to their localization and control
Pouya Rezai, Asad Siddiqui, Ponnambalam Ravi Selvaganapathy and Bhagwati P. Gupta
Department of Mechanical Engineering and Department of Biology
McMaster University, Hamilton, ON, Canada L8S 4K1.

Appl. Phys. Lett. 96, 153702 (2010); doi:10.1063/1.3383223

Abstract

Caenorhabditis elegans is an attractive model organism because of its genetic similarity to humans and the ease of its manipulation in the laboratory. Recently, it was shown that a direct current electric field inside microfluidic channel induces directed movement that is highly sensitive, reliable, and benign. In this letter, we describe the worm’s movement response to alternating electric fields in a similar channel setup. We demonstrate that the 1 Hz and higher frequency of alternating current field can effectively localize worms in the channel. This discovery could potentially help design microfluidic devices for high throughput automated analysis of worms.


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