में मांग पर हरकत को उत्पन्न करने के लिए एक अर्द्ध स्वचालित माइक्रो विद्युत fluidic विधि<em> Caenorhabditis एलिगेंस</em> वर्णित है. इस विधि microfluidic चैनलों के अंदर हल्के बिजली क्षेत्र ("electrotaxis") का जवाब देने के कीड़े की neurophysiologic घटना पर आधारित है. Microfluidic electrotaxis न्यूरोनल स्वास्थ्य को प्रभावित करने वाले कारकों के लिए स्क्रीन करने के लिए एक तेजी से, संवेदनशील, कम लागत, और स्केलेबल तकनीक के रूप में कार्य करता है.
The nematode Caenorhabditis elegans is a versatile model organism for biomedical research because of its conservation of disease-related genes and pathways as well as its ease of cultivation. Several C. elegans disease models have been reported, including neurodegenerative disorders such as Parkinson’s disease (PD), which involves the degeneration of dopaminergic (DA) neurons 1. Both transgenes and neurotoxic chemicals have been used to induce DA neurodegeneration and consequent movement defects in worms, allowing for investigations into the basis of neurodegeneration and screens for neuroprotective genes and compounds 2,3.
Screens in lower eukaryotes like C. elegans provide an efficient and economical means to identify compounds and genes affecting neuronal signaling. Conventional screens are typically performed manually and scored by visual inspection; consequently, they are time-consuming and prone to human errors. Additionally, most focus on cellular level analysis while ignoring locomotion, which is an especially important parameter for movement disorders.
We have developed a novel microfluidic screening system (Figure 1) that controls and quantifies C. elegans‘ locomotion using electric field stimuli inside microchannels. We have shown that a Direct Current (DC) field can robustly induce on-demand locomotion towards the cathode (“electrotaxis”) 4. Reversing the field’s polarity causes the worm to quickly reverse its direction as well. We have also shown that defects in dopaminergic and other sensory neurons alter the swimming response 5. Therefore, abnormalities in neuronal signaling can be determined using locomotion as a read-out. The movement response can be accurately quantified using a range of parameters such as swimming speed, body bending frequency and reversal time.
Our work has revealed that the electrotactic response varies with age. Specifically, young adults respond to a lower range of electric fields and move faster compared to larvae 4. These findings led us to design a new microfluidic device to passively sort worms by age and phenotype 6.
We have also tested the response of worms to pulsed DC and Alternating Current (AC) electric fields. Pulsed DC fields of various duty cycles effectively generated electrotaxis in both C. elegans and its cousin C. briggsae 7. In another experiment, symmetrical AC fields with frequencies ranging from 1 Hz to 3 KHz immobilized worms inside the channel 8.
Implementation of the electric field in a microfluidic environment enables rapid and automated execution of the electrotaxis assay. This approach promises to facilitate high-throughput genetic and chemical screens for factors affecting neuronal function and viability.
पहले चुआंग और उनके सहयोगियों 11,12 के dielectrophoretic हेरफेर काम पर Gabel और उनके सहयोगियों और इमारत से वर्णित व्यवहार घटना का लाभ उठाते हुए, हमारे microfluidic आधारित electrotaxis परख आंदोलन के रूप में उपयोग करते हुए कीड़े में neuron…
The authors have nothing to disclose.
लेखकों को वित्तीय सहायता के लिए अपने प्रारंभिक शोधकर्ताओं पुरस्कार कार्यक्रम के माध्यम से प्राकृतिक विज्ञान और कनाडा के इंजीनियरिंग रिसर्च काउंसिल, कनाडा अनुसंधान अध्यक्षों कार्यक्रम, स्वास्थ्य अनुसंधान संस्थान कनाडा, और अनुसंधान और नवाचार के ओंटारियो मंत्रालय को धन्यवाद देना चाहूंगा.
Name of the reagent | Company | Catalogue number | Comments (optional) |
Acetone | CALEDON Labs | 1200-1-30 | |
Methanol | CALEDON Labs | 6700-1-30 | |
Isopropanol | CALEDON Labs | 8600-1-40 | |
SU-8 | Microchem Corp. | Y131273 | SU-8 100 |
SU-8 Developer | Microchem Corp. | Y020100 | |
92×16 mm Petri dish | Sarstedt | 82.1473.001 | |
Sylgard 184 Silicone Elastomer Kit | Dow Corning | Contains elastomer base and curing agent | |
Function generator | Tektronix Inc. | Model AFG3022B | |
Amplifier | Trek Inc. | Model 2210-CE | |
Syringe pump | Harvard Apparatus | 70-4506 | Model 11 ELITE |
Hot plate | Fisher Scientific | 11675916Q | Model HP131725Q |