nematode worm culture in dog food agar plates for behavioral analysis

Undersökning av kollektiva beteenden hos nematoder med hjälp av hundmatagar medium

Both nonscientists and scientists are fascinated with animals&#39; collective behaviors, as in flocks of birds and schools of fish. Collective behaviors have been analyzed in a broad range of fields, including physics, biology, mathematics, and robotics. In particular, active matter physics is a growing research field that focuses on systems composed of self-propelled elements, that is, dissipative systems, such as flocks of birds, schools of fish, biofilms of motile bacteria, cytoskeletons composed of active molecules, and groups of self-propelled colloids. The theory of active matter physics maintains that however complex the behaviors of individuals are, the collective motions of enormous numbers of living things are governed by a small number of simple rules. For example, the Vicsek model, a candidate for a unified description of the collective motion of self-propelled particles, predicts that short-range alignment interaction of moving objects is required to form a long-range ordered phase with eccentric fluctuation in 2D, as in herds of animals1. Top-down experimental approaches pertaining to the physics of active matter are developing rapidly. Previous experiments confirmed the formation of a long-range ordered phase in Escherichia coli2. Other recent works&#160;employed cells3,4, bacteria5, motile colloids6, or moving proteins7,8. Simple minimal models such as the Vicsek model successfully described these real phenomena. In contrast with these unicellular experimental systems, collective behaviors by animals are usually observed in the wild, as no one could hope to perform controlled experiments with 10,000 real birds or fish.
Biologists share the same interest as physicists: how individuals interact with each other and functionally behave as a group. One of the traditional research fields for analyzing individual behavior is neuroscience, in which the mechanisms underlying behavior have been examined at the neuronal and molecular levels. Many neuroscientific bottom-up approaches have been developed thus far. Top-down approaches in physics and bottom-up approaches in biology can be facilitated using model animals such as the fruit fly, the worm Caenorhabditis elegans, and the mouse9. However, there have been few findings on the large-scale collective behavior of these model animals in the laboratory10; it is still difficult to prepare genetically tractable model animals on a large scale in the laboratory. Therefore, in current research on collective behaviors in biology and physics, it has been difficult for scientists who usually do research in the laboratory to study animals&#39; collective behaviors.
In this study, we established a method for the large-scale cultivation of nematodes to study their collective behaviors. This system allows us to change environmental conditions and examine the effect of individual-level locomotion on collective behaviors using mutants10. In active matter physics, the parameters of the mathematical model can be controlled in both experiments and simulations, which enables verification of that model for identifying unified descriptions. Genetics is used to understand the neural circuit mechanism underlying collective behavior11.

Författare i fokus: Kollektiv beteendeanalys av rundmasken, Caenorhabditis elegans

Storskalig odling av nematoder för att studera deras kollektiva beteenden

We are studying the mechanism underlying collective behavior from the perspective of active metaphysics and neuroscience. In the research field of collective behavior, experimental system has been established using non-living things and at the cellular level. However, it remains still challenging to design the animal-level experimental system to study the collective behavior in the laboratory.We successfully reconstructed the collective behavior with traditionally used model animal, nematode C.elegans. This system make it possible to control the parameter with mathematical model proposed for animals'collective behavior, and studies the neuromechanism underlying collective behavior using molecular genetics.

Nematodmaskkultur i hundmatsagarplattor för beteendeanalys

Börja med att placera fyra vuxna maskar på ett nematododlingsmedium eller NGM-agarplatta sådd med E.coli OP50. Odla den första generationen maskar till svält på NGM-plattan vid en temperatur av 23 grader Celsius i sju dagar. Överför sedan små mängder hundmatsagar eller DFA-medium till mitten av en ny NGM-platta sådd med E.coli OP50.För optogenetiska experiment, häll 40 mikroliter all-trans-retinal på DFA före maskinokulering. Därefter placeras 0,5 milligram hundmat på DFA-mediet, cirka två millimeter från tallrikslocket. Undvik kontaminering genom att bestråla NGM-plattan med ultraviolett ljus i 15 minuter.Samla de utsvultna maskarna från NGM-plattorna med steriliserat vatten. Inokulera sedan de uppsamlade maskarna på DFA-mediet som finns på NGM. Föröka maskarna vid 23 grader Celsius, vilket gör att de kan klättra mot tallrikslocket under 10 till 14 dagar.Ökad luftfuktighet uppvisade större fackstorlekar i masknätverkets mönster innan de slutligen kollapsade och lämnade vilande maskkluster på lockets inre yta.

Research

JoVE Journal

Biology

Nematode Worm Culture in Dog Food Agar Plates for Behavioral Analysis

The Large-Scale Cultivation of Nematodes to Study Their Collective Behaviors

Animals exhibit dynamic collective behaviors, as observed in flocks of birds, schools of fish, and crowds of humans. The collective behaviors of animals ...

Observation of the Collective Behavior and Optogenetic Experimentation of Nematode Dauer Worms

Observation av det kollektiva beteendet och optogenetiska experiment hos nematod dauer-maskar