Are you Smarter than a Worm? (Operant conditioning in C. elegans) Day 1

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Objective

Students will plan and conduct an investigation to provide evidence that feedback mechanisms that maintain homeostasis in C elegans are similar to those in humans.

Big Idea

C elegans can be used as animal models to predict human learning behaviors as there are many parallels in the neural circuitry that can be interpreted in an interchangeable fashion.

Introduction

Lesson Background & Justification:

          Operant conditioning, sometimes referred to as instrumental learning, is a method of learning that occurs through reinforcements and punishments for behavior. It encourages the subject to associate desirable or undesirable outcomes with certain behaviors. Caenorhabditis elegans is a microscopic (~1 mm) nematode that normally lives in soil. It has become one of the "model" organisms in biology as it displays similar internal metabolic activity as humans, including neurological functions such as learning and memory. As such, these organisms have been used to study operant conditioning in animals and teaches us a great deal about the neurophysiology of our brains. In this lesson, (Part 1 of 3) students set set up investigations which allow for them to collect and interpret data about these worms and their capacity to learn by association.

Prerequisite Knowledge: It is recommended that students be familiar with the structure and function of a neuron, the concept of neurotransmission, the action potential mechanism and the neurobiology of learning (covered in a previous lesson). 

Lesson Preparations:

 In the effort to prepare for this lesson, I make certain that I have the following items in place: 

a) 1 Biorad elegans Behavior Kit. (Provide investigation materials for student pairs). Use the instructor's manual for preparation planning. 

b) Student lab books.

c) Class set of safety wear (glasses, lab aprons and gloves)

Common Core and NGSS Standards:

SP4- Analyzing and interpreting data.

SP2- Developing and Using Models.

SP7- Engaging in arguments using evidence. 

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.

RST.11-12.3- Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.

Standards Rationale:

      Modeling is the process by which scientists represent ideas about the natural world to each other, and then collaboratively make changes to these representations over time in response to new evidence and understandings. It is intimately connected to other scientific processes (asking questions, communicating information, etc.) and improves students ability to recall scientific jargon through association. In the classroom, it is important that teachers engage students in modeling practices, to set the foundation of success in a lesson or instructional unit. In this lesson modeling is used in concert with other science practices in the classroom to promote students’ reasoning and understanding of core science idea presented (mechanisms that direct specific biology of memory and learning in organisms.) 

Engage

10 minutes

Section Sequence: 

a) Introduce students to C. elegans by sharing that, scientists say that there is a microscopic worm called C. elegans and that it is a great organism to study if we want to see how some learning systems work in animals. I am not sure if I agree. Tell students that you want them to watch some footage that a scientist has taken and want for them to search for any sign that learning has or is taking place. Play the following and let students guide the pausing and stopping of the video to explain their points of views. Play from 1:30-3:30.

       

 b) Post-video and after brief discussions, ask students what would the worms have to possess in order for learning to take place? Remind them of the lesson's content from the previous day and to reference their notes to develop a more informed response. All students to share their ideas. 

c) Share the following video with them to show what scientists have learned about these worms.  

     

d) Discuss if these worms are ideal for learning experiments. 

Standards Covered:

SP2- Developing and Using Models.

SP7- Engaging in arguments using evidence. 

Explore

75 minutes

Section Primer:

a) Share with students that you like to find out if these worms are capable of simple operant conditioning and play the following video to clarify the concept of operant conditioning for students:

     

b) Ask students to decide upon a measurable question for our study. Take ideas until the class decides on a great question with measurable outcomes. Record the question on the board and instruct students to record it in their lab books. 

c) Share with students that the study will require a few days to gather data and to understand the implications of their data. Specifically, this will require 1 Day for initial observations and sub-culturing (exposing worms to a fresh lawn of food source) worms while simultaneously establishing the conditioning environment, a second day to execute and collect data on the how well the worms took to associative behaviors and a third day to produce universal results that draws out and pronounces trends as well as conclusions for scientific reporting. 

d) For Day 1, dispense the  Biorad's C elegans Learning Behavior Quick Guide and provide materials (listed on page 29 of the manual) to students in pairs to complete part 1/lesson 1. Students will continue to work through step 10 of lesson 1. 

Standards Covered:

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.

RST.11-12.3- Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.

Wrapping Up!

5 minutes

Section Sequence: 

            After students have had some time to observe the worms and gather a little bit of content on them, they will take the time to record a formal hypothesis. This section proceeds as follows:

a) Instruct students to revisit their investigation question and to consider some of the things that they have learned about C. elegans today. Armed with this experience and content, instruct students to form a hypothesis and record it in their lab books. 

b) Encourage students to share out on their hypothesis and to justify their thinking to the class.

Standards Covered:

Common Core and NGSS Standards:

SP7- Engaging in arguments using evidence. 

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.