Lesson Highlighting the Neuron

Learning Objectives

After this lesson, students should be able to:

• Use a diagram to describe the function of the neuron.
• Apply their understanding of the neuron to examine biomedical applications.
• Define ways in which current research may support patients with nerve-related injuries using their understanding of the neuron.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Worksheets and Attachments

Pre-Req Knowledge

A familiarity with cell structure and function, in addition to an understanding of the nervous system, is beneficial to the implementation of this lesson.

Introduction/Motivation

(Note: Before the lesson, make copies of the Robotic Arm Article, Robotic Arm Annotation Guide and Discussion Questions, and Lesson Review Activity: Neuron Naming, one each per student. Prior to the start of the lesson, consider how to best form the class into groups of two students each. This lesson also uses computer projection, which you may want to set up in advance. Additionally, students each need a piece of paper.)

Before we begin today's lesson, let's brainstorm the ways in which engineers and neuroscientists work together to support the nervous system, especially injured nervous systems. Please fold a piece of paper in half vertically. On one half of the paper, write the word: Now. On the other half of the paper, write: 15-20 Years from Now.

On the Now side of your paper, list or draw the ways that neuroscientists and engineers work together to support the nervous system, especially for people who have had injuries to their nervous systems. On the 15-20 Years from Now side of your paper, complete the same task, only this time predict what neuroscientists and engineers might be doing 15-20 years from now to support the nervous system (refer to Now & Future – Student Example). (Give students 3-5 minutes to list their thoughts on paper.)

Okay, let's share our ideas. First, let's discuss what you think is happening Now. When I call your name, please tell the class what you wrote on your paper. (Listen to student ideas.) Those are great ideas! Now let's hear what you think will happen 15-20 Years from Now. When I call your name, please share with the class what you wrote on the other side of your paper.

In a few moments, I'd like you to read an article about an individual, named Jan, who used her thoughts to control a robotic arm. The article will help you recognize the importance of engineers in the medical field and how their technology brought new life to Jan by increasing her daily experiences that are natural occurrences for most people.

Before you read, let's review some new vocabulary. (Show students the list of words on slide 2 of the Neuron PowerPoint® Presentation.) When you come to these words, use this slide to help you understand their meanings. The first term is spinocerebellar degeneration. This is the name of Jan's disease, which caused her to be paralyzed from the neck down. She is paralyzed because her nervous system and muscular system are unable to communicate with one another.

The next term is geiger counter click. This phrase is used as an analogy—a comparison—in the article; you need to understand the analogy to understand why the term is used. A Geiger counter is a device that detects radiation, and when radiation is present it makes a clicking noise.

Lastly, although many of you may know someone who has been affected by a stroke, I want you to know that they are caused by a lack of oxygen in the brain. This lack of oxygen kills neurons, which causes that part of the brain to stop functioning.

(While reading the paragraph below, hand out individual copies of the article, annotation guide and discussion questions. Also at this point, inform students who will be their working partners for parts of this lesson.)

Once you have received your copy of the article and annotation guide, take notes as you read it to yourself. After reading, silently answer the discussion questions that follow. You will have 15 minutes to read and answer questions. If you have time, complete the bonus question.

(Crculate the classroom to monitor students and support those who have questions. Ensure students are working alone on this part of the lesson.)

Next, please take one minute to silently answer the bonus question, if you have not done so already. If you have already answered the bonus question, review your response and check for spelling, punctuation and grammar errors.

(Pause for two minutes.)

Now that you have had time to read the article and reflect on it by answering the questions, share your thoughts with your partner. Please turn to your partner and, one at a time, share your answers to Question 4 and the bonus question. Select which partner will go first, and then begin.

(Circulate around the room to listen in on student responses. Give students 3-5 minutes to discuss.)

As I walked around the classroom, I heard that (insert student responses, such as, "Many of you felt that this technology is worthwhile and that it could be very important for future stroke victims or paralyzed individuals." or "Some of you thought that this technology might allow someone else to control your thoughts, and that that is a scary idea.") Now that you know about Jan's story, let's look at a picture of her eating the chocolate bar (show students a picture of Jan eating a chocolate bar on slide 3). With your partner, examine the photograph and then discuss whether any restrictions exist for users of this technology, or any other issues that might prohibit others from trying this new technology.

(Circulate around the room to listen in on student responses. Give students 3-5 minutes to discuss.)

As you were discussing, I heard that you think some restrictions might exist, such as (insert student responses, such as, "Those cords coming out of Jan's head might stop her from moving around a lot.")

As you read, you hopefully realized that what you think will happen 15-20 years from now, is actually happening now! Jan explains that she was particularly excited about the use of a robotic arm because she was finally able to eat a chocolate bar all by herself, after many years of not being able to. As you read, did you wonder why Jan was so excited to eat a chocolate bar by herself? Or why she would even need a robotic arm to do so? The article should have answered these questions for you.

Today, engineers are considering new ways to activate cells in the brain, called neurons, so that people, or other animals, would not be as restricted. Many engineers use microscopic LED lights to activate neurons. These lights send an electrical signal through the neurons, which causes an animal to behave in a certain way. Yet, in order for engineers to start developing these new devices, they first need a solid understanding of how neurons work to send messages. As I read aloud about our nervous system, pretend that you are an engineer who is researching the information s/he needs to better understand how it is possible for neurons to be activated by lights.

Our nervous system is comprised of different organs, tissues and cells. Remember that an organ system is made of organs, and the organs are made of tissue. Tissue is composed of even smaller parts, called cells. The nervous system is composed of a specialized cell, called the neuron. (Show students a picture of a neuron on slide 4.) With your partner, look at the image of the neuron and discuss with each other how the structure of this specialized cell looks (pause for partner discussion). Taking turns, let's share our ideas with the whole class. Raise your hand and share your partner's response. (Expected comments: The neuron has branches. It has a small round piece at the bottom with more branches, called axons, coming off it.)

Now that you have seen what a real neuron looks like, let's look at a diagram to help us understand the function, or purpose, of the neuron within an organism's body. (Show students the neuron diagram on slide 5.) As you can see at the top of the diagram, the function of a neuron is to send messages between the brain and other parts of the body. The neuron also sends messages from the body to the brain.

For example, have you ever accidentally touched something with your hand that was very hot? If so, your body had to instantly respond to that hot surface to quickly remove your hand so that it would not be severely burned. The neurons within your body instantaneously responded to that message.

Let's zoom in on each part of the neuron to understand how they all work together to carry messages. First, the dendrites, which surround the cell body, receive a message. (Point to dendrites.) The message is then transferred through the axon, which looks like a string. (Point to axon.) The message then reaches the branches of the axon and travels through each string-like structure to the end, called the axon terminal. (Point to axon terminals.)

Once it reaches the axon terminal, the message travels through the synapse, which is a microscopic gap between two neurons. (Show the image of a synapse on slide 6.) Looking at the image on the screen, we see that the axons of one neuron are very close to the dendrites of another neuron. This allows messages to travel from one neuron to the next throughout an organism's entire body. The message travels through the synapse through electrochemical means. (Remind students that "electro" comes from the electrical charges within neurons, and "chemical" comes from chemical processes created by neurons.)

To review, you and your partner are going to do a fun activity on neurons (Associated activity Building the Neuron). Each pair will receive a plastic bag of an image of a neuron and strips of paper with phrases and words. Your task is to label the different structures of the neuron, and to tell how a neuron transports messages.

(Hand out the Lesson Review Activity: Neuron Naming. Circulate the classroom to check for placement of words and phrases. If students show an understanding of the function and structures of the neuron, proceed to the Lesson Closure and Assessment sections. If not, re-review the information presented in this section.)

Lesson Background and Concepts for Teachers

Who is Jan Scheuermann?

Jan Scheuermann suffers from spinocerebellar degeneration, which has left her paralyzed from the neck down. She uses her thoughts to control a robotic arm using a brain computer interface, which enables neurons to communicate with a device outside the body. Previous research ed to surgery in which sensors were implanted on Jan's brain. These sensors pick up on the electrical impulses sent from Jan's neurons and, using computer connectors, these impulses are translated by the computer and sent to the robotic arm. Jan has practiced extensively to feed herself the chocolate bar identified in the article students read, but the research conducted has lead to new ideas and possibilities for brain computer interfaces. See the Additional Multimedia Support section for resources to further understand the research.

How Do Neurons Transmit Messages?

Although the lesson does not discuss in detail how neurons transmit messages from one to another, the term electrochemical is introduced. Through this process, the neurons are activated by electrical impulse, which simply means ions are involved. These impulses carry messages through the axon until they reach the axon terminal. Once messages reach the synapse they are converted from electrical to chemical impulses. These converted impulses are then carried by neurotransmitters from one neuron to the next. Some neurotransmitters allow ions to travel with them, allowing the activation of the next neuron.

The Role of Optogenetics

Brain computer interfaces have the ability to interpret electrical impulses from neurons and use them to control robotic arms, and other technologies have the ability to activate neurons in order to control brain activity. Optogenetics utilizes optics and genes to do so. When DNA from algae is injected into the neurons of an animal, for example, that DNA allows the neuron to respond to LED lights. When the light shines upon the neurons, the neuron is able to send an electrical impulse to other neurons, despite the fact that that neuron may not normally function. With this stimulation, the animal may carry out tasks that it may not normally have thought to do. See the Additional Multimedia Support section for a link to a video resource about optogenetics.

Associated Activities

• Building the Neuron - Using microscopes, students view rat brain tissue to draw neurons. Students then use their drawings to design models of the neuron, which are built in order to teach younger students about the significance of an organism's neurons.

Lesson Closure

Now that you have learned the parts of a neuron and how these structures support the overall function of a neuron, discuss with your partner the ways in which you, an engineering team, might use this information to make contributions to the medical field. Once you have worked together to develop your thoughts, write your response on a piece of paper. (Conclude by having students read their ideas aloud to the class.)

Vocabulary/Definitions

axon: A sting-like fiber that transmits messages away from the cell body.

axon terminal: Where messages leave the neuron.

cell body: In the neuron, contains the nucleus of the cell, but not other parts.

cortex: The outer layer of the brain.

dendrites: Receive messages from other neurons and surround the cell body.

LED light: Light-emitting diode (LED) that emits one color (wavelength).

neuron: The cell that transmits messages throughout an organism.

spinocerebellar degeneration: A disease in which the spinal cord and cerebellum degenerate.

synapse : The space between two neurons in which messages are transferred.

Assessment

Pre-Lesson Assessment

Write It Out! On a piece of paper, have students write what they believe engineers and scientists are doing to support the nervous system, especially inured nervous systems.

Lesson Embedded Assessment

Annotation Guide and Discussion Questions: Review students' answers to Question 4: "According to the author, these robotic arms are controlled by 'thoughts.' Why is the author able to use the term thoughts?"

Expect student responses to include the idea that thoughts are electrical impulses and that this electrical activity can cause an external device to move.

Post-Lesson Assessment

Lesson Review Activity: Neuron Naming: Students label the structures of a neuron and describe how they support the overall function of a neuron. Also, students predict the ways engineers might use this information to contribute to the medical field.

Additional Multimedia Support

For resources to further understand the research, see the 12-minute 60 Minutes video, "Breakthrough: Robotic Limb Moved by the Mind" at: http://www.cbsnews.com/video/watch/?id=50148119n and the University of Pittsburgh's brain computer interface research in the article titled, "Woman with Quadriplegia Feeds Herself Chocolate Using Mind-Controlled Robot Arm in Pitt/UPMC Study" at: http://www.upmc.com/media/media-kit/bci/Pages/default.aspx.

Learn more about optogenetics through a 4:50-minute video: Optogenetics: Controlling the Brain with Light, at http://video.mit.edu/watch/optogenetics-controlling-the-brain-with-light-7659/.

References

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed through the Robotics Engineering for Better Life and Sustainable Future research experience for teachers under National Science Foundation RET grant number CNS 1300794. However, these contents do not necessarily represent the policies of the NSF and you should not assume endorsement by the federal government.