Lets Talk - Introduction to Neurotransmission

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Objective

SWBAT to sequence steps in neurotransmission.

Big Idea

Students explore neurotransmission through a variety of activities including a kinesthetic model.

Engage

10 minutes

I start class by showing students the video below from TedEd titled The Cockroach Beatbox. This video introduces students to how the brain receives and send signals through neurotransmission.

As students watch the video, they answer the following questions:

1.  Your brain has about 100 billion of these

a)    Neurotransmitter molecules

b)   Electrical impulses per hour

c)    Neurons

d)   Don’t know, but I’m pretty sure I blew through three or four million of ‘em while thinking about this question.

  

2.  According to Gage, we have a much easier time understanding and explaining organs like the heart and lungs than we do with the brain. Why is that?

 

3.  What is an action potential or "spike"?

a)    A pulse of electricity sent down the axon of excitable cells like neurons.

b)   The infant brain’s ability to generate new neurons from special, undifferentiated cells in the brain stem.

c)    The relative speed of various neurotransmitters moving across synapses.

d)   The ability to transfer specific functions from an injured part of the brain to an adjacent, healthy area.

  

4.  For some people, the use of live animals (even cockroaches) in experiments like Gage’s seems cruel. What evidence does Gage offer that this is not the case? What’s your reaction?

  

5.  Gage demonstrates that dropping a cockroach into ice water causes it to:

a)    Die

b)   Become temporarily anesthetized (falls asleep or "Chillaxes")

c)    Assume the fetal position

d)   C, then A

 

6.  Action Potentials or “Spikes” are used by the nervous system to send:

a)    Information from your senses to the brain.

b)   Information within your brain.

c)    Information from your brain to your muscles.

d)   All of the above.

 

7.  How did Gage use his iPhone during his experiment?

a)    To share his data with an amateur-scientist wiki community.

b)   For a quick Angry Birds break while waiting for the roach anesthetic to kick in.

c)    To film a four-inch giant hissing cockroach and post it to his Facebook page.

d)   As a source of electrical current.

 

At the conclusion of video I go over the questions above along with any questions that students might have after watching video.

Explore

15 minutes

In this section of lesson students explore neurotransmission through an interactive module courtesy of brainu.org. (MS-LS1-8. Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories.)  

In this module students are able to explore the following topics:  

  1. Review neuron structure
  2. Action potentials
  3. Neurotransmitters 
  4. Synaptic cleft
  5. Active potential threshold 
  6. Mechanism behind making stronger connections and loosing connections.(CCC - Cause and Effect - Cause and effect relationships may be used to predict phenomena in natural systems.) 
  7. Relationship between individual circuit and information it contains.

To guide them to learn about these topics, students complete Synapses Change as they complete the module.

Explain

15 minutes

In this section of lesson I reinforce what they learned in the module by going over The Zombie Autopsies, a presentation from PBS.org.

Directions:

1)  Show them the first 6 slides of the Neurons and Neurotransmission presentation (it is a .pdf but it can be used like a power point) reading over and discussing each slide.

2)  Put students into small groups and give them their copy of Giant Neuron Puzzle.  Have students put the puzzle together (tape or staples work) and then label their neuron with the words on slide 6 and using the image to help them. (MS-LS1-2. Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.) 

3)  Return to the Neurons and Neurotransmission and go over slides 7-13, which explain the process of neurotransmission.  On slide 13 there are two very good short video clips on the full process.

In terms of taking notes, students are only required to take notes on the slide that discusses the movement of sodium and potassium ions to initiate an action potential (depolarization).  This information will be important for our next lesson, when we will model depolarization. (CCC - Cause and Effect - Cause and effect relationships may be used to predict phenomena in natural systems.) 

Elaborate

15 minutes

Now students model neurotransmission by using the Giant Neurons they created in the previous section of the lesson to play a game of telephone. (SP2 - Developing and Using Models - Develop and use a model to describe phenomena.) 

Directions:

Play Telephone with the Giant Neurons
  1. Have students standup in their groups with their Giant Neurons and have the entire class form a straight line with neurons almost touching.  They must line their neurons up in the same direction from dendrites (right) to terminal buttons (left) throughout the entire straight line.
  2. Check to make sure students are lined up correctly and that there is SPACE between each neuron (synaptic gap).
  3. Explain to the class that you are now going to attempt neurotransmission and you will do this by playing the game of telephone.

Here are the rules:

  • The teacher picks the phrase - make it fun!
  • You may only say the phrase to the person next to you once- no repeating!
  • The last person to go will whisper the answer to the teacher and the teacher will announce the phrase to the class.

A few suggestions on this exercise- You want to have neurotransmission take place as quickly as possible so encourage the kids to speed up. The kids will most likely botch up the phrase, but try to explain that if their neurons in their brain did that they would have a pretty terrible life. Play several rounds and have fun.


Evaluate

5 minutes

Now it is time for students to complete a Flow Map for neurotransmission.

They are required to use the following list of vocabulary words in their flow map.

  1. Neurotransmitters
  2. Dendrites
  3. Synapse
  4. Soma
  5. Axon
  6. Terminal
  7. Action Potential

To introduce students to how the use of a flow map, I model it by creating one for an everyday experience for most people, making a peanut butter jelly sandwich.

 An example of one is found below: