Lesson 12 of 18
Objective: SWBAT explain steps of neurotransmission that lead to neurotransmitter release.
To engage students in the lesson, I show How do we smell, a TEDEd video, which attempts to answer the question of "How do we smell?"
The objective of this video is to build interest and a sense of inquiry in students. This video is directly related to the lesson's objective, since smelling involves neurotransmission between receptor neurons and brain. (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.)
As students watch, they also are accountable to answer the following questions:
1. What is true about your sense of smell?
- It's the first sense you use when you're born
- One out of every fifty of your genes is dedicated to it
- An adult can distinguish about 10,000 different smells
- All of the above
2. Approximately 95% of your nasal cavity is used simply to ________.
- Collect enough oxygen to supply the bloodstream
- Filter the air before it hits your lungs
- Detect pheromones that may lead to activities that further our species
- Provide a place for the production of mucus
3. Olfactory receptor cells are like ________.
- Taste buds
4. A dog's olfactory epithelium is ________ times larger than a human's.
5. Olfactory neurons are the only neurons that are replaced on a regular basis.
- True, every 4 to 8 weeks
- False, all our neurons are replaced regularly
6. Many people who can't smell anything also can't ________.
- See very well
- Taste the way the rest of us do
- Process the sense of touch
- Hear much
Note to Teacher: Interesting fact to point out - olfactory receptor nerves are replaced unlike other neurons that are irreplaceable. We have been taught that we only have the neurons that we are born with, but this is an exception to the rule.
Lesson Context - This lesson comes after Introduction to Neurotransmission lesson where students reviewed neuron structure and function.
In this section of lesson, students model neurotransmission through the following kinesthetic activity. (SP2- Developing and Using Models - Develop a model to describe unobservable mechanisms.)
Neurotransmission Dance Party
- Go through slides 13-19 on “Neurons and Neurotransmission” to both review and teach information about several common neurotransmitters taking notes to use in a later activity.
- These slides review the various steps involved in neurotransmission:
- Resting state of neuron (Na ions outside of cell body, K ions on inside).
- Activation (depolarization) of neuron (Na ions rush in to cell body, K ions rush out of cell body)
- Traveling of action potential down axon.
- Release of neurotransmitters once action potential reaches axon terminal into synaptic gap.
3. Follow the directions and diagram below.
Materials: tennis balls (or other objects to throw), 2 buckets, duct tape, and music
Note to Teacher: Depending on size of room you may want to complete this activity outdoors.
In this section of the lesson students explore neurotoxins. Neurotoxins are poisons released by animals and plants that attack the nervous system. Neurotoxins work by altering synapses as a results affecting neurotransmitter release for various functions.
Students complete an interactive module Toxins and Synapses! from BrainU (University of Minnesota) to learn about neurotoxins.
After completing module students visit a University of Washington website, Neurotoxins, that lists various animals' neurotoxins. (This site requires Java to run.)
Students are required to write down the name of five neurotoxins, including its source and its neural action.
In this section of lesson students complete a Multi flow map.
This map is used to help show relationships between events. It allows you to state causes of an event before (or to the left) of a stated event and effect after (or to the right) of the stated event.This map can also be used as a “partial” multi-flow map. This allows you to just focus on the causes OR effects of an event. For example, you could just focus on the outcomes of a flood or drought. Maybe you just want to focus of the events that caused a situation, like why two people became friend.
How to create this map:
1. In the center of your paper write the event that you are thinking about. Then draw a box around it.
2. To identify something that caused the event to happen, write it to the left of the box. After writing, put a box around the statement and draw an arrow pointing towards the center.
3. To identify something that was an effect of the event, write it to the right of the center box. After writing, put a box around the statement and draw an arrow from the center to the right.
An example of a flow map dealing with bad breath is found below. I model the use of a multi flow map by choosing a simple cause and effect relationship, for example bad breath.
For this multi-flow map the topic is neurotransmission. Students are required to use the following key vocabulary words in their flow map. The objective of this map is to assess student understanding that a cause (depolarization) of neuron is required to have (effect) neurotransmitter release. (CCC - Cause and Effect - Cause and effect relationships may be used to predict phenomena in natural systems.)
- Na ions
- K ions
- Action potential