I’m always getting crazy ideas. Sometimes they’re crazy good ideas, sometimes just plain crazy.
This week’s crazy idea came out of my frustration with teaching cell membrane potentials. It’s a very difficult… no, that’s too negative…challenging concept for students. A series of pictures in a textbook is hard to visualize. A video or animation is better, but students still have a hard time internalizing the concepts of resting membrane potentials, local potentials and action potentials.
My crazy idea was to borrow a page from Miss Silvers play book. Miss Silvers was my kids’ science teacher at Science Hill Middle School (yes, our town is really named Science Hill). She retired a few years ago and was one of the best teachers I have ever known. The students all dreaded taking her because she was so demanding, but my kids still remember lessons they learned in her class over eight years ago. (I’m happy if my students remember lessons from the previous semester.) My daughter says that the science she learned in Miss Silver’s classes carried her all the way through high school and part way through her college science classes. My daughter can still vividly remember lessons in Miss Silver’s classroom because they were so active. Miss Silver’s always had them up and moving, acting out processes, testing themselves against each other, and learning by doing.
I was worried at first that college students would find these kinds of activities too hokey. They were adults, not kids! I shouldn’t have been surprised to find that most students like fun, even if it is hokey. A few semesters ago I started putting smiley faces on assignments and quizzes with perfect grades. Hokey, I know. Kindergarten stuff. Students LOVE them! God forbid that I should forget to put a smiley face on a paper. Now I announce “Smiley Face!” when I hand back those papers and those students cheer and beam. Hokey is obviously not a barrier.
So I decided I would disrupt the daily class routine and instead of having our usual clicker question session we would ‘Be an Action Potential’! We moved the desks into the shape of a neuron (as best we could). I handed out signs to the students identifying them as ions, voltage gated ion channels, ligand gated ion channels, Na+/K+ pumps, acetylcholine (2 students, of course), acetylcholinesterase, and all the other components of neurons.
We started by building the cell membrane with ion channels and Na+/K+ pumps. The pump/students established the resting membrane potential by moving student ions between the desks to be on the correct side of the membrane. Then we created a local potential by opening ligand gates in the dendrites and letting the students labeled ‘Na+ ion’ into the neuron. As we discussed the movement of ions during an action potential, the students moved around and became the action potential. We ended with the release of acetylcholine into the synaptic cleft and then the removal of acetylcholine by acetylcholinesterase.
The students were certainly attentive during the activity. It’s hard to be distracted by a text message when you might have to repolarize the membrane. With any luck, ‘Being an Action Potential’ will be as memorable as one of Miss Silver’s classes. Or maybe I’m just crazy.