Experiment Three: Effect of Temperature on Neurons
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Transcript of Experiment Three: Effect of Temperature on Neurons
Experiment Three: Effect of Temperature on Neurons
Ion channels transport Na+ and K+ across neural membrane
Action potentials (“spikes”) are generated by sodium ion (Na+) infusion depolarizing the cell membrane and potassium ion (K+) expulsion repolarizing it.
Ion channels will not open if temperature too low
Ion channels and nerve membranes come apart if
temperature too high
Procedures: Put the cockroach in a jar of ice water
Procedures: Cut off one of roach’s legs near the body
(Put petroleum jelly on exposed wound on body and leg, return cockroach to house, leg will grow back if cockroach not full grown adult)
Procedures: Place leg on cork of SpiderBox, with a bit of leg
overhang
Procedures: Put one electrode in the femur and the other in the
coxa
Exercise 1: Cool the preparation and identify temperature at which
neural spikes go away
You can also use a cooler of dry ice
Note that active refridgerators can be very electrically noisy
though..you may want to unplug the
cold freezer
Exercise 2: Heat system and identify temperature at which all neurons discharge
Tabulate heat and cold limits for different legs of different species