How Fast is a Brain?

1. How Fast is a Brain?

2. With 1 electrode, you can only tell the time of the action potential, and (sometimes) the type of neuron that generated that action potential.

3. With two electrodes, you can also measure the speed of the action potential

4. Our 2-channel SpikerBox allows you to now measure neural speed (conduction velocity)!

5. But sometimes, nerves are so active you cannot isolate individual spikes.

6. We need an organism that uses…..

7. Sparse Coding means only firing 1-2 spikes in reponse to a stimulus.

8. You can find earthworms in your backyard after a heavy rainstorm causes them to come up to the surface of the water-logged soil to breathe.

10. Place the 1st, 2nd, and ground electrode ~1-2 inches away from each other, with the ground closest to the clitellum. Anesthetize the worm in 10% ethanol for 7 minutes First. Make sure to occasionally dribble water on the earthworm to keep it moist.

11. After your electrodes are in place, tap the rear of the worm lightly with a toothpick. Recording the electrophysiological responses, you should see a delay….. This allows you to measure conduction velocity, or the speed of neural conduction.