1. COGNITIVE SCIENCE 17 The Electric Brain Part 2 Jaime A. Pineda, Ph.D.

2. Phases of the Action Potential Firing threshold is the point at which the number of activated Na+ channels > inactivated Na+ channels Absolute refractory period Relative refractory period

3. Nodes of Ranvier Initial segment

5. Advantages of myelination Reduces number of ion channels Reduces number of Na+ / K+ pump Increases speed of conduction Reduces energy needs

7. Saltatory Conduction

8. Exocytosis

10. RECEPTORS Ionotropic Metabotropic

11. Ionotropic Metabotropic Form a channel

12. Ionotropic Receptor agonist

13. antagonist

15. Metabotropic Receptor

16. (leads to opening of channel)

17. Upregulation Downregulation Changes to Postsynaptic Receptor Density as a Function of the Amount of Neurotransmitter Released