1. Synaptic Nerve Transmission Getting the Message From Here to There

2. Nerve “Junctions” Synapse:Junction between nerve-nerve or nerve-muscle Synapse = “Gap”: How does the signal from the excited neuron get across the gap? TELL ME WHAT YOU KNOW

3. Summary of Terms: Presynaptic Terminal: Axon – “terminal boutons” Postsynaptic Membrane: Dendrite, neuron cell body, muscle cell, or even another axon Synaptic Cleft: The Gap

4. More Terms: Synaptic Vesicles: Contain chemical signal Neurotransmitter Post Synaptic Receptors: Associated with ion channels Opening or closing channels when bound to neurotransmitter

5. Sequence of Synaptic Transmission: 1. An Action Potential arrives at the Presynaptic Terminal 2. The voltage causes the Synaptic Vesicles to release neurotransmitter into the synaptic cleft. 3. Neurotransmitter binds with Postsynaptic receptors

6. And Next… Postsynaptic membrane channels open: Open Na+ Channels causes an action potential in the “downstream” cell Open K+ Channels causes hyperpolarization which means the cell is less able to be excited!

7. What Next? The Fate of Leftover Neurotransmitters 1. Why the bother? 2. Enzyme degradation 3. Active Transport “recycling” 4. Neurotoxin Target!

8. Neurotransmitters: Norepinepherine Acetylcholine Serotonin Dopamine GABA Glutamate…The list is growing!

9. Solve This Sherlock: What would happen to someone who is given an Monoamine oxidase inhibitor?

10. HINT: MAO Inhibitors block the enzymes that breakdown norepinepherine and serotonin…. Norepi and serotonin signals are lower than normal in persons suffering from depression

11. Assignment: Read: 8:201-216 The Synapse The Central Nervous System Answer: How do Cocaine and amphetamines affect the nervous system?