2. Neuron Used for communication between body parts May be as long as a meter

3. Neuron parts Cell body (soma) Contains nucleus All info collected from dendrites Dendrite Branched extension Receives incoming signals Axon Filament-like extension carrying signal away from cell body Myelin Sheath Fatty insulating cover surrounding axon Increases speed and strength of signals

4. Now label on your diagram… Axon Dendrites soma/cell body Myelin sheath Draw an arrow showing the direction of impulse travel

5. check your understanding… What is a nerve cell called? Which part of the nerve cell RECEIVES information? Which part of the nerve cell SENDS information? What is like the insulation around an electrical wire? Which part of the nerve cell contains the nucleus?

6. Neurons interact with other neurons through synapses Synapse ….. junction between two neurons. "information" flows from one neuron to another

7. How do neurons communicate? Pre-synaptic cell Post synaptic cell Vesicle neurotransmitter (dendrite) (axon) receptors synapse

8. Neurotransmission animation

9. Now label on your diagram… Presynaptic neuron (axon) Postsynaptic neuron (dendrite) Synapse Vesicles Neurotransmitters Receptors Reuptake channels Draw an arrow showing the direction of impulse travel

10. Neurotransmitters Chemicals that transmit signals from a neuron to a target cell across a synapse Acetylcholine : muscles, memory Norepinephrine/epinephrine : fight/flight Serotonin : mood, appetite (depression) Histamine : Inflammation response Dopamine : pleasure Melatonin : sleep Endorphins: pain control

11. Check your understanding… What do you call the gap between two neurons? What chemicals take the signal across this gap? Name the neurotransmitter: Sleep Mood, appetite Inflammation Fight or flight Muscles, memory pleasure

12. Steps of Neuron Communication 1. Neuron at rest 2. Pre-synaptic neuron fires signal 3. Vesicle releases neurotransmitter 4. Neurotransmitter binds to receptor on post-synaptic neuron 5. Post-synaptic neuron fires signal 6. Neurotransmitters re-absorbed by pre-synaptic neuron 7. signal has been sent

13. Stimulant drugs increase number of signals fired Nicotine Moves through spaces between neurons Binds to nicotine receptor on pre-synaptic neuron Causes neuron to fire Causes release of dopamine If you flood your brain with nicotine, brain builds MORE nicotine receptors to suck it all up

14. Stimulant drugs increase number of signals fired Cocaine Present in extra-cellular space BLOCKS reuptake channel Synapse is flooded with dopamine

15. Stimulant drugs increase number of signals fired Methamphetamine Passes through membrane enters neuron Moves into vesicle Causes release of dopamine AND METH with signal Also blocks reuptake channel