1. Action potential This is how neurons communicate with each other
Fluid outside the axon membrane has mostly positively charged ions (+)
At rest, the fluid interior of an axon has negatively charged particles
This state is called the resting potential
The surface of the axon is selectively permeable

2. Action Potential: Electrical & Chemical Communication
A brief electro/chemical signal that travels down the axon to the terminal buttons.

6. The Synapse
A junction between the terminal buttons of the sending cell and a portion of the membrane of the receiving cell

7. Threshold and firing the action potential…

8. The Flow of Transmission
Intensity comes from quantity of neurons firing and frequency of firing but the action potential’s strength and speed are constant

9. Keys in the lock Neurotransmitter – the key fits in nicely
Agonist – (excites) mimics the neurotransmitter and stimulates the receptor
Antagonist – (inhibits) blocks and does not stimulate the receptor

10. Four ways neurotransmitters are inactivated
1. Diffusion: the neurotransmitter drifts away, out of the synaptic cleft where it can no longer act on a receptor.
2. Enzymatic degradation (deactivation): a specific enzyme changes the structure of the neurotransmitter so it is not recognized by the receptor.
Acetylcholinesterase is the enzyme that breaks acetylcholine into choline and acetate.
3. Glial cells: astrocytes remove neurotransmitters from the synaptic cleft.
4. Reuptake: the whole neurotransmitter molecule is taken back into the axon terminal that released it. This is a common way the action of norepinephrine, dopamine and serotonin is stopped...these neurotransmitters are removed from the synaptic cleft so they cannot bind to receptors.

11. Done talking!
Grab a text book and start mapping neurons and information about them – use text and images and MAKE IT MEANINGFUL TO YOU!

13. A Closer Look at a Terminal Button
Neurotransmitter
endogenous* chemical messengers that cross the synaptic gaps between neurons
* originates within the organism
synapse - hyperlink

14. Keys in the lock Neurotransmitter – the key fits in nicely
Agonist – (excites) mimics the neurotransmitter and stimulates the receptor
Antagonist – (inhibits) blocks and does not stimulate the receptor

15. Neurotransmitters Serotonin Dopamine Acetylcholine Norepinephrine GABA
Substance P
Endorphins
Hyperlink

17. A Closer Look at Reuptake
the process by which the sending neurons collect the excess neurotransmitter
hyperlink

18. Pathways
40 billion neurons each connect to approx other neurons, thus we end up with possibly 400 trillion synapses
Neurons cluster into neural networks
Neurotransmitter pathways – may use only one or two neurotransmitters and neurotransmitters may affect specific behaviours and emotions
Learning occurs as experience strengthens connections

19. Two key pathways

20. Dopamine pathways
The most important reward pathways in the brain and work as a key detector of a rewarding stimulus
Under normal conditions dopamine pathways control an individual's responses to natural rewards, such as food, sex, and social interactions, and is important for motivation
Activation of the pathway tells the individual to repeat what it just did to get that reward and tells the memory centers in the brain to pay particular attention to all features of that rewarding experience, so it can be repeated in the future

21. https://www. ted. com/talks/nicole_avena_how_sugar_affects_the_brain

22. Plasticity
This is the brain’s ability to change, especially during childhood
Reorganizing after damage or building new pathways based on new experiences or neurogenesis (new brain cells produced)
Not all damage can be remediated – neurons that are severed usually do not regenerate
Neurons that fire together, wire together
We have synaptic pruning but we also have creation of synapses