Transcript Slides on Neural Communication

Slides On
Neural Communication
Ions & The Neural Membrane
• Electrical gradient (opposites attract)
• Concentration gradient (high  low)
• Sodium-potassium pumps
Na+
3 Na+
Very energy
expensive
2 K+
K+
Action Potential Activity
• Depolarization
• Repolarization
• Hyperpolarization

+30
mV
-60
-70




Time
NA+
Channels




K+
Channels


NA+ / K+
Pumps

The Big Picture

+30
mV
-60
-70
Action Potential



Time 
At the Synapse
1. Resting potential
2. Threshold is reached at the axon
hillock, sodium channels open
causing rapid depolarization
3. Potassium channels open
4. Sodium channels close
starting repolarization
5. Potassium channels close,
hyperpolarization
6. Sodium-potassium pumps
bring back to -70mV
1. Synaptic vesicles move to the end
of terminal button
2. Vesicles open into the synapse
3. Neurotransmitters are released into
the synapse
4. Neurotransmitters bind with
postsynaptic receptors
5. Excess neurotransmitter
is eliminated by reuptake or
enzymatic deactivation