The document discusses several key topics related to neuronal properties and function, including: 1) How action potentials are generated and regulated within neurons via ion movements and refractory periods. 2) How the frequency of action potentials is related to the strength of stimuli and neurotransmitter release. 3) How action potentials are conducted along axons via depolarization and at differing speeds depending on factors like myelination and diameter. 4) How communication occurs between neurons at chemical synapses, involving the release and binding of neurotransmitters.

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Neurons:
Cellular and Network Properties
• Neurons:
Cellular and Network Properties
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2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
• Positive feedback loop
• Absolute refractory period
• Relative refractory period
Regulating the AP
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3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Regulating the AP
Figure 8-11: Ion movements during the action potential
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Regulating the AP
Figure 8-12: Refractory periods
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• Firing rate
• "Wave" of APs
• Proportional neurotransmitter (NT) release
• Stronger GP initiates more APs & more NT
Frequency of Action Potentials
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Frequency of Action Potentials
Figure 8-13: Coding for stimulus intensity
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7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
• Kinetic energy
• Depolarizes ahead
• Drives AP to terminal
Conduction of Action Potentials
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Conduction of Action Potentials
Figure 8-14a: Conduction of action potentials
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Conduction of Action Potentials
Figure 8-14b: Conduction of action potentials
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Conduction of Action Potentials
Figure 8-14c: Conduction of action potentials
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• Larger diameter faster conduction
• Myelinated axon faster conduction
• Salutatory conduction
• Disease damage to myelin
• Chemicals that block channels
• Alteration of ECF ion concentrations
Speed of Conduction
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12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Speed of Conduction
Figure 8-16b: Axon diameter and speed of conduction
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13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Speed of Conduction
Figure 8-17: Saltatory conduction
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14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Cell to Cell Conduction: the Synapse
• Electrical synapses: gap junctions
• Very fast conduction
• Example: cardiac muscle
• Chemical synapses
• Pre synaptic terminal
• Synthesis of Neurotransmitters
• Ca2+
releases Neurotransmitters
• Synaptic cleft
• Postsynaptic cell: Neurotransmitter receptors
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Cell to Cell Conduction: the Synapse
Figure 8-19: A chemical synapse
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Synapse Mechanism
Figure 8-20: Events at the synapse
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Acetylcholine synthesis
Figure 8-21: Synthesis and recycling of acetylcholine at the synapse
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• Neurotransmitters
• Neuromodulators
• Neurohormones
Neurocrines
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19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Neurocrines
Table 8-4-1: Major Neurocrines
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20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Neurocrines
Table 8-4-2: Major Neurocrines
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