1. Mind, Brain & Behavior
Friday
January 31, 2003

2. For Midterm 1
Chapters 1, 2, 4, 5
Lecture on Mind-Body (not in textbook)
“An Overview View” – Chap. 6, 7, 8, 9, 13
Class lectures on topics that are covered in greater detail in Chapters 6-9, 13
Use the overheads as a study guide
Do be able to identify the parts of the brain and the parts of a neuron on a diagram.

3. Synaptic Integration
Chapter 13

4. Two Kinds of Input Excitatory post-synaptic potential (EPSP)
An ion channel admits a positively charged ion, causing depolarization.
If enough excitation occurs, an action potential is triggered.
Inhibitory post-synaptic potential (IPSP)
An ion channel admits a negatively charged ion.
The membrane becomes hyperpolarized, making it less likely an action potential will occur.

5. Integration of Signals
Neuronal integration – competing signals are integrated to decide whether or not to fire.
Decision is made at the trigger point (usually the axon hillock).
Net input above threshold causes an action potential.
Signals can be summed over time (temporally) or spatially (within a given location in the neuron).

6. Location of Synapses
Where a synapse occurs on the neuron is often related to its action:
Synapses on cell body are often inhibitory
Synapses on dendritic spines are often excitatory
Synapses on axon terminals are often modulatory, controlling amount of neurotransmitter released

7. Four Kinds of Neurotransmitters
Cholinergic – acetylcholine (ACh)
Catecholamines
Dopamine (DA)
Norepinephrine (noradrenaline) (NE)
Epinephrine (adrenaline)
Serotonergic – serotonin (5-HT)
Amino Acids
GABA, glutamate (Glu), gylcine (Gly)

8. Other Intercellular Messengers
Peptides
Hormones
ATP (adenosine triphosphate) – packaged and released with another transmitter
Nitric oxide (NO) – retrograde messenger acting on the presynaptic neuron

9. G-Protein Coupled Receptors
The purpose of G-protein receptors is modulation of neural responsivity.
G-proteins start the process of phosphorylation which makes a neuron more sensitive to excitatory signals.
Inhibits potassium channel to lengthen EPSP.
The binding neurotransmitter starts a cascade of biochemical events leading to widespread changes spread by second messengers.

10. Uses of G-Proteins Muscarinic receptors of the heart.
Enables ACh to slow heart rate.
Shortcut pathway is fast and localized.
Push-pull regulation using second-messengers:
Elevation of CA++ in cytosol causes widespread and long-lasting effects.
Signal amplification – activation of one G-protein channel affects many ion channels.