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Neural Communication
Psychology 2606
Introduction
It was pretty clear early on that electricity
played a role of some sort in neural
communication
 Galvani, frogs’ legs and lightning
 Fritsch and Hitzig stimulated cortex of
various animals, got twitches
 Bartholow and Mary Rafferty
 Dr. Penfield, I smell burnt toast
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EEGs are AOK
Caton
 Helmholtz
 Hodgkin, Huxley and giant axons
 Used mircorelectrodes and oscilloscopes
to measure the resting potential of a
neuron
 -70 mV
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Electrical activity of the neuron
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Resting potential
About -70 mV
 Selectively allowing certain ions in
 With stimulation Na+ is allowed in
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Action potential
Changes in one area lead to changes in
another
 Chemical to electrical, very cool
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The Sodium Potassium Pump
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Active transport takes
energy
Easier encoding?
Faster reaction?
An Action potential
happens when
stimulation causes the
pump to sort of stop, Na
gets in, K goes out
Sort of reversed later
integration
Excitatory postsynaptic potentials
 Inhibitory postsynaptic potentials
 Temporal summation
 Spatial summation
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The axon Hillock
Where the axon starts
 many voltage sensitive channels
 Need oh say -50 mV for depolarization
 Not all graded potentials are equal
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Sensation and movement
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Receptors for
Light
Sound
Smell
Taste
Touch
Pain
Cold
heat
movement
Neuron synapses onto end plate
 Big channels
 Acetylcholine
 Ach antagonists can cause paralysis
 Curare
 Sarin
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EEG
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Oldest form of brain
imaging
CAT Scan
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Computerized axial
tomography
PET scan
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Positron emission
tomography
MRI
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Magnetic Resonance
Imaging
ERPs and single cells
Event related potentials
 Used to see what is lit up, pretty cheap
 Single cell recording uses micro
electrodes
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