Start of Part 3

Eric W. Harris, PhD.

Basic Functional Subdivision of Neurons

But, of course, there are exceptions – e.g., action potentials can originate from axon terminals and “back propagate”

“Integration” of excitatory inputs

http://web.lemoyne.edu/~hevern/psy340_11S/lectures/psy340.03.1.synapse.outline.html

Basic Functional Subdivision of Neurons

But, of course, there are exceptions – e.g., action potentials can originate from axon terminals and “back propagate”

How neurons send a signal – Pt. 1 The “Action Potential”

http://neuroscience.uth.tmc.edu/s1/chapter01.html

Basic Functional Subdivision of Neurons

But, of course, there are exceptions – e.g., action potentials can originate from axon terminals and “back propagate”

How neurons send a signal – Part 2: Synaptic Transmission

http://commons.wikimedia.org/wiki/File:SynapseIllustration2.png

Analogies of how neurons work

Neurotransmitters

Glutamate, Aspartate - major excitatory neurotransmitters in the brain

GABA - major inhibitory neurotransmitter in the brain

Acetylcholine - many different actions in the brain; neuromuscular junction transmitter

Serotonin – many different actions; associated with mood, sleep, perception (LSD)

Dopamine – many different effects; associated with reward, attention, movement (PD)

Opioid peptides (endorphins) – modulate pain signals

Substance P – pain signaling

Many others…

Summary of basic information processing in the brain

http://biomedicalengineering.yolasite.com/neurons.php

Action Potential

Action Potential

Synapse…

But it’s not so simple - Excitation and Inhibition

http://neuroscience.uth.tmc.edu/s1/introduction.html

Physiological plasticity

Synapses are not static: With repeated use can show “habituation” With intense use can become stronger (“long-term potentiation”)

Simultaneous strong inputs can potentiate each other (“fire together, wire together”)

Harris & Cotman, 1986

Electroencephalography (EEG)

http://www.brightmindsinstitute.com/blog/

http://quizlet.com/4239544/cog-sci-chapter-2-flash-cards/http://www.acm.org/conferences/sac/sac2000/Proceed/FinalPapers/BC-07/

http://apotential.wordpress.com/2012/07/11/the-neurologist-explains-eegs-to-me/

Synaptic currents create a small electrical field along a neuron

If neurons are lined up, the electric fields add together.

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Using electrodes placed on the scalp and sensitive amplifiers…

…one can record “brain waves”!

Quantitative EEG (QEEG)

EEG is the sum of manybrain waves, like this:

EEG can be “de-convoluted” to find and measure the underlying components, e.g.:

Frequency (Hz)0

scidavis.sourceforge.net/manual/c4166.htmlnewsoffice.mit.edu/2012/faster-fourier-transforms-0118

QEEG data can be looked at many ways,For example:

http://simetronsac.com/dx_eeg2.php

And then there are glial cells…

Astrocyte – various supportive functions

Oligodendrocyte - makes myelin

The building blocks – Neurons and Glial Cells

Ramon y Cajal, 1899

Miriam Ascagni, DIBIT San Raffaele Scientific Institute, Italy, 2010

Del Rio-Hortega, 1920 http://www.nedsahin.com/methods/fmri/

Good sources of info about the brain,

The Society for Neuroscience (www.sfn.org) – in particular, “Brain Briefings”

“The Brain Science Podcast” – not for total beginners

The Dana Foundation www.dana.org

http://faculty.washington.edu/chudler/neurok.html (“Neuroscience for Kids”)

http://medicalxpress.com/neuroscience-news/

There is LOTS of new information every day…

Thank you for your attention

Questions? Comments?