start of part 3 eric w. harris, phd.. basic functional subdivision of neurons but, of course, there...

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.

xx

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?