neurons sepT. 18, 2017 – DAY 9 Brain & Language LING 4110-4890-5110-7960 NSCI 4110-4891-6110 Harry Howard Tulane University

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University Course organization http://www.tulane.edu/~h0Ward/BrLg/ Fun with https://www.facebook.com/BrLg17/

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University Review The quiz was the review.

Change in organization 18-sep-17 Brain & Language - Harry Howard - Tulane University Change in organization Old New Background Introduction to the course The fields of linguistics The macrostructure of the brain Speech Sound Speech sounds and their articulation Auditory transduction Subcortical audition The auditory cortex The superior temporal sulcus Wernicke’s aphasia Leftovers The microstructure of the brain Methodologies Background Introduction to the course My philosophy of teaching The fields of linguistics Sound Speech sounds and their articulation The extended ascending auditory pathway Perception Auditory transduction The microstructure of the brain (neurons) Subcortical audition The macrostructure of the brain (cortex) The auditory cortex The superior temporal sulcus Wernicke’s aphasia

Auditory transduction 18-sep-17 Brain & Language - Harry Howard - Tulane University Auditory transduction Review

Anatomy of the human ear 18-sep-17 Brain & Language - Harry Howard - Tulane University Anatomy of the human ear

Sample frequency cross-sections of the coiled cochlea, in Hertz 18-sep-17 Brain & Language - Harry Howard - Tulane University Sample frequency cross-sections of the coiled cochlea, in Hertz tonotopy: a mapping from sound frequency to place on the basilar membrane

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University Sample frequency cross-sections of an uncoiled cochlea, in Hertz [tonotopy]

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University Hair cells along the basilar membrane [this is what I want to explain today] http://tuningpp.com/organ-of-corti-hair-cells/2/

Ascending auditory pathway 1 (not review) 18-sep-17 Brain & Language - Harry Howard - Tulane University Ascending auditory pathway 1 (not review) 300px-Hearing_mechanics_cropped_A1.jpg

Ascending auditory pathway 2 (not review) 18-sep-17 Brain & Language - Harry Howard - Tulane University Ascending auditory pathway 2 (not review) 666669_m.png

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University Neurons

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University A pyramidal neuron

Electrical activity of neurons 18-sep-17 Brain & Language - Harry Howard - Tulane University Electrical activity of neurons Each neuron consists of a cell body, short threadlike projections called dendrites, and one longer thread called an axon. Impulses travel within a neuron in the form of electrical signals, but between them as chemical signals. The electrical signal is changed to a chemical one at the synapse, and then changed back to an electrical one on the other side of the synapse. post-synaptic, dendrites pre-synaptic, axon http://www.helcohi.com/sse/body/nervous.html

Another way of saying it 18-sep-17 Brain & Language - Harry Howard - Tulane University Another way of saying it http://www.uic.edu/classes/bios/bios100/lectures/nervous.htm

Electrical-chemical-electrical communication at the synapse http://txtwriter.com/Backgrounders/Drugaddiction/synapse.jpg 18-sep-17 Brain & Language - Harry Howard - Tulane University

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University A bit of cell membrane

Electrical and hydraulic models 18-sep-17 Brain & Language - Harry Howard - Tulane University Electrical and hydraulic models

The Hodgkin-Huxley model 18-sep-17 Brain & Language - Harry Howard - Tulane University The Hodgkin-Huxley model

Close-up of an action potential 18-sep-17 Brain & Language - Harry Howard - Tulane University Close-up of an action potential

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University A spike train

Layout of dendrites of pyramidal cells 18-sep-17 Brain & Language - Harry Howard - Tulane University Layout of dendrites of pyramidal cells apical dendrites basal dendrites http://www.nature.com/nrn/journal/v9/n3/fig_tab/nrn2286_F1.html

Axons vs. apical dendrites (in cortex) 18-sep-17 Brain & Language - Harry Howard - Tulane University Axons vs. apical dendrites (in cortex) Axons are oriented randomly along the cortical sheet, which results in their potentials cancelling one other out. Apical dendrites are oriented in parallel along the cortical sheet, which results in their potentials to reinforce one another and sum together, creating a large “dipole”, which is measurable with EEG/MEG.

Hair cells along the basilar membrane 18-sep-17 Brain & Language - Harry Howard - Tulane University Hair cells along the basilar membrane http://tuningpp.com/organ-of-corti-hair-cells/2/

The physical basis of the cognitive attributes of sound 18-sep-17 Brain & Language - Harry Howard - Tulane University The physical basis of the cognitive attributes of sound Physical Neural coding Cognitive quantity duration of spike trains duration frequency tonotopy: frequency-to-place mapping tone intensity rate (of action potential firing) loudness

Brain & Language - Harry Howard - Tulane University 18-sep-17 Brain & Language - Harry Howard - Tulane University NEXT TIME Ascending auditory pathway (sub-cortical audition)