Auditory System Explained (Anatomy, Cochlear Transduction, Auditory Cortex) | Full discussion

Welcome to Science With Tal!

In this video, we will cover the auditory system from the periphery to the central nervous system and understand the sequence that leads to our ability to hear. We will cover topics such as the outer-, middle-, and inner ear with all the transduction steps required to convert sound energy into neural stimuli. We will also cover the anatomy of the central nervous system underlying the auditory pathways.

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TIMESTAMPS

0:00 Introduction
0:44 Sound terminology
4:55 Ear anatomy overview
5:24 Outer ear: anatomy
7:16 Middle ear: anatomy 1
10:06 Ossicles and acoustic impedance
13:13 Middle ear: anatomy 2
15:47 Inner ear: anatomy
18:43 Recap 1
19:12 Transduction: introductory terminology
22:04 Transduction: basilar membrane (uniform)
25:18 Transduction: basilar membrane (real)
29:50 Transduction: organ of Corti terminology
32:02 Transduction: IHC structure and K+ movement
38:52 Transduction: 1st step (MET channels)
41:23 Transduction: remaining steps
44:48 Recap 2
46:03 Outer hair cells and prestin
49:45 Innervation of cochlea (SGN)
52:02 Cochlea output: Phase-locking
54:04 Cochlea output: label-line coding
57:42 Recap 3
58:45 Overview of auditory system in the brain
1:05:20 Medulla/Pons: Anatomy CN and SOC
1:08:58 Medulla/Pons: Vertical localization (DCN)
1:09:57 Pons: Interaural time difference (ITD)
1:14:49 Pons: Interaural intensity difference (IID)
1:17:37 Pons: Efferent feedback (MOC & LOC)
1:19:19 Pons/Midbrain: Inferior colliculus
1:22:12 Thalamus and auditory cortex (core, belt, parabelt)
1:28:49 Conclusion

RESOURCES

Here is a list of the resources that I’ve used to produce this video. (Main author: title resource)

Textbooks
1. Kandel: Principles of Neural Science (6th ed., 2021)
2. Purves: Neuroscience (6th ed., 2017)

Scientific articles
3. Heine: Anatomy of the ear (2004)
https://pubmed.ncbi.nlm.nih.gov/15062...

4. Kimura: The ultrastructure of the organ of Corti (1975)
https://pubmed.ncbi.nlm.nih.gov/1104509/

5. Thulasiram: Hearing Function, Degeneration, and Disease: Spotlight on the Stria Vascularis (2022)
https://pubmed.ncbi.nlm.nih.gov/35309...

6. Pujol: Pathophysiology of the glutamatergic synapses in the cochlea (1993)
https://pubmed.ncbi.nlm.nih.gov/8100108/

7. Guinan JR: Cochlear efferent innervation and function (2011)
https://pmc.ncbi.nlm.nih.gov/articles...

8. Nin: The endocochlear potential depends on two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear (2008)
https://pmc.ncbi.nlm.nih.gov/articles...

9. Zdebik: Potassium Ion Movement in the Inner Ear: Insights from Genetic Disease and Mouse Models (2009)
https://pmc.ncbi.nlm.nih.gov/articles...

10. Ashmore: Outer Hair Cells and Electromotility (2019)
https://pubmed.ncbi.nlm.nih.gov/30181...

11. Fuchs: Efferent Inhibition of the Cochlea (2019)
https://pubmed.ncbi.nlm.nih.gov/30082...

12. Raphael: Structure and innervation of the cochlea (2003)
https://pubmed.ncbi.nlm.nih.gov/12787...

13. Pickles: Auditory pathways: anatomy and physiology (2013)
https://pubmed.ncbi.nlm.nih.gov/25726...

14. Eggermont: Cochlea and auditory nerve (2019)
https://pubmed.ncbi.nlm.nih.gov/31277...

15. Rutherford: Encoding sound in the cochlea: from receptor potential to afferent discharge (2021)
​​https://pubmed.ncbi.nlm.nih.gov/33644...

16. Romero: Central circuitry and function of the cochlear efferent systems (2022)
https://pubmed.ncbi.nlm.nih.gov/35606...

17. Liu: Research progress of the inferior colliculus: from Neuron, neural circuit to auditory disease (2024)
https://pubmed.ncbi.nlm.nih.gov/38244...

18. Rauschecker: Anatomy of the auditory cortex then and now (2023)
https://pubmed.ncbi.nlm.nih.gov/38010...

19. Lestang: Functional network properties of the auditory cortex (2023)
https://pubmed.ncbi.nlm.nih.gov/37075...

20. Driscolie: Neuroanatomy, Inferior Colliculus (2023)
https://www.ncbi.nlm.nih.gov/books/NB...

21. Ruthig: Common principles in the lateralization of auditory cortex structure and function for vocal communication in primates and rodents (2022)
https://pubmed.ncbi.nlm.nih.gov/34984...

CREDITS

Writing: Tal Klimenko
Voice: Tal Klimenko
Animations: Tal Klimenko
Drawings: Tal Klimenko
Editing: Tal Klimenko
Introductory jingle: Thierry Du Sablond
Conclusion music: lukrembo - sunflower (   • lukrembo - sunflower (no copyright music)  )