Lecture Objectives

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Lecture Objectives

• Introduce chemical sensation
• Anatomy and physiology of gustatory system
• Anatomy and physiology of olfactory system
• Anatomy and physiology of vomeronasal system

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Anatomy of Taste - Tongue
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Anatomy of Taste Taste Buds
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Anatomy of Taste Receptor Cells
50µm
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Taste Stimuli Elicit Action Potentials in Taste
Cells
Physiology of Taste - Stimuli
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Physiology of Taste - Transduction

• Stimulus/Receptor Interaction
• Membrane Depolarization
• Action Potential Initiation
• Calcium Influx
• Release of Transmitter
• Activation of Gustatory Afferent Neurons

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Taste Transduction - Salty
Amiloride-Sensitive Sodium Channels for Na
Transduction
Na
Na
ENaC
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Taste Transduction - Salty
a, b, and g ENaC are expressed
Epithelial Na Channel Superfamily
Fungiform
Foliate
Vallate
a
b
g
Waldmann Lazdunski (1998), Curr. Opin.
Neurobiol. 8418-424.
Lin, Finger, Rossier Kinnamon (1999),
J. Comp. Neurol. 405406-420.
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Taste Transduction - Sour
A Variety of Channels Mediate Sour Taste
H
Na
H
Na
Na
Na
ASIC
HCN
ENaC
K
K
ENaC Gilbertson TA, Roper SD, Kinnamon SC.
Neuron 1993 10931-42. ASICs Ugawa, Minami,
Guo, Saishin, Takatsuji, Yamamoto, Tohyama,
Shimada. Nature 1998 395555-6 HCN Stevens,
Seifert, Bufe, Muller, Kremmer, Gauss, Meyerhof,
Kaupp, Lindemann. Nature 2001 413631-5
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Sour Transduction in Taste Cells and Heterologous
Cells
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G Protein-Coupled Receptors Mediate Transduction
of Complex Taste Stimuli
Umami Chaudhari et al., Nat Neurosci. 2000
3113-9. Sweet Hoon et al., Cell.
1999,96(4)541-51. Li et al., Mamm Genome 2001
1213-6. Max et al., Nat Genet. 2001
May28(1)58-63. Montmayeur et al., Nat
Neurosci. 2001,4492-8. Nelson et al., Cell.
2001,106381-90. Bitter Chandrashekar et al.,
Cell 2000 100703-11. Adler et al., Cell.
2000,100693-702. Matsunami et al. Nature 2000
404601-4.
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Taste Transduction - Bitter
aGust McLaughlin SK, McKinnon PJ, Margolskee RF.
Nature 1992 18357563-9. Wong GT, Gannon KS,
Margolskee RF. Nature 1996 381796-800. b3g13 Hu
ang, Shanker, Dubauskaite, Zheng, Yan,
Rosenzweig, Spielman, Max, Margolskee. Nat
Neurosci 1999 21055-62. Rossler P, Boekhoff
I, Tareilus E, Beck S, Breer H, Freitag J. Chem
Senses 200025413-21. PLCb2 Rossler P, Kroner
C, Freitag J, Noe J, Breer H. Eur J Cell Biol
199877253-61. IP3R3 Clapp TR, Stone LM,
Margolskee RF, Kinnamon S. BMC Neurosci
20012(1)6 Miyoshi MA, Abe K, Emori Y. Chem
Senses 200126259-65
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Signaling Proteins in Bitter Transduction
Co-localization of Bitter Signaling Components
Bitter Stimuli Elicit Ca2 Release and Ca2
Influx
Clapp TR, Stone LM, Margolskee RF, Kinnamon
S. BMC Neurosci 20012(1)6
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Taste Transduction - Bitter
aGust McLaughlin SK, McKinnon PJ, Margolskee RF.
Nature 1992 18357563-9. Wong GT, Gannon KS,
Margolskee RF. Nature 1996 381796-800. b3g13 Hu
ang, Shanker, Dubauskaite, Zheng, Yan,
Rosenzweig, Spielman, Max, Margolskee. Nat
Neurosci 1999 21055-62. Rossler P, Boekhoff
I, Tareilus E, Beck S, Breer H, Freitag J. Chem
Senses 200025413-21. PLCb2 Rossler P, Kroner
C, Freitag J, Noe J, Breer H. Eur J Cell Biol
199877253-61. IP3R3 Clapp TR, Stone LM,
Margolskee RF, Kinnamon S. BMC Neurosci
20012(1)6 Miyoshi MA, Abe K, Emori Y. Chem
Senses 200126259-65
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Taste Transduction - Sweet
Cell 1062001, cover
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Taste Transduction - Sweet
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Pain / Temperature Pathway
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Pain / Temperature Pathway
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Pain / Temperature Pathway
From McKemy, Neuhausser and Julius. Nature,
March, 2002
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Anatomy of Olfaction - Nose
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Physiology of Olfaction
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Physiology of Olfaction - Transduction
OCNC Olfactory Cyclic Nucleotide Gated Channel
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Physiology of Olfaction - Receptors
Buck and Axel, Cell. 1991
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Physiology of Olfaction - Transduction
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Physiology of Olfaction - Coding
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Vomeronasal Organ - Phermones
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Physiology of Olfaction - Transduction