Santiago Ramn y Cajal

(rod) (cone)

Rod-, cone- and melan- opsins

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Cyclic nucleotide-gated ion channels or CNG channelsHyperpolarization-activated cyclic nucleotide-gated (HCN) channels

Rhodopsin (Rh1, OPN2, RHO) expressed in rod cellsThree cone opsins (also known as photopsins) expressed in cone cells, used in color vision Long Wavelength Sensitive (OPN1LW) Opsin max in the red regionMiddle Wavelength Sensitive (OPN1MW) Opsin max in the green regionShort Wavelength Sensitive (OPN1SW) Opsin max in the blue region

, (G-)

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Cyclic AMP (cAMP) opens cyclic nucleotide-gated ion channels!

G protein-coupled receptors

G protein-coupled receptors

The Nobel Prize in Physiology or Medicine 2004 "or their discoveries of odorant receptors and the organization of the olfactory system "Richard AxelLinda B. Buck

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MECHANOELECTRICAL TRANSDUCTION

CADHERINS (calcium-dependent adhesion) - class transmembrane proteins

- 1/TMC2 (transmembrane channel-like 1)

-1/2

Shaker K+ channels

Shaker K+ channels

Transient receptor potential channels (TRP channels)

Transient receptor potential channels (TRP channels)

K+

, K+ Hibino H , and Kurachi Y Physiology 2006;21:336-3452006 by American Physiological Society

Schematic model of the K+-transport system in vestibuleA: vestibular dark cell area secretes K+ from perilymph to endolymph. Vestibular stimuli enter K+ into the vestibular hair cells (orange) from the endolymph. Note that vestibular endolymph contains 150 mM [K+] but that its potential is ~0 mV. B: cells composed of dark cell area and ion-transport apparatuses mediating vestibular K+ transport. Note that the molecules expressed in dark cells are similar to those in stria vascularis. However, there is neither intermediate cells nor basal cell layer in the vestibule.

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Acid-sensing ion channel (ASIC)

Transient receptor potential channels (TRP channels)

P2X

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Schematic model of the K+-transport system in vestibuleA: vestibular dark cell area secretes K+ from perilymph to endolymph. Vestibular stimuli enter K+ into the vestibular hair cells (orange) from the endolymph. Note that vestibular endolymph contains 150 mM [K+] but that its potential is ~0 mV. B: cells composed of dark cell area and ion-transport apparatuses mediating vestibular K+ transport. Note that the molecules expressed in dark cells are similar to those in stria vascularis. However, there is neither intermediate cells nor basal cell layer in the vestibule.