In physiology, transduction is the translation of arriving stimulus into an action potential by a sensory receptor. It begins when stimulus changes the membrane potential of a sensory receptor.
A sensory receptor converts the energy in a stimulus into an electrical signal. Receptors are broadly split into two main categories: exteroceptors, which receive external sensory stimuli, and interoceptors, which receive internal sensory stimuli.
Sensory transduction
The visual system
In the visual system, sensory cells called rod and cone cells in the retina convert the physical energy of light signals into electrical impulses that travel to the brain. The light causes a conformational change in a protein called rhodopsin. This conformational change sets in motion a series of molecular events that result in a reduction of the electrochemical gradient of the photoreceptor. The decrease in the electrochemical gradient causes a reduction in the electrical signals going to the brain. Thus, in this example, more light hitting the photoreceptor results in the transduction of a signal into fewer electrical impulses, effectively communicating that stimulus to the brain. A change in neurotransmitter release is mediated through a second messenger system. The change in neurotransmitter release is by rods. Because of the change, a change in light intensity causes the response of the rods to be much slower than expected (for a process associated with the nervous system).
The auditory system
In the auditory system, sound vibrations (mechanical energy) are transduced into electrical energy by hair cells in the inner ear. Sound vibrations from an object cause vibrations in air molecules, which in turn, vibrate the ear drum. The movement of the eardrum causes the bones of the middle ear (the ossicles) to vibrate. These vibrations then pass into the cochlea, the organ of hearing. Within the cochlea, the hair cells on the sensory epithelium of the organ of Corti bend and cause movement of the basilar membrane. The membrane undulates in different sized waves according to the frequency of the sound. Hair cells are then able to convert this movement (mechanical energy) into electrical signals (graded receptor potentials) which travel along auditory nerves to hearing centres in the brain.
The olfactory system
In the olfactory system, odorant molecules in the mucus bind to G-protein receptors on olfactory cells. The G-protein activates a downstream signalling cascade that causes increased level of cyclic-AMP (cAMP), which trigger neurotransmitter release.
The gustatory system
In the gustatory system, perception of five primary taste qualities (sweet, salty, sour, bitter and umami [savoriness] ) depends on taste transduction pathways, through taste receptor cells, G proteins, ion channels, and effector enzymes.
The somatosensory system
In the somatosensory system the sensory transduction mainly involves the conversion of the mechanical signal such as pressure, skin compression, stretch, vibration to electro-ionic impulses through the process of mechanotransduction. It also includes the sensory transduction related to thermoception and nociception.
References
- Lodish, Harvey F. (2000). Molecular cell biology (4th ed.). New York: W.H. Freeman. ISBN 0-7167-3136-3. OCLC 41266312.
- "Definition of EXTEROCEPTOR". www.merriam-webster.com. Retrieved 2018-03-29.
- "Definition of INTEROCEPTOR". www.merriam-webster.com. Retrieved 2018-03-29.
- Silverthorn, Dee Unglaub. Human Physiology: An Integrated Approach, 3rd Edition, Inc, San Francisco, CA, 2004.
- Koike, Takuji; Wada, Hiroshi; Kobayashi, Toshimitsu (2002). "Modeling of the human middle ear using the finite-element method". The Journal of the Acoustical Society of America. 111 (3): 1306–1317. Bibcode:2002ASAJ..111.1306K. doi:10.1121/1.1451073. PMID 11931308.
- W., Clark, William (2008). Anatomy and physiology of hearing for audiologists. Ohlemiller, Kevin K. Clifton Park, NY: Thomson Delmar. ISBN 978-1-4018-1444-1. OCLC 123956006.
{{cite book}}: CS1 maint: multiple names: authors list (link) - Eatock, R. (2010). Auditory receptors and transduction. In E. Goldstein (Ed.), Encyclopedia of perception. (pp. 184-187). Thousand Oaks, CA: SAGE Publications, Inc. doi:10.4135/9781412972000.n63
- Ronnett, Gabriele V.; Moon, Cheil. L (2002). "G Proteins and Olfactory Signal Transduction". Annual Review of Physiology. 64 (1): 189–222. doi:10.1146/annurev.physiol.64.082701.102219. PMID 11826268.
- Timothy A Gilbertson; Sami Damak; Robert F Margolskee, "The molecular physiology of taste transduction", Current Opinion in Neurobiology (August 2000), 10 (4), pg. 519-527
- Biswas, Abhijit; Manivannan, M.; Srinivasan, Mandyam A. (2015). "Vibrotactile Sensitivity Threshold: Nonlinear Stochastic Mechanotransduction Model of the Pacinian Corpuscle". IEEE Transactions on Haptics. 8 (1): 102–113. doi:10.1109/TOH.2014.2369422. PMID 25398183. S2CID 15326972.
In physiology transduction is the translation of arriving stimulus into an action potential by a sensory receptor It begins when stimulus changes the membrane potential of a sensory receptor Principal steps of sensory processing A sensory receptor converts the energy in a stimulus into an electrical signal Receptors are broadly split into two main categories exteroceptors which receive external sensory stimuli and interoceptors which receive internal sensory stimuli Sensory transductionThe visual system In the visual system sensory cells called rod and cone cells in the retina convert the physical energy of light signals into electrical impulses that travel to the brain The light causes a conformational change in a protein called rhodopsin This conformational change sets in motion a series of molecular events that result in a reduction of the electrochemical gradient of the photoreceptor The decrease in the electrochemical gradient causes a reduction in the electrical signals going to the brain Thus in this example more light hitting the photoreceptor results in the transduction of a signal into fewer electrical impulses effectively communicating that stimulus to the brain A change in neurotransmitter release is mediated through a second messenger system The change in neurotransmitter release is by rods Because of the change a change in light intensity causes the response of the rods to be much slower than expected for a process associated with the nervous system The auditory system In the auditory system sound vibrations mechanical energy are transduced into electrical energy by hair cells in the inner ear Sound vibrations from an object cause vibrations in air molecules which in turn vibrate the ear drum The movement of the eardrum causes the bones of the middle ear the ossicles to vibrate These vibrations then pass into the cochlea the organ of hearing Within the cochlea the hair cells on the sensory epithelium of the organ of Corti bend and cause movement of the basilar membrane The membrane undulates in different sized waves according to the frequency of the sound Hair cells are then able to convert this movement mechanical energy into electrical signals graded receptor potentials which travel along auditory nerves to hearing centres in the brain The olfactory system In the olfactory system odorant molecules in the mucus bind to G protein receptors on olfactory cells The G protein activates a downstream signalling cascade that causes increased level of cyclic AMP cAMP which trigger neurotransmitter release The gustatory system In the gustatory system perception of five primary taste qualities sweet salty sour bitter and umami savoriness depends on taste transduction pathways through taste receptor cells G proteins ion channels and effector enzymes The somatosensory system In the somatosensory system the sensory transduction mainly involves the conversion of the mechanical signal such as pressure skin compression stretch vibration to electro ionic impulses through the process of mechanotransduction It also includes the sensory transduction related to thermoception and nociception ReferencesLodish Harvey F 2000 Molecular cell biology 4th ed New York W H Freeman ISBN 0 7167 3136 3 OCLC 41266312 Definition of EXTEROCEPTOR www merriam webster com Retrieved 2018 03 29 Definition of INTEROCEPTOR www merriam webster com Retrieved 2018 03 29 Silverthorn Dee Unglaub Human Physiology An Integrated Approach 3rd Edition Inc San Francisco CA 2004 Koike Takuji Wada Hiroshi Kobayashi Toshimitsu 2002 Modeling of the human middle ear using the finite element method The Journal of the Acoustical Society of America 111 3 1306 1317 Bibcode 2002ASAJ 111 1306K doi 10 1121 1 1451073 PMID 11931308 W Clark William 2008 Anatomy and physiology of hearing for audiologists Ohlemiller Kevin K Clifton Park NY Thomson Delmar ISBN 978 1 4018 1444 1 OCLC 123956006 a href wiki Template Cite book title Template Cite book cite book a CS1 maint multiple names authors list link Eatock R 2010 Auditory receptors and transduction In E Goldstein Ed Encyclopedia of perception pp 184 187 Thousand Oaks CA SAGE Publications Inc doi 10 4135 9781412972000 n63 Ronnett Gabriele V Moon Cheil L 2002 G Proteins and Olfactory Signal Transduction Annual Review of Physiology 64 1 189 222 doi 10 1146 annurev physiol 64 082701 102219 PMID 11826268 Timothy A Gilbertson Sami Damak Robert F Margolskee The molecular physiology of taste transduction Current Opinion in Neurobiology August 2000 10 4 pg 519 527 Biswas Abhijit Manivannan M Srinivasan Mandyam A 2015 Vibrotactile Sensitivity Threshold Nonlinear Stochastic Mechanotransduction Model of the Pacinian Corpuscle IEEE Transactions on Haptics 8 1 102 113 doi 10 1109 TOH 2014 2369422 PMID 25398183 S2CID 15326972
