TY - JOUR
T1 - Presynaptic (Type III) cells in mouse taste buds sense sour (acid) taste
AU - Huang, Yijen A.
AU - Maruyama, Yutaka
AU - Stimac, Robert
AU - Roper, Stephen D.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/6/15
Y1 - 2008/6/15
N2 - Taste buds contain two types of cells that directly participate in taste transduction - receptor (Type II) cells and presynaptic (Type III) cells. Receptor cells respond to sweet, bitter and umami taste stimulation but until recently the identity of cells that respond directly to sour (acid) tastants has only been inferred from recordings in situ, from behavioural studies, and from immunostaining for putative sour transduction molecules. Using calcium imaging on single isolated taste cells and with biosensor cells to identify neurotransmitter release, we show that presynaptic (Type III) cells specifically respond to acid taste stimulation and release serotonin. By recording responses in cells isolated from taste buds and in taste cells in lingual slices to acetic acid titrated to different acid levels (pH), we also show that the active stimulus for acid taste is the membrane-permeant, uncharged acetic acid moiety (CH3COOH), not free protons (H+). That observation is consistent with the proximate stimulus for acid taste being intracellular acidification, not extracellular protons per se. These findings may also have implications for other sensory receptors that respond to acids, such as nociceptors.
AB - Taste buds contain two types of cells that directly participate in taste transduction - receptor (Type II) cells and presynaptic (Type III) cells. Receptor cells respond to sweet, bitter and umami taste stimulation but until recently the identity of cells that respond directly to sour (acid) tastants has only been inferred from recordings in situ, from behavioural studies, and from immunostaining for putative sour transduction molecules. Using calcium imaging on single isolated taste cells and with biosensor cells to identify neurotransmitter release, we show that presynaptic (Type III) cells specifically respond to acid taste stimulation and release serotonin. By recording responses in cells isolated from taste buds and in taste cells in lingual slices to acetic acid titrated to different acid levels (pH), we also show that the active stimulus for acid taste is the membrane-permeant, uncharged acetic acid moiety (CH3COOH), not free protons (H+). That observation is consistent with the proximate stimulus for acid taste being intracellular acidification, not extracellular protons per se. These findings may also have implications for other sensory receptors that respond to acids, such as nociceptors.
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U2 - 10.1113/jphysiol.2008.151233
DO - 10.1113/jphysiol.2008.151233
M3 - Article
C2 - 18420705
AN - SCOPUS:45249103556
VL - 586
SP - 2903
EP - 2912
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 12
ER -