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Whole-Mount Staining, Visualization, and Analysis of Fungiform, Circumvallate, and Palate Taste Buds
Published on: February 11, 2021
Acid-sensing ion channels in taste buds
Shoichi Shimada1, Takashi Ueda, Yusuke Ishida
1Department of Molecular Morphology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. sshimada@med.nagoya-cu.ac.jp
Archives of Histology and Cytology
|February 9, 2007
Summary
Researchers identified acid-sensing ion channels (ASICs) 2a and 2b as key players in detecting sour taste in rats. These ion channels are crucial for sour taste transduction, influencing how rats perceive acidity.
Area of Science:
- Neuroscience
- Sensory Biology
- Molecular Biology
Background:
- Taste receptor cells utilize ion channels and G protein-coupled receptors for stimulus detection.
- Sour and salty tastes in rats are primarily mediated by ion channels.
- Acid-sensing ion channels (ASICs) are implicated in taste perception.
Purpose of the Study:
- To identify the specific ion channels responsible for sour taste detection in rats.
- To investigate the role of acid-sensing ion channel-2a (ASIC2a) and ASIC2b in sour taste transduction.
Main Methods:
- Screening of a rat circumvallate papilla cDNA library using homology screening and functional expression.
- Localization studies using in situ hybridization and reverse transcription-polymerase chain reaction.
- Expression analysis via immunohistochemistry and immunoprecipitation.
- Electrophysiological studies to assess channel activity and pH sensitivity.
Main Results:
- ASIC2a and ASIC2b were identified as candidate sour-sensing channels in rats.
- ASIC2a and ASIC2b transcripts and proteins were found in specific taste bud cells, including heteromeric assemblies.
- Acetic acid stimulation produced larger ASIC2 currents than hydrochloric acid at the same pH.
- ASIC2a/ASIC2b channels showed maximal inward currents at pH ≤ 2.0, consistent with rat taste cell pH sensitivity.
- Amiloride sensitivity of ASIC2a/ASIC2b heteromers decreased with lower pH.
Conclusions:
- ASIC2a and ASIC2b are likely involved in the transduction of sour taste in rats.
- These channels contribute to the detection of acidic stimuli in the gustatory system.
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