Biomaterial Database

The ionic basis of the receptor potential of frog taste cells induced by water stimuli. 1993

Y Okada, and T Miyamoto, and T Sato

Department of Physiology, Nagasaki University School of Dentistry, Japan.

The ionic mechanism underlying the receptor potential induced by a deionized water stimulus was studied in frog taste cells with conventional microelectrodes. The taste cells located in the proximal portion of the tongue generated a depolarizing receptor potential which averaged 10mV in response to stimulation with deionized water. The cell membrane of the water-sensitive taste cell could be divided into the taste-receptive (apical) and basolateral membranes and the cells were classified into two types: Cl(-)-dependent and Cl(-)-independent. In Cl(-)-dependent cells whose input resistance was decreased or unchanged by deionized water, the magnitude of the water-induced depolarization decreased with an increase in concentration of superficial Cl- in contact with the receptive membrane and with addition of blockers of anion channels (0.1 mmol l-1 SITS and 0.1 mmol l-1 DIDS) to deionized water. The reversal potential for the depolarization in this type shifted according to the concentration of superficial Cl-. These properties of the responses were consistent with those of the glossopharyngeal nerve which innervates the taste disc. In Cl(-)-independent cells whose input resistance was increased by deionized water, the reversal potential was approximately equal to the equilibrium potential for K+ at the basolateral membrane. The water-induced response of the glossopharyngeal nerve was decreased to about 60% of the control value by addition of interstitial 2 mmol l-1 Ba2+. It is concluded that the water-induced receptor potential is produced by Cl- secretion through the taste-receptive membrane in about 70% of water-sensitive frog taste cells, while it is generated by an inhibition of the resting K+ conductance of the basolateral membrane in the remaining 30% of the cells.

UI	MeSH Term	Description	Entries
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D005930	Glossopharyngeal Nerve	The 9th cranial nerve. The glossopharyngeal nerve is a mixed motor and sensory nerve; it conveys somatic and autonomic efferents as well as general, special, and visceral afferents. Among the connections are motor fibers to the stylopharyngeus muscle, parasympathetic fibers to the parotid glands, general and taste afferents from the posterior third of the tongue, the nasopharynx, and the palate, and afferents from baroreceptors and CHEMORECEPTOR CELLS of the carotid sinus.	Cranial Nerve IX,Ninth Cranial Nerve,Cranial Nerve IXs,Cranial Nerve, Ninth,Cranial Nerves, Ninth,Glossopharyngeal Nerves,Nerve, Glossopharyngeal,Nerve, Ninth Cranial,Nerves, Glossopharyngeal,Nerves, Ninth Cranial,Ninth Cranial Nerves
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013650	Taste Buds	Small sensory organs which contain gustatory receptor cells, basal cells, and supporting cells. Taste buds in humans are found in the epithelia of the tongue, palate, and pharynx. They are innervated by the CHORDA TYMPANI NERVE (a branch of the facial nerve) and the GLOSSOPHARYNGEAL NERVE.	Bud, Taste,Buds, Taste,Taste Bud
D014867	Water	A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Hydrogen Oxide