Intracellular pH Modulates Taste Receptor Cell Volume and the Phasic Part of the Chorda Tympani Response to Acids. Export

@article{citeulike:485659, abstract = {The relationship between cell volume and the neural response to acidic stimuli was investigated by simultaneous measurements of intracellular pH (pH(i)) and cell volume in polarized fungiform taste receptor cells (TRCs) using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) in vitro and by rat chorda tympani (CT) nerve recordings in vivo. CT responses to HCl and CO(2) were recorded in the presence of 1 M mannitol and specific probes for filamentous (F) actin (phalloidin) and monomeric (G) actin (cytochalasin B) under lingual voltage clamp. Acidic stimuli reversibly decrease TRC pH(i) and cell volume. In isolated TRCs F-actin and G-actin were labeled with rhodamine phalloidin and bovine pancreatic deoxyribonuclease-1 conjugated with Alexa Fluor 488, respectively. A decrease in pH(i) shifted the equilibrium from F-actin to G-actin. Treatment with phalloidin or cytochalasin B attenuated the magnitude of the pH(i)-induced decrease in TRC volume. The phasic part of the CT response to HCl or CO(2) was significantly decreased by preshrinking TRCs with hypertonic mannitol and lingual application of 1.2 mM phalloidin or 20 muM cytochalasin B with no effect on the tonic part of the CT response. In TRCs first treated with cytochalasin B, the decrease in the magnitude of the phasic response to acidic stimuli was reversed by phalloidin treatment. The pH(i)-induced decrease in TRC volume induced a flufenamic acid-sensitive nonselective basolateral cation conductance. Channel activity was enhanced at positive lingual clamp voltages. Lingual application of flufenamic acid decreased the magnitude of the phasic part of the CT response to HCl and CO(2). Flufenamic acid and hypertonic mannitol were additive in inhibiting the phasic response. We conclude that a decrease in pH(i) induces TRC shrinkage through its effect on the actin cytoskeleton and activates a flufenamic acid-sensitive basolateral cation conductance that is involved in eliciting the phasic part of the CT response to acidic stimuli.}, address = {Correspondence to Vijay Lyall: vlyall@hsc.vcu.edu.}, author = {Lyall, V. and Pasley, H. and Phan, T. H. and Mummalaneni, S. and Heck, G. L. and Vinnikova, A. K. and Desimone, J. A.}, citeulike-article-id = {485659}, citeulike-linkout-0 = {http://dx.doi.org/10.1085/jgp.200509384}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/16380442}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=16380442}, doi = {10.1085/jgp.200509384}, issn = {0022-1295}, journal = {J Gen Physiol}, keywords = {ph, taste, trc}, month = {January}, number = {1}, pages = {15--34}, posted-at = {2006-01-30 07:17:15}, priority = {2}, title = {Intracellular pH Modulates Taste Receptor Cell Volume and the Phasic Part of the Chorda Tympani Response to Acids.}, url = {http://dx.doi.org/10.1085/jgp.200509384}, volume = {127}, year = {2006} }

TY - JOUR ID - citeulike:485659 L3 - citeulike-article-id:485659 N2 - The relationship between cell volume and the neural response to acidic stimuli was investigated by simultaneous measurements of intracellular pH (pH(i)) and cell volume in polarized fungiform taste receptor cells (TRCs) using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) in vitro and by rat chorda tympani (CT) nerve recordings in vivo. CT responses to HCl and CO(2) were recorded in the presence of 1 M mannitol and specific probes for filamentous (F) actin (phalloidin) and monomeric (G) actin (cytochalasin B) under lingual voltage clamp. Acidic stimuli reversibly decrease TRC pH(i) and cell volume. In isolated TRCs F-actin and G-actin were labeled with rhodamine phalloidin and bovine pancreatic deoxyribonuclease-1 conjugated with Alexa Fluor 488, respectively. A decrease in pH(i) shifted the equilibrium from F-actin to G-actin. Treatment with phalloidin or cytochalasin B attenuated the magnitude of the pH(i)-induced decrease in TRC volume. The phasic part of the CT response to HCl or CO(2) was significantly decreased by preshrinking TRCs with hypertonic mannitol and lingual application of 1.2 mM phalloidin or 20 muM cytochalasin B with no effect on the tonic part of the CT response. In TRCs first treated with cytochalasin B, the decrease in the magnitude of the phasic response to acidic stimuli was reversed by phalloidin treatment. The pH(i)-induced decrease in TRC volume induced a flufenamic acid-sensitive nonselective basolateral cation conductance. Channel activity was enhanced at positive lingual clamp voltages. Lingual application of flufenamic acid decreased the magnitude of the phasic part of the CT response to HCl and CO(2). Flufenamic acid and hypertonic mannitol were additive in inhibiting the phasic response. We conclude that a decrease in pH(i) induces TRC shrinkage through its effect on the actin cytoskeleton and activates a flufenamic acid-sensitive basolateral cation conductance that is involved in eliciting the phasic part of the CT response to acidic stimuli. IS - 1 JF - J Gen Physiol SN - 0022-1295 AD - Correspondence to Vijay Lyall: vlyall@hsc.vcu.edu. EP - 34 TI - Intracellular pH Modulates Taste Receptor Cell Volume and the Phasic Part of the Chorda Tympani Response to Acids. VL - 127 SP - 15 KW - ph KW - taste KW - trc AU - Lyall, V AU - Pasley, H AU - Phan, TH AU - Mummalaneni, S AU - Heck, GL AU - Vinnikova, AK AU - Desimone, JA PY - 2006/01// UR - http://dx.doi.org/10.1085/jgp.200509384 ER -