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K Tonosaki

Publications and source records attributed to K Tonosaki.

At least 37 records · Page 2Linked to original sources
PubMed1992

Cross-adapted salt responses in the mouse taste cell.

The exact nature of taste adaptation is not known. Intracellular recordings from taste receptor cells are appropriate to clarify cellular adaptation properties. I approached the study of the sugar and salt receptor mechanisms of mammalian taste cells with cross-adaptation experiments. Sucrose pre-adaptation suppresses the cross-adaptation responses to salts. The results show that the taste adaptation is located in the taste receptor cell.

Adaptation, Physiological↗
PubMed1992

Adaptation effect of sucrose on the salt taste response.

1. Intracellular recordings from mouse taste receptor cells were made to study cellular adaptation properties. 2. The sugar and salt receptor mechanisms of mammalian taste cells were investigated with cross-adaptation experiments. 3. The responding of taste cells to sucrose as well as to NaCl does not contradict the independency of their binding mechanisms. 4. With a mixture of sucrose and NaCl, different adsorption mechanisms are observed. 5. From these observations, it was concluded that adaptation occurs in the taste receptor cell.

Adaptation, Physiological↗
PubMed1989

Cross-adapted sugar responses in the mouse taste cell.

1. Intracellular recordings of mouse taste cell responses were made using a glass micro-electrode filled with Procion yellow dye solution. 2. Six sugars (sucrose, maltose, lactose, glucose, galactose and fructose) produced the depolarization responses. 3. Gustatory cross adaptation between sugars was determined. When the taste cell was pre-adapted with one of the six sugars, the other five sugars, cross adapted, produced depolarization, hyperpolarization or null responses. 4. From these observations, it is suggested that there are multiple sugar receptor sites on the receptor membrane of the mouse taste cell.

Adaptation, Physiological↗
PubMed1989

Sugar best single chorda tympani nerve fiber responses to various sugar stimuli in rat and hamster.

1. Sugar best single chorda tympani nerve fiber of rat and hamster were tested with six sugars. 2. Fibers were selected for this experiment, only if they responded to 1.0 M sucrose or 1.0 M maltose and they responded poorly to 0.1 M NaCl. 3. In rat, some single fibers gave larger responses to maltose than to sucrose, while in hamster nearly all nerve fibers responded best to sucrose. 4. The order of effectiveness of sugars was maltose greater than fructose greater than or equal to lactose greater than sucrose greater than glucose greater than galactose in rat and sucrose greater than fructose greater than or equal to glucose greater than or equal to galactose greater than maltose greater than lactose in hamster.

Animals↗
PubMed1989

Amiloride does not block taste transduction in the mouse (Slc:ICR).

1. The receptor potential of the mouse taste cell was recorded with an intracellular microelectrode while taste stimuli were applied to the tongue surface of the anesthetized mouse. 2. A membrane depolarization accompanied by an increase in membrane resistance was observed after a sucrose stimulus. 3. A sodium-chloride stimulus initiated a membrane depolarization accompanied by a decrease in membrane resistance. 4. Amiloride elicits a depolarization of the membrane and is accompanied by an increase in membrane resistance. 5. Pre-adapting the tongue to amiloride, which is known as a potent sodium channel blocker, did not alter the responses to sodium-chloride and other taste stimuli.

Amiloride↗
PubMed1988

Voltage- and current-clamp recordings of the receptor potential in mouse taste cell.

Intracellular recordings were obtained using the current-clamp and voltage-clamp techniques. When the taste cell membrane was voltage-clamped, the sucrose stimulus induced an inward current accompanied by a membrane resistance increase while the NaCl stimulus induced an inward current accompanied by a membrane resistance decrease. These phenomena indicated that sucrose and NaCl have quite a different generation mechanism of taste responses.

Animals↗
PubMed1988

Cyclic nucleotides may mediate taste transduction.

Taste stimulus adsorption is believed to occur at the taste cell microvillous membrane. But due to technical difficulties of inserting glass electrodes into the mammalian taste cell, little is known about the mechanisms of taste transduction. Reliable intracellular recordings are necessary to determine the characteristics of taste cells. This has been accomplished previously in the mouse and is reported here. Recent experiments indicated that cyclic nucleotides can act on the inner surface of the membranes of a variety of cells to alter their ion-channel activity, and these substances might act as intracellular transmitters in taste cells. But tight junctions found at the apical membrane of mammalian taste cells do not allow stimuli to enter the taste bud, making it difficult to alter the environment of the taste cell by perfusing with chemical solutions. Here we report that cyclic AMP, cyclic GMP, EGTA or tetraethyl-ammonium electrophoretically injected into the mouse taste cell induce membrane depolarization and increased membrane resistance. These results suggest that a cyclic nucleotide enzymatic cascade, modulated by calcium ions, may mediate the potassium permeability that controls taste, in a way analogous to visual and olfactory transduction.

Animals↗
PubMed1985

Olfactory receptor cell responses of pigeon to some odors.

A preparation has been developed in the pigeon which allows recording of the electrical activity from an olfactory nerve twig containing the nonmyelinated axons of a small group of olfactory receptor cells. The pigeon's response to n-amylacetate is vigorous and stable, like that of other air-breathing animals. Responses in the olfactory receptor cells in the pigeon increased in magnitude with increase in the odor concentration. An olfactory nerve twig produced a different magnitude of responses to the various odor stimuli. When an odor stimulation was applied to the olfactory mucosa, the two different olfactory nerve twigs which were separated from the same olfactory nerve bundle produced a different magnitude of responses. The differences may be dependent on several factors.

Animals↗
PubMed1985

Responsiveness of the olfactory receptor cells in dog to some odors.

A preparation has been developed in the dog which allows recording the electrical activity from an olfactory nerve twig containing the axons of a small group of olfactory receptor cells. The dog's response to n-pentyl acetate is vigorous and stable, like that of other air-breathing animals. The dog's response magnitude dependence on the nasal flow rate was noticeable for n-pentyl acetates, but not so great as for n-butyric acid. The response to n-butyric acid strongly depends on the nasal flow. The start of the nasal air flow caused an increase of neural activity, which is called flow response. The results show that the nasal flow rate is a very important factor which determines the response to odors. Methyl p-hydroxybenzoate is known as a dog's pheromone, however, this odor caused the feeble response in the electrical activity of the dog's olfactory receptor cells. The differences may be dependent on several factors.

Animals↗
PubMed1985

The effect of some drugs on the mitral cell odor-evoked responses in the gecko olfactory bulb.

The activity of odor-evoked olfactory mitral cell response of the gecko was recorded extracellularly by glass microelectrodes. The activities of the mitral cell observed during the presentation of the odor (n-amyl acetate) could be described as excitation, suppression or zero. The present experiments were undertaken to study the neural activities of the mitral cell in the olfactory bulb by perfusion application of some drugs (cobalt chloride, carnosine, norepinephrine, GABA and D-L-homocysteate) on the olfactory bulb surface or iontophoretic application of some drugs (carnosine, norepinephrine, GABA and D-L-homocysteate) to the glomerulus and the external plexiform layer to change the physiological environment. The effect of the drugs suggested that the synaptic neurons on the mitral cell have different chemical characteristics.

Action Potentials↗
PubMed1984

The mouse taste cell response to five sugar stimuli.

Intracellular recordings of mouse taste cell responses were made using glass microelectrodes filled with procion yellow dye solution. Only responses recorded from taste buds with fluorescent cells, as observed in subsequent histological preparations, were used in this study. The mouse taste cell depolarizes when stimulated with sucrose and is accompanied by either a resistance increase or no change. On the other hand, a NaCl stimulus produces a depolarization, hyperpolarization or null response and is accompanied by either a membrane resistance decrease or no change. Four sugars other than sucrose (maltose, fructose, glucose and lactose) produced the depolarization or null responses and were accompanied by an increase or no change in membrane resistance. From the above observations, it is suggested that each taste cell produces its own characteristic response profiles and membrane resistance changes for the five sugars and NaCl tested.

Animals↗
PubMed1984

Intracellular taste cell responses of mouse.

Intracellular recordings of membrane potentials of taste cells in mouse taste bud were made using a glass microelectrode filled with procion yellow dye solution. The recorded taste cell was injected with procion yellow dye solution. Each taste bud preparation was observed under a fluorescence microscope and if a stained taste cell was not found in the taste bud preparation, the responses were negated. Sucrose produced a depolarization response and the response was accompanied by resistance increase, whereas NaCl produced a depolarization, hyperpolarization or null response and the response was accompanied by resistance decrease in all cases. Most mouse taste cells showed a multiple sensitivity to four fundamental taste stimuli.

Animals↗
PubMed1982

Gustatory neural response in the mouse.

Gustatory responses from the mouse chorda tympani nerve were tested with various chemical solutions. Magnitudes of integrated chorda tympani responses to the 4 basic taste stimuli were greater in the order of HCl, sucrose, NaCl and quinine-HCl. Sucrose was the most effective sugar tested, while NaCl was the least effective salt, but divalent chloride salts were prominently effective stimulants. Many of single chorda tympani fibers responded specifically to one or two of the 4 basic taste stimuli. Single fibers sampled were classified into the following 5 types: sweet-type, Na-type, Ca-Mg-type, acid-type and quinine-type.

Animals↗
PubMed1982

The olfactory bulb mitral cell responses in the gecko as studied by intracellular recording.

The mitral cell odor-induced intracellular responses and the accompanying membrane resistance changes were studied in the gecko olfactory bulb. The mitral cells responded to odor either with depolarization or with hyperpolarization. The depolarization responses with hyperpolarization. The depolarization responses were accompanied by a resistance decrease. The hyperpolarization responses were accompanied by a resistance increase. The responses were enhanced by hyperpolarization and suppressed by depolarization of the membrane current. Two types of mitral cells were identified by procion yellow dye injection.

Animals↗