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Biomedical subjects

M Funakoshi

Publications and source records attributed to M Funakoshi.

At least 73 records · Page 4Linked to original sources
PubMed1984

Qualitative discrimination of gustatory stimuli in three different strains of mice.

Qualitative similarities and differences among various taste stimuli were examined by comparing the generalization patterns of a conditioned aversion from single chemicals to other compounds in 3 different strains of mice (BALB, C3H and C57BL mice). It was observed as a common characteristic in all 3 strains of mice that generalization gradients among sugars and saccharin Na appeared in the order sucrose--saccharin Na--fructose--glucose--maltose, in which the closer stimuli generalized more strongly to each other. Strain differences were found in sensitivities to D-phenylalanine and L-proline, which generalized to sugars and saccharin Na in C57BL mice, but not in BALB and C3H mice. These strain differences correspond quite well to those previously observed in the responses of single chorda tympani fibers to these amino acids in the 3 strains of mice. A hierarchical cluster analysis and a multidimensional scaling analysis showed that 15 compounds including the 4 basic taste stimuli (sucrose, NaCl, HCl and quinine-HCl) were classified into 7 different groups according to their behavioral similarities and some amino acids were not grouped with any of the 4 basic taste stimuli in the 3 strains of mice. These results suggest the possibility that mice perceive tastes of these amino acids in a way different from human taste primaries.

Animals↗
PubMed1984

Gustatory neural responses in three different strains of mice.

Taste sensitivity in mice and its strain variation were studied by examining integrated responses and single fiber discharges of the chorda tympani nerve to various taste stimuli in the 3 different strains of mice (BALB, C3H and C57BL mice). A comparison among integrated responses of the 3 strains demonstrated that C57BL mice possess the highest sensitivity to sucrose and the lowest to acids, whereas the opposite is true for BALB mice. These 3 strains of mice commonly possess higher sensitivity to divalent chloride salts than to NaCl. Measures of the breadth of responsiveness showed that single fibers of all 3 strains of mice are relatively more narrowly tuned to taste stimuli than those of rats and hamsters, although the specificity of fibers tends to be greater in the order of C57BL greater than C3H greater than BALB mice. A cluster analysis of fibers demonstrated that two distinct fiber types, a sweet- and Na-type, commonly exist in all 3 strains of mice. The most clear strain difference was found in the sensitivity to D-phenylalanine, which produced good responses in 'sweet-type' fibers of C57BL mice but not in those of C3H and BALB mice. This suggests the possibility that D-phenylalanine has a taste to C57BL mice that is similar to that of sucrose and that it tastes different to C3H and BALB mice.

Animals↗
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↗
PubMed1984

Effects of biofeedback training on tonic masticatory neck reflex: a case report.

Biofeedback training to reduce muscle tension lowered not only the spontaneous activity but also the tonic neck reflex in the jaw closing muscles. Tolperisone-HCl, which may inhibit the gamma system, inhibited the tonic masticatory neck reflex, but did not reduce the patient's spontaneous activity of the jaw closing muscles in this case. Biofeedback training may be considered to reduce the gamma as well as alpha motor systems.

Biofeedback, Psychology↗
PubMed1984

Transfusion-mediated spread of the human T-cell leukemia virus in chronic hemodialysis patients in a heavily endemic area, Nagasaki.

The incidence of anti-adult T-cell leukemia-associated antigens (ATLA) was surveyed in 134 patients under chronic hemodialysis in the Nagasaki area, as well as 4708 blood donors resident in the same area as controls: 23 patients (17%) and 201 donors (4.3%) were positive for anti-ATLA antibody. All seropositive patients were found to have had a positive history of blood transfusions. Seroconversions were confirmed in 9 cases, all of them after initiation of transfusions. In total, 216 units of blood were transfused in 7 seroconverted patients, and this is consistent with the estimated rate of anti-ATLA antibody-positive donor blood supplied by the Red Cross Nagasaki Blood Center (5%).

Adult↗
PubMed1983

Relations between the spontaneous firing rate and taste responsiveness of the dog cortical neurons.

The breadth of responsiveness and the spontaneous discharge rates of dog cortical neurons to 4 taste stimuli (NaCl, tartaric acid, sucrose and quinine-HCl) were examined and compared to thalamic neurons. Spontaneous rates were higher in the cortex, and there was a smaller breadth of responsiveness. There were common tendencies observed in both thalamus and cortex; more narrowly tuned taste neurons and neurons having inhibitory responses had higher spontaneous rates. However, as shown by across-neuron correlations, the ability of cortical neurons to discriminate among the 4 tastes was less influenced by the level of spontaneous activity than thalamic neurons.

Animals↗
PubMed1983

Effects of androgens on the activity of steroid-metabolizing enzymes in the murine submaxillary gland.

Effects of androgens on the activity of androgen-metabolizing enzymes have been investigated in the murine submaxillary gland. 5 alpha-reductase activity is androgen-dependent, and 17 beta-hydroxysteroid dehydrogenase activity is androgen-resistant. The level and androgen-responsiveness of 5 alpha-reductase in the murine submaxillary gland are not imprinted during the neonatal period by testicular androgens. Circulating androgen may have a cumulative effect on androgen response of 5 alpha-reductase.

17-Hydroxysteroid Dehydrogenases↗
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

Relationships between spontaneous discharge rates and taste responses of the dog thalamic neurons.

Response characteristics to the 4 taste stimuli (NaC1, tartaric acid, sucrose and quinine-HCl) and spontaneous discharge rates of taste neurons in the dog thalamus were examined. Response patterns of 72 thalamic neurons were somewhat complex, involving excitation (on type, on-off type and off type) and inhibition (short-term type and long-term type). A comparison among the responses to the 4 taste stimuli renders low response discharge rates and a high incidence of inhibitory responses to quinine-HCl. Measuring of the breadth of responsiveness showed that the thalamic taste neurons have varying sensitivities to the 4 taste stimuli and neurons responding best to quinine-HCl were more broadly tuned than those to each of the other 3 stimuli. These neurons also have varying spontaneous discharge rates and showed some relationship between the spontaneous rates and responses to taste stimuli. Neurons which showed inhibitory responses to stimuli have relatively high spontaneous rates. Neurons with higher spontaneous rates tend to be more narrowly tuned to the 4 taste stimuli. These relationships appeared not only as a general tendency of all the thalamic neurons but also as a characteristic of each of the 3 individual neurons which changed the spontaneous rates and breadth of responsiveness during long time recordings of neural discharges.

Action Potentials↗
PubMed1982

Responsiveness of dog thalamic neurons to taste stimulation of various tongue regions.

Receptive fields of single thalamic taste neurons in dogs were studied by examining responses to stimuli representing the four basic taste qualities applied to five different regions on the tongue surface. Twenty single thalamic units responded to taste stimulation of the tongue ipsilateral to the recording site were classified into three types according to characteristics of their receptive fields. In 11 out of 20 units, the location and the size of the receptive field and the most sensitive region in the receptive field did not vary among their effective taste stimuli (type A units). In 5 units, the location and the size of the receptive field varied with taste stimulus, although the most sensitive region was common to the stimuli (type B units). In the remaining 4 units, the most sensitive region varied with taste stimulus (type C units).

Afferent Pathways↗
PubMed1981

Dynamic-static sensitivity of rat chorda tympani fibers to anodal current applied to the tongue.

Responses of rat single chorda tympani fibers to anodal current of varying rise rates and current intensities applied to the tongue were examined. Thirteen out of fifteen chorda tympani fibers were sensitive to both rate of current rise and current intensity. However, sensitivities to these two stimulus parameters were different among 13 fibers. The remaining two fibers were not sensitive to the rate of current rise, but sensitive to current intensity. It was suggested that sensitivity to the rate of current rise was independent from that to current intensity.

Animals↗