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Biomedical subjects

I J Miller

Publications and source records attributed to I J Miller.

30 records · Page 2Linked to original sources
PubMed1986

Variation in human fungiform taste bud densities among regions and subjects.

Taste sensitivity is known to vary among regions of the tongue and between subjects. The distribution of taste buds on the human tongue is examined in this report to determine if interregional and intersubject variation of taste bud density might account for some of the variation in human taste sensitivity. The subjects were ten males, aged 22-80 years, who died from acute trauma or an acute cardiovascular episode. Specimens were obtained as anatomical gifts or from autopsy. A sample of tissue about 1 cm2 was taken from the tongue tip and midlateral region; frozen sections were prepared for light microscopy; and serial sections were examined by light microscopy to count the taste buds. The average taste bud (tb) density on the tongue tip was 116 tb/cm2 with a range from 3.6 to 514 among subjects. The number of gustatory papillae on the tip averaged 24.5 papillae/cm2 with a range from 2.4 to 80. Taste bud density in the midregion averaged 25.2 tb/cm2 (range: 0-85.9), and the mean number of gustatory papillae was 8.25/cm2 (range: 0-28). The mean number of taste buds per papilla was 3.8 +/- 2.2 (s.d.) on the tip and 2.6 +/- 1.5 (s.d.) on the midregion. Subjects with the highest taste bud densities on the tip also had the highest densities in the midregion and the highest number of taste buds per papilla. Taste bud density was 4.6 times higher on the tip than the midregion, which probably accounts for some of the regional difference in taste sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Impact of renal donation. Long-term clinical and biochemical follow-up of living donors in a single center.

Forty-six renal donors who responded to a questionnaire and two additional donors with nephrotic syndrome and renal insufficiency were studied. The mean age was 46 +/- 2.0 years (mean +/- SE). Duration of follow-up was 6 +/- 0.5 years. Serum creatinine levels increased from 1.0 +/- 0.03 mg/dl before donation to 1.2 +/- 0.04 mg/dl at follow-up. The incidence of proteinuria (more than 150 mg over 24 hours) was 39 percent. The serum creatinine level was 1.0 +/- 0.08 mg/dl and 1.2 +/- 0.06 mg/dl in the proteinuric and nonproteinuric groups, respectively. The incidence of hypertension was 31 percent with a serum creatinine level of 1.1 +/- 0.11 mg/dl and 1.2 +/- 0.07 mg/dl in the hypertensive and normotensive groups, respectively. One patient with nephrotic syndrome had proliferative glomerulonephritis. It is concluded that renal donation is associated with a minimal but statistically significant increment in serum creatinine levels. The incidence of mild hypertension and proteinuria is increased, but impact on renal function is minimal as assessed by serum creatinine determination.

Adolescent↗
PubMed1984

Quantitative taste bud distribution in the hamster.

The distribution of taste buds was examined in hamsters to reveal the sources of convergent neural activity on taste neurons of the medulla and pons. A total of 723 taste buds was found in adult animals. Fungiform papillae contained 130 taste buds (18%). A single vallate papilla had 168 taste buds (23%). There were 230 taste buds (32%) located on bilateral foliate papillae. The palate contained 100 taste buds (14%) divided among the soft palate (88, 12%) and the incisal papilla (12, 2%). On the epiglottis and adjacent region of the esophagus were found 70 taste buds (10%). About 10 taste buds each were located on the buccal wall (1.4%), while the remaining 5 taste buds were found on the sublingual organ. Conclusions about information processing in central neurons of the gustatory system must reflect knowledge of diverse receptor populations and their interactions.

Animals↗
PubMed1982

Localization of the motor neurons to the tensor tympani muscle.

The localization of the motor neurons to the tensor tympani (TT) muscle was studied using the method of retrograde transport of horseradish peroxidase (HRP). After intramuscular injections of HRP, specifically labeled neurons were found in the ventral, parvocellular portion of the trigeminal motor nucleus. These cells had a medial relation to the rootlets of the trigeminal nerve and, rostrally, to the lateral lemniscus. The results are compared to those of other investigators and a generalization is suggested for the localization of these neurons which allows for species variation. Other incidental findings are also discussed.

Animals↗
PubMed1979

Taste responses to deuterium oxide.

Substitution of deuterium oxide (D2O) as the solvent in taste stimuli elicits neural responses which differ from ordinary water (H2O). Previous reports have shown that D2O is toxic to many animals and rats avoid drinking it when offered H2O simultaneously. In the current study, summated responses were recorded from the chorda tympani nerves of rats after NaCl, KCl, sucrose and quinine were applied to the tongue in solutions of either D2O or H2O. Both solvents were used as the adapting or rinse solution in separate series. On tongues adapted to H2O, D2O elicited mean responses which were equivalent to 29% of the response to 0.1 M NaCl. The threshold concentration of D2O in H2O was between 25% and 50%. Solutes in D2O yielded responses which were greater than corresponding solutions of H2O when adapting rinse was H2O. Adaptation to D2O diminished the responses to D2O solutions of NaCl, KCl and sucrose but not quinine. This observation suggests that some portion of the augmented response to stimuli in D2O is due to the solvent itself. The taste of water has been examined by both electrophysiological methods and by behavior, but none of the mechanisms espoused for its effect seem adequate to explain the response to D2O. Water structure at the interface between molecular components of the cell membrane and the bulk phase of the surrounding medium is considered as a locus for disparity in the taste responses to D2O and H2O in the rat.

Animals↗
PubMed1975

Spatial distribution of rat fungiform papillae.

The objective of this study was to determine the spatial distribution of fungiform papillae on the rat's tongue. Since each fungiform papilla in the rat has a single taste bud, the spatial distribution of fungiform papillae is equivalent to the location of taste buds on the anterior tongue. A mean total number of 187 fungiform papillae per tongue were found which were about equally divided between the two lateral halves of the tongue. Over 50% of the total number of fungiform papillae were located on the tongue tip for an average density of 3.4 papillae/mm2,while the dorsal surface of the tongue had an average density of 1.3 papillae/mm2 of tongue surface. Papillae were absent on the dorsal midline, but a paracentral line of papillae running from anterior to posterior was a consistent finding. Though not identical, the distribution of papillae was essentially the same on different tongues. The functional significance of the papilla distribution is not understood, but electrophysiological experiments show evidence of neural interaction of papillae which are clustered together. The distribution of papillae and the distribution of nerve fibers which innervate them must be evaluated together in order to appreciate the significance of the distribution of fungiform papillae and their associated taste buds.

Animals↗
PubMed1971

Peripheral interactions among single papilla inputs to gustatory nerve fibers.

Recordings were made from single fibers of the rat chorda tympani nerve while the peripheral receptor fields were mapped using a stimulator developed to stimulate single fungiform papillae which in the rat contain a solitary taste bud. The results indicate that several fungiform papillae may supply input to a single fiber, and the most sensitive papilla of these provided, on the average, about one-half of the response of that fiber to stimulation of the entire tongue. The magnitude of the response to each concentration of stimulus and the shape of the concentration-response curves differ among papillae innervated by the same fiber. If one of the papillae supplying input to the fiber was stimulated individually with NaCl solution, application of this stimulus to the tongue surface surrounding the isolated papilla resulted in enhancement of the fiber response. If the papilla was stimulated with NaCl and potassium benzoate solution was applied to the surround, a depression of the response occurred. The excitatory input of the cationic stimuli and the depressing influence of the anionic stimuli interacted to determine the resultant steady-state impulse frequency of the single afferent fiber. A hypothetical model involving the summation of generator currents along the unmyelinated terminals of the single afferent neuron is presented as a speculative explanation of the integration of inputs from several receptors innervated by the same single fiber.

Action Potentials↗