Responses from parabrachial gustatory neurons in behaving rats

1990 ◽  
Vol 63 (4) ◽  
pp. 707-724 ◽  
Author(s):  
H. Nishijo ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Dimensional Space ◽  
Sucrose Concentration ◽  
Hierarchical Cluster ◽  
Multidimensional Analysis ◽  
Power Functions ◽  
Excitatory Activity ◽  
Neurophysiological Data ◽  
The Mean ◽  
Parabrachial Nuclei

1. The responses of a total of 70 single neurons were recorded from the parabrachial nuclei (PBN) in awake rats. In 59 neurons, sapid stimuli (0.5 ml) elicited significant taste responses. Of these 59 neurons, 10 also had significant responses to water. The mean spontaneous rate of the taste neurons was 13.4 +/- 6.9 (SD) spikes/s. Of the remaining 11 neurons, 9 responded significantly only to water; 2 had no significant responses to the standard fluid stimuli. 2. Based on the magnitude of their response to our four standard stimuli, the taste neurons were classified as follows: 42 NaCl-best, 14 sucrose-best, 2 citric acid-best, and 1 QHCl-best. Of these, 25 responded only to one of four sapid stimuli; 20 of these specific cells responded only to NaCl. All the remaining 34 neurons responded to two or more of the four sapid stimuli, with NaCl and sucrose responsiveness dominant. For the 59 taste neurons, the mean entropy for the absolute value of the responses was 0.68; for the excitatory activity alone, it was 0.58. 3. The mean responses to NaCl and sucrose concentration series increased monotonically. Except at the lowest concentration, responses to citric acid also increased monotonically, but with a lower slope. Mean responses to QHCl, however, remained stable or even decreased with increasing concentration. Thus the power functions for the NaCl and sucrose intensity-response series were higher than those of citric acid and QHCl. 4. A hierarchical cluster analysis of 59 parabrachial neurons suggested four different categories: NaCl-best, sucrose-best, citric acid-best, and QHCl-best. These categories were less evident in the two-dimensional space produced by multidimensional analysis, because the positions of NaCl- and sucrose-best neurons formed a continuum in which neural response profiles change successively from sucrose-specific to NaCl-specific. 5. The results were consistent with previous anatomic and neurophysiological data suggesting convergence in the medulla of sensory input from receptors in the nasoincisor ducts (NID) and on the anterior tongue (AT). Taste buds in the NID respond preferentially to sucrose, whereas those on the AT respond more to NaCl.(ABSTRACT TRUNCATED AT 400 WORDS)

Gustatory responses of neurons in the nucleus of the solitary tract of behaving rats

1991 ◽  
Vol 66 (4) ◽  
pp. 1232-1248 ◽  
Author(s):  
K. Nakamura ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Dimensional Space ◽  
Hierarchical Cluster ◽  
Stimulus Category ◽  
Solitary Tract ◽  
Spontaneous Rate ◽  
Taste Response ◽  
The Mean ◽  
Excitatory Responses ◽  
Gustatory Neurons

1. The activity of 117 single neurons was recorded in the rostral nucleus of the solitary tract (NST) and tested with each of four standard chemical stimuli [sucrose, NaCl, citric acid, and quinine HCl (QHCl)] and distilled water in awake, behaving rats. In 101 of these neurons, at least one sapid stimulus elicited a significant taste response. The mean spontaneous rate of the taste neurons was 4.1 +/- 5.8 (SD) spike/s. The mean response magnitudes were as follows: sucrose, 10.6 +/- 11.7; NaCl, 8.6 +/- 14.6; citric acid, 6.2 +/- 7.8; and QHCl, 2.4 +/- 6.6 spikes/s. 2. On the basis of their largest response, 42 taste neurons were classified as sucrose-best, 25 as NaCl-best, 30 as citric acid-best, and 4 as QHCl-best. The mean spontaneous rates for these categories were 4.9 +/- 6.2 for sucrose-best cells, 5.8 +/- 7.4 for NaCl-best, 1.6 +/- 2.0 for citric acid-best, and 5.8 +/- 6.0 spikes/s for QHCl-best. The spontaneous rate of the citric acid-best neurons was significantly lower than that of the other categories. 3. At the standard concentrations, 45 taste cells (44.6%) responded significantly to only one of the gustatory stimuli. Of the 30 acid-best neurons, 23 (76.7%) responded only to citric acid. For sucrose-best cells, specific sensitivity was less common (18/42, 42.9%), and for NaCl-best neurons, it was relatively uncommon (3/25, 12%). One of the 4 QHCl-best neurons was specific. In a concentration series, more than one-half of the 19 specific neurons tested responded to only one chemical at any strength. 4. The mean entropy for the excitatory responses of all gustatory neurons was 0.60. Citric acid-best cells showed the least breadth of responsiveness (0.49), sucrose-best cells were somewhat broader (0.56), but NaCl-best and QHCl-best cells were considerably less selective (0.77 and 0.79, respectively). Inhibition was observed infrequently and never reached the criterion for significance. 5. In the hierarchical cluster analysis, the four largest clusters segregated neurons primarily by best-stimulus category. The major exception to this was a group of sucrose-best neurons that also responded to NaCl and were grouped with the NaCl-best neurons. In a two-dimensional space, the specific taste neurons, those that responded to only one of the four standard sapid stimuli, remained in well-separated groups. These specific groups, however, were joined in a ring-like formation by other neurons that responded to more than one of the sapid stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Parabrachial gustatory neural activity during licking by rats

1991 ◽  
Vol 66 (3) ◽  
pp. 974-985 ◽  
Author(s):  
H. Nishijo ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Hierarchical Cluster ◽  
T Test ◽  
Fluid Delivery ◽  
The Mean ◽  
Parabrachial Nuclei ◽  
Hierarchical Cluster Analyses ◽  
Paired T Test

1. A total of 51 single neurons was recorded from the pontine parabrachial nuclei of three rats being given sapid stimuli either via intraoral infusions or during spontaneous licking behavior. In 46 neurons, sapid stimuli elicited significant taste responses; of these, 28 responded best to NaCl, 15 to sucrose, 2 to citric acid, and 1 to quinine HCl. The remaining five neurons responded significantly only to water. The mean spontaneous rate of taste neurons during the intraoral infusion and licking sessions was 11.1 +/- 1.1 and 10.8 +/- 1.2 (SE) spikes/s, respectively. 2. Of the 39 neurons tested during both licking and intraoral infusions, four responded significantly only to water via either route. The remaining 35 neurons responded significantly to at least some sapid stimuli. The best-stimulus categories remained the same regardless of the route of fluid delivery (24 NaCl best, 10 sucrose best, 1 citric acid best). When the rats were licking the stimuli, nine taste neurons responded significantly to only one sapid chemical [6 Na specific (Ns) and 3 sucrose specific (Ss)] but were more broadly tuned during intraoral infusions. Conversely, three taste neurons that responded specifically during intraoral infusions (3 Na specific) were not as specific when the animal licked the same fluids. 3. Thirty-five taste neurons were tested via both stimulus routes. These data were compared in three ways. First, for each neuron, the responses elicited during licking and intraoral infusions were compared for each of the four standard sapid stimuli. The Pearson correlation coefficients for the 35 taste neurons ranged from 0.9997 to 0.6785, with a mean at 0.953 +/- 0.012 (SE). The second comparison was between stimulus routes across chemicals. With the use of raw responses, the correlation coefficients for NaCl, sucrose, citric acid, and QHCl ranged from 0.925 to 0.778 (t test, P less than 0.0001). With the activity elicited by water subtracted (corrected responses), the correlation coefficients for NaCl, sucrose, citric acid, and QHCl were 0.900, 0.795, 0.369, and 0.211, respectively. The coefficient for QHCl was not significant (t test, P greater than 0.05). Finally, the mean responses to NaCl, sucrose, and citric acid delivered by both routes were compared and found not to differ (paired t test, P greater than 0.05). 4. In separate hierarchical cluster analyses for the licking and infusion data, the largest cluster in each contained all of the Na-best neurons and the next largest, all of the sucrose-best cells.(ABSTRACT TRUNCATED AT 400 WORDS)

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

scholarly journals Pseudosparse neural coding in the visual system of primates

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sidney R. Lehky ◽  
Keiji Tanaka ◽  
Anne B. Sereno
Keyword(s):  
Neural Coding ◽  
Macaque Monkey ◽  
Implicit Assumption ◽  
Data Set ◽  
Efficient Coding ◽  
Population Responses ◽  
Lateral Intraparietal Cortex ◽  
Neural Populations ◽  
Neurophysiological Data ◽  
The Mean

AbstractWhen measuring sparseness in neural populations as an indicator of efficient coding, an implicit assumption is that each stimulus activates a different random set of neurons. In other words, population responses to different stimuli are, on average, uncorrelated. Here we examine neurophysiological data from four lobes of macaque monkey cortex, including V1, V2, MT, anterior inferotemporal cortex, lateral intraparietal cortex, the frontal eye fields, and perirhinal cortex, to determine how correlated population responses are. We call the mean correlation the pseudosparseness index, because high pseudosparseness can mimic statistical properties of sparseness without being authentically sparse. In every data set we find high levels of pseudosparseness ranging from 0.59–0.98, substantially greater than the value of 0.00 for authentic sparseness. This was true for synthetic and natural stimuli, as well as for single-electrode and multielectrode data. A model indicates that a key variable producing high pseudosparseness is the standard deviation of spontaneous activity across the population. Consistently high values of pseudosparseness in the data demand reconsideration of the sparse coding literature as well as consideration of the degree to which authentic sparseness provides a useful framework for understanding neural coding in the cortex.

Differential Gurmarin Suppression of Sweet Taste Responses in Rat Solitary Nucleus Neurons

2003 ◽  
Vol 90 (2) ◽  
pp. 911-923 ◽  
Author(s):  
Christian H. Lemon ◽  
Toshiaki Imoto ◽  
David V. Smith
Keyword(s):  
Cluster Analysis ◽  
Sucrose Concentration ◽  
Hierarchical Cluster ◽  
Initial Response ◽  
Sweet Taste ◽  
Induced Response ◽  
Response Suppression ◽  
Response Profiles ◽  
Neuronal Type ◽  
Concentration Series

We examined the effect of the sweet transduction blocker gurmarin on taste responses recorded from neurons in the rat solitary nucleus (NST) to determine how gurmarin sensitivity is distributed across neuronal type. Initially, responses evoked by washing the anterior tongue and palate with 0.5 M sucrose, 0.1 M NaCl, 0.01 M HCl, and 0.01 M quinine-HCl were recorded from 35 neurons. For some cells, responses to a sucrose concentration series (0.01–1.0 M) or an array of sweet-tasting compounds were also measured. Gurmarin (10 μg/ml, 2–4 ml) was then applied to the tongue and palate. Stimuli were reapplied after 10–15 min. Neurons were segregated into groups based on similarities among their initial response profiles using hierarchical cluster analysis (HCA). Results indicated that sucrose responses recorded from neurons representative of each HCA-defined class were suppressed by gurmarin. However, a disproportionate percentage of cells in each group displayed sucrose responses that were substantially attenuated after gurmarin treatment. Postgurmarin sucrose responses recorded from neurons that composed 57% of class S, 40% of class N, and 33% of class H were suppressed by ≥50% relative to control. On average, attenuation was statistically significant only in class S and N neurons. Although the magnitude of gurmarin-induced response suppression did not differ across sucrose concentration, responses to different sweet-tasting compounds were differentially affected. Responses to NaCl, HCl, or quinine were not suppressed by gurmarin. Results suggest that information from gurmarin-sensitive and -insensitive receptor processes converges onto single NST neurons.

Sodium-deficient diet reduces gustatory activity in the nucleus of the solitary tract of behaving rats

1995 ◽  
Vol 269 (3) ◽  
pp. R647-R661 ◽  
Author(s):  
K. Nakamura ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Dietary Sodium ◽  
Solitary Tract ◽  
Deficient Diet ◽  
Dietary Condition ◽  
Response Profiles ◽  
The Mean ◽  
Response To Water ◽  
Gustatory Neurons ◽  
General Reduction

The activity of single taste neurons was recorded from the nucleus of the solitary tract before (n = 41) and after (n = 58) awake, behaving rats were switched to a sodium-free diet. During sodium deprivation, the spontaneous activity of the neurons increased (142%), but responses to water and sapid stimuli decreased. For all neurons in the sample, the mean response to water decreased to 72% of its predeprivation level, NaCl dropped to 53%, sucrose to 41%, citric acid to 68%, and quinine HCl to 84%. Despite the drop in magnitude, the response profiles of the taste neurons were not changed by the dietary condition. In the Na-replete state, 61% of the activity elicited by NaCl occurred in NaCl-best cells and 33% in sucrose-best neurons. In the depleted state, these values were 60 and 26%, respectively. Nevertheless, at the highest concentrations tested, deprivation did alter the relative responsiveness of the gustatory neurons to sucrose and NaCl in specific categories of neurons. Compared with acute preparations, dietary sodium deprivation in awake, behaving rats produced a more general reduction in the gustatory responses of neurons in the nucleus of the solitary tract. The largest reductions in elicited activity occurred for the "best stimulus" of a particular neuron, thus leading to smaller differences in response magnitude across stimuli, particularly at the highest concentrations tested.

scholarly journals Taste Interactions between Sweetness of Sucrose and Sourness of Citric and Tartaric Acid among Chinese and Danish Consumers

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1425
Author(s):  
Jonas Yde Junge ◽  
Anne Sjoerup Bertelsen ◽  
Line Ahm Mielby ◽  
Yan Zeng ◽  
Yuan-Xia Sun ◽  
...  
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Hierarchical Cluster ◽  
Taste Perception ◽  
Aqueous Samples ◽  
Chinese Consumers ◽  
Consumer Study ◽  
Agglomerative Hierarchical Cluster Analysis ◽  
Significant Difference ◽  
Sweetness Intensity

Tastes interact in almost every consumed food or beverage, yet many aspects of interactions, such as sweet-sour interactions, are not well understood. This study investigated the interaction between sweetness from sucrose and sourness from citric and tartaric acid, respectively. A cross-cultural consumer study was conducted in China (n = 120) and Denmark (n = 139), respectively. Participants evaluated six aqueous samples with no addition (control), sucrose, citric acid, tartaric acid, or a mixture of sucrose and citric acid or sucrose and tartaric acid. No significant difference was found between citric acid and tartaric acid in the suppression of sweetness intensity ratings of sucrose. Further, sucrose suppressed sourness intensity ratings of citric acid and tartaric acid similarly. Culture did not impact the suppression of sweetness intensity ratings of citric or tartaric acid, whereas it did influence sourness intensity ratings. While the Danish consumers showed similar suppression of sourness by both acids, the Chinese consumers were more susceptible towards the sourness suppression caused by sucrose in the tartaric acid-sucrose mixture compared to the citric acid-sucrose mixture. Agglomerative hierarchical cluster analysis revealed clusters of consumers with significant differences in sweetness intensity ratings and sourness intensity ratings. These results indicate that individual differences in taste perception might affect perception of sweet-sour taste interactions, at least in aqueous solutions.

scholarly journals Compositional Changes during the Fruit Development of Two Peach Cultivars Differing in Juice Acidity

1998 ◽  
Vol 123 (5) ◽  
pp. 770-775 ◽  
Author(s):  
Annick Moing ◽  
Laurence Svanella ◽  
Dominique Rolin ◽  
Monique Gaudillère ◽  
Jean-Pierre Gaudillère ◽  
...  
Keyword(s):  
Citric Acid ◽  
Fruit Development ◽  
Prunus Persica ◽  
Sucrose Concentration ◽  
Titratable Acidity ◽  
The Difference ◽  
Normal Acidity ◽  
Vacuolar Ph ◽  
C Nmr

Changes in metabolites were studied during the fruit development of two greenhouse grown peach [Prunus persica (L.) Batsch] cultivars with low acidity (`Jalousia') or normal acidity (`Fantasia'). Both cultivars had the same sucrose concentration in fruit mesocarp at maturity. In the fruit juice, pH was higher and titratable acidity was lower for `Jalousia' than for `Fantasia' from 80 days after bloom to maturity. At four different times during fruit development, in vivo 13C NMR spectroscopy was used to measure the vacuolar pH of fruit mesocarp. At 55 days after bloom, the vacuolar pH of fruit mesocarp was not significantly different between `Jalousia' and `Fantasia', whereas the juice pH was different between cultivars. The three major organic acids in fruit mesocarp were malic, citric, and quinic acids for both cultivars. Citric acid concentrations were similar in both cultivars until ≈85 days after bloom and then became significantly higher in `Fantasia'. A significantly higher concentration in malic acid in `Fantasia' than in `Jalousia' was observed from the end of the first growth phase to maturity. At maturity, `Fantasia' fruit had two and five times more malic and citric acid, respectively, than `Jalousia' fruit. The differences observed between `Jalousia' and `Fantasia' fruit for malic and citric acid concentrations accounted for the difference in titratable acidity. The differences in acid concentration appeared during the plateau between the two rapid growth phases of the fruit, i.e., far before the onset of maturation. The three major amino acids were asparagine, glutamic acid, and proline for both cultivars. Their concentration followed similar patterns in acid and low-acid fruit.

scholarly journals Assessment of Bacteriological Quality of Sheep Carcasses, Effect Level of 2.5% Citric Acid Spray on Bacterial Contamination of Meat, and Hygiene Practices of Workers in a Selected Abattoir in Debrezeit Town, Central Ethiopia

2021 ◽  
Vol 15 ◽  
pp. 117863022110375
Author(s):  
Derebew Aynewa ◽  
Zemichael Gizaw ◽  
Aklilu Feleke Haile
Keyword(s):  
Citric Acid ◽  
Bacterial Contamination ◽  
Total Coliform ◽  
Aerobic Bacteria ◽  
Bacteriological Quality ◽  
Before And After ◽  
Effect Level ◽  
The Mean ◽  
Structured Questionnaire

Background: Meat safety is important for public health. As part of the meat chain abattoirs are required to give attention to meat hygiene and safety in order to minimize hazards. Therefore, the current study was conducted to evaluate the bacteriological quality of sheep carcasses, knowledge and hygienic practices of workers in a selected abattoir and to determine the effect level of 2.5% citric acid spray on total coliforms and aerobic bacteria load of raw sheep carcasses surfaces. Methods: A cross-sectional study design with structured questionnaire and observational checklists observation were used. A systematic random sampling technique was employed. A total of 50 sample swabs (25 swabs before citric acid spray and 25 after citric acid spray) were randomly taken from brisket, flank and rump of sheep’s carcasses. Swabs were moistened with buffered peptone water (BPW) and samples were taken by rubbing 100 cm2 (10 cm × 10 cm) area delineated by sterile aluminum template. In addition, we administered a structured questionnaire and an observational checklists to assess knowledge and hygienic practices of workers. Bacteriological quality of sheep carcasses were analyzed using the methods described by the US bacteriological analytical manual. Results: The mean count for aerobic bacteria of the sheep carcasses before and after citric acid spray were 7.2log10 CFU/ml and 6.4log10 CFU/ml, respectively. The test results also showed that 21 (84%) and 15 (60%) of the swab samples were positive before and after spraying citric acid, respectively. The mean counts for coliform bacterial of the sheep carcasses before and after citric acid spray were 3.5log10 CFU/ml and 2.9log10 CFU/ml, respectively. The mean total aerobic and coliform counts before and after citric acid spray were significantly different ( P < .05). Regarding the hygiene condition of workers, all the respondents reported that they always washed their hands with soap before and after entering the slaughtering room and 23 (53.5%) of the workers reported that they used hot water. Thirty-one (72.1%) of the workers reported that they do not used soap to wash hands after visiting toilet. Thirty-five (81.4%) of the production workers did not wear mouth mask while handling and distribute meat/carcass. On the other hand, all of the workers wore capes, gowns and boots at the time of the observation and only 18 (18.6%) of the production workers wore gloves at the time of the survey. Conclusion: The current study revealed that significant proportion of sheep carcasses were positive for total aerobic bacteria and total coliform. Moreover, the study also showed that spraying of sheep carcasses with 2.5% citric acid significantly reduced the total coliform and aerobic counts. However, we did not assessed how much spray results to this effect. Therefore, we recommended further studies to determine how much spray of 2.5% citric acid significantly reduce bacterial contamination of sheep carcasses. In addition, the abattoir has to follow the food hazard analysis critical control point (HACCP) system to minimize meat contamination during harvesting and processing. The abattoir has to also implement strict operation laws to improve hygiene conditions of the workers. In addition, the abattoir can minimize meat contamination using 2.5% citric acid as a decontaminant.

scholarly journals Approximation and Analytical Studies of Inter-clustering Performances of Space-Filling Curves

2003 ◽  
Vol DMTCS Proceedings vol. AC,... (Proceedings) ◽  
Author(s):  
Ho-Kwok Dai ◽  
Hung-Chi Su
Keyword(s):  
Random Walk ◽  
Dimensional Space ◽  
Hilbert Curve ◽  
Space Filling ◽  
Space Filling Curve ◽  
Space Filling Curves ◽  
Order Curve ◽  
Cluster Distance ◽  
The Mean ◽  
Curve Family

International audience A discrete space-filling curve provides a linear traversal/indexing of a multi-dimensional grid space.This paper presents an application of random walk to the study of inter-clustering of space-filling curves and an analytical study on the inter-clustering performances of 2-dimensional Hilbert and z-order curve families.Two underlying measures are employed: the mean inter-cluster distance over all inter-cluster gaps and the mean total inter-cluster distance over all subgrids.We show how approximating the mean inter-cluster distance statistics of continuous multi-dimensional space-filling curves fits into the formalism of random walk, and derive the exact formulas for the two statistics for both curve families.The excellent agreement in the approximate and true mean inter-cluster distance statistics suggests that the random walk may furnish an effective model to develop approximations to clustering and locality statistics for space-filling curves.Based upon the analytical results, the asymptotic comparisons indicate that z-order curve family performs better than Hilbert curve family with respect to both statistics.

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