bluuebunny/crossref_metadata_2025 huggingface dataset:
Olfactory Bulb and Tract and Temporal Lobe Volumes: Normative Data across Decadesa
Authors: YOUSEM DAVID M. , GECKLE RENA J. , BILKER WARREN B. , DOTY RICHARD L.
Published: February 2006

ABSTRACT: The sense of smell shows a diminution with age as measured by the University of Pennsylvania Smell Identification Test (UPSIT). To ascertain whether the volumes of the olfactory bulbs and tracts (OBTs) and the temporal lobes (TL) declined in parallel to smell function, we examined 36 individuals from ages 22 to 78 who did not complain of any loss of the sense of smell using magnetic resonance (MR) imaging. The OBT volumes showed an initial increase to the 4th decade of life and then a decrease with increasing age, while the trend in TL volume was not as dramatic. There was no correlation between OBT or TL volumes with unilateral or total UPSIT scores. The normative data by decades can be used to assess the OBTs of cohorts of patients with neurodegenerative disorders that affect olfaction.
Understanding Neural Interactions in Learning and Memory Using Functional Neuroimaging
Authors: McINTOSH ANTHONY RANDAL
Published: February 2006

ABSTRACT:Neuroimaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) provide a unique opportunity to explore activity across the entire human brain in many different behaviors. An important additional feature is the ability to examine interacting neural systems using methods that focus on the covariances of activity. Two of these methods, partial least squares and structural equation modeling, are presented with specific examples. Shifting prefrontal and limbic interactions were observed in a working memory task for faces. In an episodic memory retrieval study, the activity of right prefrontal cortex was related to either memory search or successful retrieval depending on its interactions with other brain regions. This latter observation implies that regional activity must be evaluated within theneural contextin which it occurs. The general hypothesis that learning and memory are emergent properties of network interactions is discussed, emphasizing that a region can play a different role across many functions and that role is governed by its interactions with anatomically related regions.
Human Brain Function during Odor Encoding and Recognition: A PET Activation Studya
Authors: DADE L. A. , JONES‐GOTMAN M. , ZATORRE R. J. , EVANS A. C.
Published: February 2006

ABSTRACT: In previous positron emission tomography (PET) studies we have shown significant regional cerebral blood flow (rCBF) increases during olfactory stimulation: unilaterally in the right orbitofrontal cortex, and bilaterally in the inferior frontal and temporal lobes (piriform cortex). In the present study we investigated brain function during different stages of olfactory memory processing.

Subjects were scanned during four tasks: odor encoding, long‐term odor recognition, short‐term odor recognition and a no‐odor sensorimotor control task. Subjects were 12 right‐handed healthy volunteers (6 men, 6 women). Each subject underwent a training session four days prior to their PET scan to learn the six odors required for the long‐term memory scan. PET scans were obtained with a Siemens Exact ECAT HR+ 3D system using H215O methodology and 60‐sec scanning intervals. PET images were coregis tered with each subject's magnetic resonance imaging scan, averaged, and transformed into standard stereotaxic space. Paired image subtractions were analyzed for rCBF changes.

Preliminary analyses have revealed significant activation of the right orbitofrontal region and bilateral piriform cortices during the long‐term odor recognition task compared with the control task. Activation of the right piriform cortex was present during the short‐term recognition task. Brain activity during encoding and retrieval tasks also involved prefrontal corti ces. PET activation studies of memory in other modalities have led to hypotheses of a hemispheric encoding/retrieval asymmetry in frontal cortex; the generalizability of this theory to olfactory memory will be discu ssed.
Functional Lateralization of Human Gustatory Cortex Related to Handedness Disclosed by fMRI Studya
Authors: CERF B. , LEBIHAN D. , VAN DE MOORTELE P. F. , MAC LEOD P. , FAURION A.
Published: February 2006

ABSTRACT: Ten healthy subjects aged 20‐25 including five right‐handed and five left‐handed according to the Dellatolas test participated in this functional magnetic resonance imaging (fMRI) study. A 3 Tesla whole‐body MR scanner allowed echo planar imaging (EPI)‐64 × 64 pixels, repetition time (TR) = 6 s,field of view (FOV) = 20 × 20 cm2‐associated to acute anatomical localization of activated foci (256 × 256 pixels). Subjects were bilaterally stimulated with NaCl 85 mM, aspartame 2 mM, quinine hydrochloride 1 mM, glycyrrhizic acid 0.5 μM, guanosine monophosphate 1 mM and d‐threonine 250 mM alternating with water. Stimuli and rinse were continuously pushed as bolus of 50 μl every 3 s to the subject's mouth through microsyringes. We detected brain activated areas by correlation of the MR signal to an on‐line perception profile recorded for each experiment and each subject with the finger‐span method. We found most activations in the insula and the perisylvian region in agreement with previous electrophysiological studies on monkeys and clinical reports in humans. The superior part of the insula was bilaterally activated, in accordance with a whole‐mouth stimulation. A striking lateralization related to handedness was found in a lower part of the insula. This projection in the dominant hemisphere, located in the same coronal plane as the upper insular activation, is the first evidence of a functional lateralization of brain processing involved in taste perception.
Chemosensory Alteration of Information Processinga
Authors: LORIG TYLER S. , ELMES DAVID G. , YOERG VIRGINIA L.
Published: February 2006

ABSTRACT: Previous research has found both facilitation and interference when odors are administered during the performance of cognitive tasks. The present research was designed to investigate the possibility that odors might differentially effect different varieties of cognitive tasks. Twelve subjects performed matched verbal, numeric, and spatial tasks as event‐related potentials were measured. Odors and tones were introduced as subjects completed the tasks in a paradigm optimized to produce disruption of performance. Results indicated that P300 amplitude to the task stimuli depended upon the type of task and the modality of the distractor. P300 amplitude was relatively consistent across tasks for the tone distractor. During the olfactory distractor, P300 amplitude was greater for the symbolic stimuli (verbal and numeric) and lower for the spatial. Reaction times to the various tasks did not differ as a function of the modality of the distractor.
Olfactory Evoked Responses and Identification Tests in Neurological Disease
Authors: Hawkes C. H. , Shephard B. C.
Published: February 2006

ABSTRACT: To assess the value of smell testing we used olfactory evoked potentials (OEP) and an identification test in multiple sclerosis, Parkinson's disease, motor neuron disease and Alzheimer's disease. Methods: The OEP to H2S (20 ppm) was obtained using an olfactometer designed to stimulate olfactory nerve endings only. Odor recognition was assessed by the University of Pennsylvania Smell Identification Test (UPSIT). In all instances the disease was 'definite' based on standard diagnostic criteria. Controls were derived from 156 healthy people. Results: 1) Multiple Sclerosis: 11/72 patients (15%) were abnormal on UPSIT. For OEP there was significant increase of latency and decrease in amplitude in 6/26 patients (23%). 2) Parkinson's Disease: 126/155 (81%) patients had an abnormal UPSIT score. 12/37 (32%) had prolonged latency with normal amplitude measurement on OEP, but 27 had absent or unclear readings. 4/10 with normal UPSIT displayed abnormality on OEP. 3) Motor Neuron Disease: 9/58 (16%) were abnormal on UPSIT. There was significant delay in 1/10 (10%) patients on OEP. 4) Alzheimer's Disease: UPSIT scores were abnormal in all 8 patients examined. OEP was normal in 4 of these who could be tested. Conclusion: Smell dysfunction was found in all 4 conditions but most severely in Parkinson's Disease (over 80%). The UPSIT in general showed abnormality more frequently than OEP. The olfactory defect probably involves peripheral structures in all diseases tested except Alzheimer's. A patient with normal olfaction is unlikely to have idiopathic Parkinson's disease.
Developmental Effects on Odor Learning and Memory in Childrena
Authors: JEHL CHRISTINE , MURPHY CLAIRE
Published: February 2006

ABSTRACT: The child version of the California Odor Learning Test (COLT) was designed to assess cognitive functioning in impaired and healthy children. The COLT's rationale was based on two assumptions. First, measures of cognitive functioning are a good index of severity or extent of brain damage if compared between normal and clinical populations. Second, the cognitive‐mediated tasks of verbal odor recall, recognition and identification were suitable to evaluate cognitive functioning. The focus of this study was to determine the COLT's ability to detect developmental differences in odor learning and memory. The participants were 51 healthy children who were twice administered the COLT with a weekly delay between tests. They were ascribed to two age‐groups (7‐10 and 11‐15 years old) according to levels of cognitive development. The COLT employed 22 common odors and included two sessions. In the first session, children learned two sets of six odors. The first set was presented three times, the second one once, during a single learning episode. Following learning, children recalled the odors of the first set by name at free recall and category‐cued recall. The second session included the following tasks: long‐term free odor recall and category‐cued odor recall, odor recognition‐memory and verbal odor identification. A series of analyses of variance (ANOVAs, p <0.05) with age as between‐subject variable and repeated measurements on recall revealed significant differences between the two groups on the number of odors correctly recalled by name both at free recall, category‐cued recall, recognition and identification. There were differences in false alarms at odor recognition between the two groups. Children from both groups benefited from a learning effect over odor trials. A gender effect was found for odor free recall at retest. These results suggest that the COLT has the potential to serve as a useful tool in the assessment of cognitive functioning in children.
Metrics of Odorant Dissimilarity: Labeled Magnitude Scale vs Magnitude Estimationa
Authors: Kurtz DANIEL B. , WHITE THERESA L.
Published: February 2006

ABSTRACT: Magnitude estimation (ME) has long been the standard rating tool for stimulus intensity because of the simplicity and generalizability of the resultant power function relationships. However, the choice of a scaling procedure for rating complex stimuli (odorant) dissimilarity must be based on a different set of criteria due to an inability to evaluate relationships against a physical continuum. Recently, chemosensory labeled magnitude scales (LMS) have been developed, which produce ratings with many of the same properties as ME. The current study sought compare LMS to ME as metrics for describing the magnitude of perceived odorant dissimilarity. Forty subjects rated pair‐wise odorant dissimilarity with either a LMS or ME. Each subject evaluated two sets of odorants with differing ranges of dissimilarity (high contrast and low contrast) in order to compare the sensitivity of the two measures to possible contrast convergence. The ME ratings were normalized such that the two metrics produced equal means. The scales produced similar ratings of odorant dissimilarity (r= 0.92) and showed small but similar effects of contrast convergence. However, the coefficient of variation of dissimilarities rated with ME was 2.8 times that of dissimilarities rated with the LMS. Subjects accepted the LMS without the usual anxiety that accompanies first time users of ME. LMS provide stable ratings of odorant dissimilarity while preserving the inferred ratio scale properties of ME.
Draize Eye Scores and Eye Irritation Thresholds in Man Can Be Combined into One QSARa
Authors: ABRAHAM MICHAEL H. , KUMARSINGH RACHEL , COMETTO‐MUÑIZ J.ENRIQUE , CAIN WILLIAM S.
Published: February 2006

ABSTRACT: Draize eye scores (DES) of 37 pure organic liquids have been converted into scores for the corresponding vapors, DES/P0, where P0 is the liquid vapor pressure in atmospheres at 298 K. It is shown that there is a constant difference of 6.7 between values of log(DES/P0) and log (1/EIT), where EIT is the eye irritation threshold in parts per million (ppm, by volume) of eight vapors for human subjects. The 37 log(DES/P0) values can be combined with log(1/EIT) values for 17 vapors into one quantitative structure‐activity relationship (QSAR) for sensory potency (SP) using our general solvation equation,Equation 1

image

where R2 is an excess molar refraction, π2H the compound polarizability/dipolarity, Σα2H and Σβ2H are the compound hydrogen‐bond acidity and basicity, and L16 is the gas‐hexadecane partition coefficient at 298 K. n is the number of data points, r the correlation coefficient, SD the standard deviation, and F the F‐statistic. LogSP is then either [log(DES/P0) ‐ 0.66] or log (1/EIT), confirming the result for the eight common compounds. It is suggested that the equation can be used to predict eye irritancy of organic vapors and pure liquids. It is further suggested that for the compounds in the data set, the main process in eye irritation is transfer of the compound from the vapor or pure liquid to a biological phase, and a number of chemical properties of the biological phase have been mapped out through the equation. These properties are consistent with corresponding properties for a number of organic liquid phases.
Using Olfaction to Study Memory
Authors: EICHENBAUMA HOWARD
Published: February 2006

ABSTRACT: In a series of studies we have been exploring the role of hippocampal function in memory using the model system of olfactory‐hippocampal pathways and odor learning in rats. Our experiments show that hippocampus itself is not essential to memory for single odors, but is critical for forming the representations of relations among odor memories, and for the expression of odor memory representations in novel situations. These studies that exploit the exceptional qualities of olfactory learning are helping to clarify the nature of higher order memory processes in all mammals, and extending to declarative memory in humans.
Semantic Mediation of Age‐Related Deficits in Episodic Recognition of Common Odorsa
Authors: LARSSON MARIA , BÄCKMAN LARS
Published: February 2006

ABSTRACT: In the present research, the relationship between various semantic memory functions and episodic odor memory across the adult life span is addressed. In contrast to earlier evidence that odors may be encoded and stored as unique, nonlinguistic whole percepts, the present work suggests that episodic odor information is mediated by factors that can be subsumed under the rubric of semantic memory. Specific olfactory knowledge, such as perceived familiarity and identifiability, is strongly and positively related to episodic odor memory performance. In contrast to research using verbal and visual stimuli, proficiency in complex verbal intellectual abilities, such as vocabulary and fluency, seems to be of minor importance in memory for olfactory information. In agreement with earlier findings, this research indicates that episodic odor memory deteriorates across the adult life span. A similar negative age trend was observed for odor naming. Most importantly, statistical control of odor naming resulted in the elimination of age‐related odor memory deficits. These results suggest that age‐related failures in accessing specific semantic information of odors determine largely age‐related deficits in episodic odor recognition.
Abnormality of Semantic Network in Patients with Alzheimer's Disease: Evidence from Verbal, Perceptual, and Olfactory Domainsa
Authors: CHAN AGNES , SALMON DAVID , NORDIN STEVEN , MURPHY CLAIRE , RAZANI JILL
Published: February 2006

ABSTRACT: A series of studies was initiated to model the organization of semantic memory in Alzheimer's disease (AD) patients using multidimensional scaling (MDS) and Pathfinder analyses. The resulting models (cognitive maps or semantic networks) embed studied stimuli in a coordinate space or network where distances between points are assumed to reflect psychological proximity between items. The organization of semantic networks in verbal and sensory domains were modeled based upon the frequency of the subject's choice of two concepts as most alike. Results suggested that while the organization of concepts in the semantic networks of AD patients was primarily based upon a concrete perceptual dimension in both verbal and olfactory domains, those of normal controls subjects were predominantly organized by an abstract conceptual attribute. Also, networks of AD patients were more complex and chaotic than normal, that is, they consisted of more unnecessary connections and of atypical strengths of association between concepts.
Human Olfactory Bulb: Aging of Glomeruli and Mitral Cells and a Search for the Accessory Olfactory Bulba
Authors: MEISAMI ESMAIL , MIKHAIL LAURA , BAIM DARRIN , BHATNAGAR KUNWAR P.
Published: February 2006

ABSTRACT: The aims of this study on the human olfactory bulb were two. First morphometry of the bulbs revealed marked declines during aging in the numbers of mitral cells and glomeruli, the bulb's principal integrative and relay elements. Numbers of glomeruli and mitral cells in each bulb of the young adult human were found to be approximately 8,000 and 40,000, respectively; these numbers declined steadily with age at an approximate rate of 10% per decade, so that in the ninth and tenth decades less than 30% of these elements remain in place. Such a marked decline with aging is suggested to underlie in part the decline in olfactory abilities (odor detection and identification) of humans with aging. In a separate study a systematic search for presence of an accessory olfactory bulb in the adult and aging bulbs was undertaken. No positive evidence for such an organized formation was found in the various regions of the adult bulbs of different age groups. The implications of these negative findings for the recent theories on human vomeronasal function and pheromonal perception are discussed.
Apolipoprotein E Status is Associated with Odor Identification Deficits in Nondemented Older Personsa
Authors: MURPHY CLAIRE , BACON ANNA W. , BONDI MARK W. , SALMON DAVID P.
Published: February 2006

ABSTRACT: Alzheimer's disease (AD) patients with moderate dementia show losses in olfactory threshold, odor identification and odor memory. Sensitivity and specificity of olfactory testing is significant, with the greatest power of accurate diagnosis in the more cognitively loaded olfactory tasks. In patients with very mild AD or in patients at risk for the disease because of their mild cognitive impairment, losses are apparent for odor identification, odor recognition memory and odor threshold, with the best sensitivity in the identification task. Persons who are either heterozygous or homozygous for the ɛ4 allele of apolipoprotein E (ApoE) have an increased risk of Alzheimer's disease, although they show no dementia in the preclinical period. Evidence of olfactory dysfunction in this population might be reflective of an incipient dementing process. We have recently examined olfactory function in a group of normal elderly persons who have undergone genetic testing for the Apoe4 allele. These individuals consisted of all normal control subjects at the University of California, San Diego (UCSD) Alzheimer's Disease Research Center (ADRC) who had undergone both the genetic testing and testing for olfactory function. All had been diagnosed as normal control participants by two different neurologists who applied the National Institute of Neurological Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINDS‐ADRDA) criteria for dementia. Persons with a history of alcoholism, drug abuse, learning disability or neurologic or psychiatric illness (including depression) were excluded. In this population, persons with the Apoe4 allele showed significantly poorer odor identification than those without an ɛ4 allele. Early appearance of olfactory deficits in the progression to AD in persons with the ɛ4 allele suggests diagnostic utility in olfactory testing.
Viral Replication in Olfactory Receptor Neurons and Entry into the Olfactory Bulb and Braina
Authors: REISS CAROL SHOSHKES , PLAKHOV ILIA V. , KOMATSU TAKASHI
Published: February 2006

ABSTRACT: This communication describes our ongoing studies of the interaction of the mouse host and vesicular stomatitis virus (VSV). When VSV is applied to the nasal neuroepithelium, it initially replicates in olfactory receptor neurons, and is transmitted along the olfactory nerve to the central nervous system (CNS) within 12 hours. In the olfactory bulb, the virus replicates invasively through the layers of the olfactory bulb, reaching the olfactory ventricle by day 4‐5 post infection, and the hindbrain by day 8 post infection. In mice, infection may result in a 50% mortality rate. The crucial host innate and specific immune responses responsible for restricting vital propagation and caudal spread of the virus will be discussed. The efficacy of interleukin‐12 (IL‐12) treatment for enhanced vital clearance and promotion of host recovery are described along with the implications for treatment of human encephalitis. The hosts' response to infection is also regulated by the sex of the host, and the age at infection. The role of specific mucosal humoral immunity and systemic cellular immunity in prevention of infection are described.
Cellular and Molecular Neuropathology of the Olfactory Epithelium and Central Olfactory Pathways in Alzheimer's Disease and Schizophreniaa
Authors: ARNOLD STEVEN E. , SMUTZER GREGORY S. , TROJANOWSKI JOHN Q. , MOBERG PAUL J.
Published: February 2006

ABSTRACT: Specific deficits in odor detection threshold, identification, and memory have been recognized in a variety of disorders including the neurodegenerative disorder, Alzheimer's disease (AD), and the psychiatric illness, schizophrenia, which is likely due to abnormalities in neurodevelopment. Neuropathological abnormalities in peripheral and central olfactory systems have been described in both disorders. In the olfactory epithelium, dystrophic neurites that are immunoreactive for tau, neurofilaments and other polypeptides, as well as deposits of β‐amyloid have been observed, and these findings have been thought to contribute to the olfactory dysfunction of these disorders. However, similar findings also occur in the olfactory epithelium of many normal individuals and those with various other neurodegenerative diseases. In contrast, neuropathological studies have reported selective vulnerability of central olfactory pathways for the accumulation of neurofibrillary pathology in AD, and for cytoarchitectural, neuronal morphometric, and cytoskeletal protein abnormalities suggestive of abnormal neurodevelopment in schizophrenia. Thus, it is likely that the olfactory impairments associated with these diseases are due to damage within central olfactory pathways, and that they are further amplified by the less specific impairments associated with age‐related sensory neuroepithelial abnormalities. Finally, both the olfactory epithelium and central olfactory pathways represent model systems in which to study the neurobiology of these disorders, which ultimately may yield clues with diagnostic and therapeutic utility.
PROP Taster Status Is Related to Fat Perception and Preferencea
Authors: TEPPER BEVERLY J. , NURSE RICKY J.
Published: February 2006

ABSTRACT: Individuals who are sensitive to the bitter compound 6‐n‐propylthiouracil (PROP) are also more sensitive to selected bitter and sweet substances, to sharp foods and to the trigeminal irritant capsaicin. PROP tasters have a greater density of fungiform papillae, and it is speculated that they also have more trigeminal innervation. Since oral texture perception is also mediated, in part, by trigeminal fibers, it has been proposed that individual differences in fat perception might also be linked to PROP taster status and taste bud density. This work tests the hypothesis that individuals who are PROP tasters: (i) have a higher density of fungiform papillae; (ii) are more sensitive to capsaicin; and (iii) have increased ability to discriminate differences in fat content in salad dressing. Hedonic ratings for the salad dressing were also collected and related to the perceptual judgments. Individual subjects were classified as PROP nontasters, medium tasters or supertasters (n= 25/group) by comparing their psychophysical function for PROP to that of NaCl. Papillae densities (papillae/cm2) were significantly different among the three taster groups (p <0.0001), and were highest among the supertasters. Both medium tasters and supertasters perceived more oral burn from capsaicin than did nontasters at concentrations of 50, 70 and 100 ppm (p <0.0001). Medium tasters and supertasters could also discriminate differences in fat content between 40% fat and 10% fat salad dressings (p <0.005), but the nontasters could not. Although medium and supertasters showed no preference for either dressing, the nontasters preferred the 40% fat sample. The reasons for these latter findings are unclear at present. These data support the hypothesis that fat perception and preference can be linked to genetic and anatomical differences between individuals.
Taste Changes across Pregnancya
Authors: DUFFY VALERIE B. , BARTOSHUK LINDA M. , STRIEGEL‐MOORE RUTH , RODIN JUDITH
Published: February 2006

ABSTRACT: We examined taste intensity and preference in 46 pregnant and 41 healthy female controls enrolled in the Yale Pregnancy Study (J. Rodin, PI). Pregnant females were tested non‐pregnant (non‐pg) and during the first, second and third trimesters; controls, at corresponding time intervals. Subjects rated intensity of and preference for a three‐member concentration series of NaCl, sucrose, citric acid (CA), and quinine hydrochloride (QHCl) on a labeled line ('nothing' at the left, 'extremely' at 80%). Variance differences between groups were tested with the F distribution (p <0.05). Controls hadsignificantly greater variance among overall intensity ratings than pregnant females, most pronounced for QHCl. Controls did not have highest variance among overall hedonic ratings, but did have highest variance for sweet and QHCl ratings. Within pregnancy analyses were tested with the Friedman two‐way ANOVA. Significant intensity changes occurred for moderate NaCl and QHCL concentrations (p <0.005). For NaCl, intensity fell from non‐pg and first trimester to second and third trimesters. For QHCl, intensity rose from non‐pg to first trimester, and fell from first to second and third trimesters. In the hedonic ratings, significant changes occurred for top concentrations of NaCl (p <0.05) and 0.001 M CA (p <0.001), and moderate QHCl (p <0.005). NaCl preference rose from non‐pg to third trimester. Preference for CA fell from non‐pg to first trimester and then rose from first to second and third trimesters. QHCl became less disliked from non‐pg and first trimester to third trimester. Summary: taste intensity and hedonic variance in controls may associate with menstrual hormone fluctuations. Pregnant women were aligned in pregnancy stage which may explain the lower variance. Taste intensity and hedonic changes across pregnancy could serve to support healthy pregnancy outcomes: increases in bitter intensity in first trimester to protect against ingesting poisons; changes in NaCl, sour and bitter preference later in pregnancy to support ingesting a varied diet.
Threshold Distributions of Phenylthiocarbamide (PTC) in the Chinese Populationa
Authors: GUO SUN‐WEI , SHEN FU‐MIN , WANG YUE‐DONG , ZHENG CHANG‐JIANG
Published: February 2006

ABSTRACT: The ability to taste phenylthiocarbamide (PTC) is a well‐documented Mendelian trait. Mapping and cloning the gene(s) responsible for the PTC tasting ability would help to delineate the molecular basis for the variations in PTC tasting ability in humans and to shed new light on taste chemosensory functions. In view of the spectacular successes in genome science, the positional cloning strategy seems to be a feasible approach to the isolation of the gene(s) underlying the PTC tasting ability. As a first step toward mapping the gene(s), we collected PTC taste threshold data on 106 individuals, most of them being university students, in Shanghai, China. Using various parametric and nonparametric statistical methods, we have found that the data set is best described by a bimodal distribution. The frequency of PTC nontasters is estimated to be 10%. This is consistent with the view that the PTC nontasting ability follows a recessive mode of inheritance. Several authors had previously reported PTC data on Chinese living outside China. Our data are, to our knowledge, the first ever collected from the Chinese population within China.
The Perceived Bitterness of Beer and 6‐n‐Propylthiouracil (PROP) Taste Sensitivity
Authors: INTRANUOVO LINDA R. , POWERS ALICE S.
Published: February 2006

ABSTRACT: Pelchat and Danowski found a significantly higher proportion of nontasters of 6‐n‐propylthiouracil (PROP) among children of alcoholics than among children of nonalcoholics, suggesting a possible genetic association between alcoholism and PROP tasting ability. They suggested that nontasters may not find alcohol as bitter as tasters do and may be at greater risk for alcoholism because they like the taste of alcoholic beverages more. In the present study we tested this hypothesis by examining how nontasters, medium tasters, and supertasters of PROP judged the taste of two kinds of beer.

Forty‐seven males and 53 females between the ages of 21 and 49 rated the perceived bitterness of Budweiser and Pilsner Urquell on the oral Labeled Magnitude Scale (LMS). Subjects also rated their degree of liking or disliking for the two beers on a 9‐point. Likert scale. PROP papers and the LMS were used to classify subjects into tasting groups.

The results lent some support to the hypothesis in that male nontasters liked the taste of Pilsner Urquell better than male supertasters, when they tasted Pilsner Urquell after Budweiser. (This finding was not replicated for females.) Also, as subjects' ratings of bitterness for the two beers increased, their degree of liking for the taste decreased. Supertasters rated Pilsner Urquell significantly more bitter than medium tasters. Subjects were asked about their drinking habits, and supertasters reported consuming significantly less beer than nontasters when they first started drinking beer on a regular basis. There were no significant differences in current drinking behavior between tasting groups. These results suggest that supertasters are distinct from nontasters with regard to their taste for beer and may to some degree be protected against alcoholism by their dislike for bitter substances.
Psychophysical Measurement of 6‐n‐Propylthiouracil (PROP) Taste Perceptiona
Authors: LUCCHINA LAURIE A. , CURTIS V OTIS F. , PUTNAM PETER , DREWNOWSKI ADAM , PRUTKIN JORDAN M. , BARTOSHUK LINDA M.
Published: February 2006

ABSTRACT: The ability to taste 6‐n‐propylthiouracil (PROP) is genetically determined. PROP tastes moderately bitter to 'medium tasters' (MT), intensely bitter to 'supertasters' (ST), and tasteless to 'nontasters' (NT). The psychophysical method used to characterize PROP status should capture the entire range of perception, while minimizing context, ceiling and other effects. Magnitude estimation successfully captures the variability in PROP perception, but requires normalization and may be difficult to conduct in industrial settings. Two labeled scales were tested as part of three separate studies (S1, S2 and S3) to measure perceived intensity of PROP and sweeteners. All studies included reportedly healthy volunteers aged 21‐62 years recruited at Cultor Food Science in Groton, CT. In S1 [n= 163 (55 males, 108 females)], subjects rated perceived intensity of PROP‐saturated paper and sucrose (1.0 M) on the Labeled Magnitude (Green) Scale (LMS) [labeled line with descriptors (no taste‐strongest imaginable)]. In S2 [n= 152 (49 males, 103 females)], subjects rated perceived intensity of sucrose (1.0 M) and PROP solutions (0.001 M,0.0032 M) on the LMS. In S3 [n= 136 (48 males, 88 females)], subjects rated perceived intensity of sucrose (1.0 M) and PROP solutions (0.001 M, 0.0032 M) on a 9‐point category scale (1 = not al all; 9 = extremely). In all experiments, water rinses were included between each tastant and PROP was the final stimulus. Statistical analyses included descriptive statistics, regression analysis, and ANOVA. In S1 and S2, those with higher PROP perception perceived sucrose more intensely [(S1: r = 0.32; p <0.001); (S2: r = 0.25; p <0.01)]. A higher frequency of females were ST than males. Also, the PROP effect on sweet perception was most evident in female ST. This apparent sex difference may be the result of hormonal variation associated with menstruation. As well, in S1 and S2 subjects aged 20‐40 years, females had significantly greater variance among sucrose intensity ratings than males (F= 3.66; p < 0.01), which may be due to hormonal changes with menses. The S3 results failed to show either the positive correlation between PROP and sucrose perception or the sex difference. Thus of the two labeled scales, the LMS appears to be better for assessing PROP perception, as it is continuous and also minimizes ceiling effects. Future research will extend these studies by including sucrose and high intensity sweetener concentration series.
Oral Irritant Effects of Nicotine: Psychophysical Evidence for Decreased Sensation following Repeated Application of and Lack of Cross‐Desensitization to Capsaicina
Authors: DESSIRIER JEAN‐MARC , O'MAHONY MICHAEL , CARSTENS E.
Published: February 2006

ABSTRACT: When delivered to the oral mucosa, a variety of naturally occurring chemicals such as capsaicin from red chili peppers, piperine from black pepper, and nicotine from tobacco, cause a diffuse burning sensation often referred to as irritation. The burning sensation evoked by capsaicin increases when delivered repeatedly at 1 min intervals (sensitization), but then decreases markedly following a 10 min rest period (self‐desensitization. It is also interesting that following desensitization by capsaicin, irritant sensations evoked by other chemicals are also reduced (cross‐desensitization), suggesting that oral irritation from some agents may be mediated by a population of capsaicin‐sensitive trigeminal polymodal nociceptors.

Although nicotine is a major component in tobacco smoke, little is known about its sensory properties. Accordingly, a study of the oral irritant effects of nicotine as compared with capsaicin was initiated.

Whereas capsaicin (0.5 or 3 ppm; repeated at 1 min intervals over 10 min) evoked significantly stronger sensations (sensitization), there was a significant decrement in sensations to repeated application of nicotine (0.1%). After the subjects had received either repeated capsaicin or nicotine on one side of the tongue, a rest period ensued followed by a bilateral application of either capsaicin or nicotine. Subjects were, then, asked to choose which side yielded a stronger sensation (two‐alternative forced choice). Following capsaicin pretreatment, all subjects reported that capsaicin evoked a stronger sensation on the previously unseated side (capsaicin self‐desensitization). Similar self‐desensitization was observed with nicotine. Furthermore, nicotine was reported to evoke a significantly weaker sensation on the side of the tongue pretreated with capsaicin (cross‐desensitization). In contrast, equal numbers of subjects reported capsaicin to evoke a stronger sensation on either the nicotine‐pretreated side or the untreated side, indicating an absence of cross‐desensitization. These results are discussed in terms of physiological mechanisms that might underlie the contrasting sensory effects of nicotine versus capsaicin.
Detection of Very Complex Taste Mixturesa
Authors: STEVENS JOSEPH C.
Published: February 2006

ABSTRACT: Mixtures can often be tasted when all components are too weak to be tasted separately. Such mixtures are said to be integrative. Integration was demonstrated by mixing compounds in concentrations proportional to their separate detection thresholds and then measuring the detection threshold of the mixture as a whole by forced choice with plain water. Mixtures of 3, 6, 12 and 24 compounds were thus evaluated. With earlier data on 2‐, 3‐ and 4‐component mixtures, the results show that the concentration of any constituent compound goes down in approximate proportion to the number of compounds with which it is in mixture. This nearly complete integration describes mixtures of like‐quality compounds, of unlike‐quality compounds, and of both like‐ and unlike‐quality compounds together. Integrative mixtures provide a model for the detection of the ultracomplex stimuli of everyday life, such as foods and drinking waters. Although the degree of integration may trail off slightly with mixtures of high complexity, the results proffer no limit on the number of compounds that can be at least partially integrated. In principle, integration permits detection of natural substances whose myriad components could all be far below threshold. The mechanism of taste integration is speculative, but the facts are congenial to the hypothesis of multiple parallel channels for the processing of intensity and quality.
Temporal Processing of Odor Mixtures Reveals That Identification of Components Takes Precedence over Temporal Information in Olfactory Memorya
Authors: JINKS ANTHONY , LAING DAVID G. , HUTCHINSON IAN , ORAM NICHOLAS
Published: February 2006

ABSTRACT: Temporal processing of binary mixtures results in odorants being perceived in series separated by many hundreds of milliseconds. Since the odorant perceived first is the main suppressor, knowledge of the order of perception of two odorants can allow prediction of interactions in mixtures. The present study investigated the temporal coding of ternary mixtures composed of carvone, coniferan and triethylamine, and citralva, lillial and triethylamine using a specially constructed air‐dilution olfactometer. The results indicated that even though each of the components could be readily identified in ternary mixtures, it was very difficult to indicate which odor was perceived first, with chance scores being recorded. The same outcome occurred even when the 'slowest' odorant was delivered 600 ms after the 'fastest' to the nose. It is proposed that olfactory memory gives precedence to identification of the components of mixtures rather than to their order of perception when more than two odorants are in a mixture.
An Integrated Model of Intensity and Quality of Odor Mixtures
Authors: OLSSON MATS J.
Published: February 2006

ABSTRACT: Several models of how odors mix to form new percepts have been presented during the last decades. Almost all these models have concerned the perceived intensity of mixtures rather than the perceived quality of mixtures. In 1994 Olsson suggested an integrated model for how perceived intensity and quality of the mixture can be predicted from the perceived intensities of the single substances. A generalized version of this model is proposed here. The model can be viewed as an extension of vector summation. The current study reviews support for this model. In doing that, assumptions of the model are defined and tested against data. It is shown how odor interaction, when the process is seen from the view of the observer, reduces to a set of simple rules that are consistent across levels of intensity and combinations of odorants.
The Design Principles of Axilla Deodorant Fragrances
Authors: McGEE THOMAS , RANKIN KRYSTYNA M. , BAYDAR AHMET
Published: February 2006

ABSTRACT: There are a number of ways that deodorant products control malodor: a) by suppressing sweat, b) by inhibiting bacterial activity, and c) by covering malodor. The paper focuses on the Givaudan Roure methodology used to develop fragrances that effectively cover malodor. Several steps are involved in the development of a successful deodorant fragrance. First, we test for substantivity of the deodorant fragrance material in the axilla, using odor value technology. Second, using an in vitro test with reconstituted axilla odor, we determine the effectiveness of the substantive fragrance material with carefully screened panelists. Third, using a multichannel olfactive blender, the perfumer creates a fragrance heart with effective deodorant fragrance materials that cover malodor in the vapor phase. Finally, the hedonically pleasing heart is used to create the final fragrance, which is then optimized using our in vitro test method.
Factors Affecting the Perception of Naturalness and Flavor Strength in Citrus Drinks
Authors: KING BONNIE M. , DUINEVELD C.A. A.
Published: February 2006

ABSTRACT: In two profiling experiments and one grouping experiment, panelists evaluated orange drinks in order to measure the effects of design variables, especially color, on basic tastes as well as on more consumer‐like attributes such as flavor strength and naturalness. Naturalness was increased in one experiment by lowering degrees Brix or increasing quinine HCl. Low sweet‐sour ratios were generally perceived as more natural. Pectin had no effect on naturalness. Flavor strength was increased consistently by augmenting levels of quinine HCl, sucrose, citric acid or degrees Brix. Addition of Cochineal Red increased sweetness and flavor strength but decreased the perception of naturalness for the aromas studied.
Role of the Taste System in Ingestive Behavior: Studies in NaCl and Fatty Acid Transductiona
Authors: GILBERTSON TIMOTHY A.
Published: February 2006

ABSTRACT: The transduction of tastants involves a variety of mechanisms both within and across stimulus classes. Taste stimuli have been shown to permeate and block ion channels, activate both ionotropic and metabotropic receptors and directly permeate the membrane of taste receptor cells. Though significant progress has been made in recent years in elucidating the mechanisms of taste transduction, there has been comparatively little emphasis placed upon investigating how the transduction process in taste receptor cells is modulated. Moreover, because of the general opinion that the sense of taste has little or no direct role in the regulation of ingestive behavior, there have been few studies aimed at directly assessing the link between the performance of the peripheral gustatory system and underlying nutritional preferences. Recent work in our laboratory in NaCl and fatty acid transduction supports the idea that the transduction of taste stimuli is a very dynamic process that both contributes to the control of ingestive behavior and is reflective of underlying nutrient preferences.
Transcriptional Control of the Galanin Gene: Tissue‐Specific Expression and Induction by NGF, Protein Kinase C, and Estrogen a
Authors: RÖKAEUS ÅKE , JIANG KAI , SPYROU GIANNIS , WASCHEK JAMES A.
Published: February 2006

Abstract: Galanin is a neuropeptide widely expressed in the central and peripheral nervous system where it acts as a neurotransmitter/neuromodulator and possibly an immunoregulator and growth factor. Galanin gene expression is highly regulated during development and by certain hormones and injury situations. We have examined transcriptional control mechanisms for this gene using chimeric bovine galanin/luciferase reporter genes. These were analyzed in cultured cells and in transgenic mice. The studies reveal that enhancer and silencer sequences are involved in conferring cell‐ and tissue‐specific expression, and that specific elements close to the promoter are responsible for nerve growth factor and protein kinase C induction. So far, the studies have not revealed sequences on the bovine gene that mediate the action of estrogen.
Analysis of Selected Regulatory Pathways for Rat Galanin Gene Transcription and Their Suitability As Putative Models for Negative Regulation by NGF a
Authors: CORNESS JACQUELINE , HÖKFELT TOMAS
Published: February 2006

Abstract: Nerve growth factor (NGF) is known to negatively regulate the transcription of the rat galanin gene both in vivo and in vitro in dorsal root ganglion neurons, yet it is unclear how this regulation actually occurs. We propose here several possible pathways whereby NGF could interact to exert negative control on galanin regulation. These include: (1) repression of AP1‐mediated transcription, (2) repression of nuclear binding protein‐mediated transcription, and (3) repression of cytokine‐mediated transcription. Although not enough data are available for speculation on which, if any, of these pathways is most relevant for NGF repression of galanin transcription, the mechanisms we describe can provide putative models for regulatory pathways. From here we can carry out further experiments that may help to elucidate the possible mechanisms of NGF repression in vivo.
Targeted Disruption of the Murine Galanin Gene a
Authors: WYNICK DAVID , SMALL CAROLINE J. , BLOOM STEPHEN R. , PACHNIS VASSILIS
Published: February 2006

Abstract: The 29 amino acid neuropeptide galanin is widely distributed in the nervous and endocrine systems; highest levels of galanin synthesis and storage occur within the hypothalamus in the median eminence, but it is also abundantly expressed in the basal forebrain, the peripheral nervous system, and gut. To further define the role played by galanin in the peripheral nervous and endocrine systems, a mouse strain carrying a loss‐of‐function germ‐line mutation of the galanin locus, engineered by targeted mutagenesis in embryonic stem cells, has been generated. The mutation removes the first five exons containing the entire coding region for the galanin peptide. Germ‐line transmission of the disrupted galanin locus has been obtained, and the mutation has been bred to homozygosity on the inbred 12901aHsd background. Phenotypic analysis of mice lacking a functional galanin gene demonstrate that these animals are viable, grow normally, and can reproduce. A marked reduction in both the anterior pituitary prolactin content and in circulating plasma levels of the hormone is evident. Lactation is abolished along with abrogation of the proliferative response of the lactotroph to estrogen. The responses of sensory neurons to injury in the mutants are markedly impaired. Peripheral nerve regeneration is reduced with associated long‐term functional deficits. There is a striking reduction in the development of chronic neuropathic pain. These two phenotypic changes may be explained, in part, by the observation that a subset of dorsal root ganglion neurons is lost in the mutant animals, implying a role for galanin as a trophic cell survival factor. These initial findings have important implications for our understanding and potential therapeutic treatment of (a) sensory nerve regeneration and neuropathic pain and (b) disordered pituitary proliferation and the development of prolactinoma.