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G K Beauchamp

Publications and source records attributed to G K Beauchamp.

At least 55 records · Page 3Linked to original sources
PubMed1996

Ethanol consumption and taste preferences in C57BL/6ByJ and 129/J mice.

Mice of the C57BL/6ByJ (B6) and 129/J (129) strains were offered different concentrations of taste solutions in 48-hr, two-bottle choice tests. In comparison with the 129 strain, the B6 strain had higher preferences for ethanol, sucrose, and citric acid. They had lower preferences for NaCl and similar preferences for capsaicin and quinine hydrochloride. These data are consistent with the hypothesis that the higher ethanol intake by B6 mice depends, in part, on higher hedonic attractiveness of its sweet taste component.

Alcohol Drinking↗
PubMed1996

Monogeusia for fructose, glucose, sucrose, and maltose.

We investigated the ability of subjects to discriminate sugars with a whole-mouth forced-choice paradigm, in which a standard solution was compared with a test solution of varied concentration. Discrimination probabilities were U-shaped functions of test concentration: for 6 subjects and pairwise combinations of fructose, glucose, and sucrose, discriminability always declined to chance over a narrow range of test concentrations. At concentrations < or = 100 mM, maltose was indiscriminable from fructose but discriminable at higher concentrations for 4 subjects. By analogy with the monochromacy of night vision, whereby any two lights are indiscriminable when their relative intensities are suitably adjusted, we call the gustatory indiscriminability of these sugars monogeusia. The simplest account of monogeusia is that all information about the indiscriminable sugars is represented by a single neural signal that varies only in magnitude. The discriminability of maltose from the other sugars at higher concentrations is consistent with the hypothesis that maltose also activates a second gustatory code.

Adult↗
PubMed1995

Evidence suggesting that the odortypes of pregnant women are a compound of maternal and fetal odortypes.

Odortypes--namely, body odors that distinguish one individual from another on the basis of genetic polymorphism at the major histocompatibility complex and other loci--are a fundamental element in the social life and reproductive behavior of the mouse, including familial imprinting, mate choice, and control of early pregnancy. Odortypes are strongly represented in urine. During mouse pregnancy, an outcrossed mother's urine acquires fetal major histocompatibility complex odortypes of paternal origin, an observation that we took as the focus of a search for odortypes in humans, using a fully automated computer-programmed olfactometer in which trained rats are known to distinguish precisely the odortypes of another species. Five women provided urine samples before and after birth, which in each case appropriately trained rats were found to distinguish in the olfactometer. Whether this olfactory distinction of mothers' urine before and after birth reflects in part the odortype and hence genotype of the fetus, and not just the state of pregnancy per se, was tested in a second study in which each mother's postpartum urine was mixed either with urine from her own infant or with urine of a different, same-aged infant. Responses of trained rats were more positive with respect to the former (congruous) mixtures than to the latter (incongruous) mixtures, implying that, as in the mouse, human fetal odortypes of paternal genomic origin are represented in the odortype of the mother, doubtless by circulatory transfer of the pertinent odorants.

Animals↗
PubMed1995

Garlic ingestion by pregnant women alters the odor of amniotic fluid.

Amniotic fluid samples were obtained from 10 pregnant women undergoing routine amniocentesis procedure. Approximately 45 min prior to the procedure, five of the women ingested placebo capsules, whereas the remaining five ingested capsules containing the essential oil of garlic. Randomly selected pairs of samples, one from a woman who ingested garlic and the other from a woman who ingested placebo capsules, were then evaluated by a sensory panel of adults. The odor of the amniotic fluid obtained from four of the five women who had ingested the garlic capsules was judged to be stronger or more like garlic than the paired samples collected from the women consuming placebo capsules. Thus, garlic ingestion by pregnant women significantly alters the odor of their amniotic fluid.

Adult↗
PubMed1995

Suppression of bitterness by sodium: variation among bitter taste stimuli.

Taste interactions between salts (NaCl, LiCl, KCl, L-arginine:L-aspartic acid, Na-acetate and Na-gluconate) and bitter-tasting compounds (urea, quinine HCl, magnesium sulphate, KCl, amiloride HCl and caffeine) were investigated. In each study binary combinations of three or four concentrations of one bitter compound with four concentrations (0, 0.1, 0.3 and 0.5 M) of one salt were rated for bitterness and saltiness using the method of magnitude estimation. In most cases, perceived bitterness was suppressed by salts, although the degree of suppression varied. In general, bitterness suppression was not accompanied by an equivalent reciprocal suppression of saltiness. Only MgSO4 and amiloride had suppressing effects on the saltiness of NaCl at the intermediate concentrations and no bitter compound affected the saltiness at the high concentrations of NaCl. Since salt suppressed the bitterness of urea effectively, a detailed analysis of suppression of the bitterness of urea by different salts was conducted. Those studies indicated that the key component in this effect was the sodium or lithium ion for two reasons: first, all three sodium salts and the lithium salt had a suppressive effect on bitterness, whereas KCl did not; secondly, the effect of a salt on suppression of the bitterness of urea was independent of its perceived saltiness; that is, NaCl, Na-acetate (which is perceived as less salty than NaCl), and Na-gluconate (which is perceived as less salty than Na-acetate) reduced bitterness comparably. These results suggest that there is a major peripheral component to the suppression of the bitterness of urea, and perhaps other bitter tasting compounds, by sodium.

Adult↗
PubMed1994

Discrimination of odortypes determined by the major histocompatibility complex among outbred mice.

Genetically determined body odors that distinguish one mouse from another are termed odortypes. The best known odortypes, highly expressed in urine, are those specified by H-2, the major histocompatibility complex of the mouse, but other odortypes originate from unidentified loci in the rest of the genome, including both sex chromosomes. The definition of H-2 odortypes and evidence that their perception affects reproductive behavior have so far depended on studies with inbred mouse strains whose genetic differences are confined to the H-2 complex of genes. To simulate feral conditions more closely, a freely segregating population was bred from crosses involving four unrelated inbred strains contributing four different H-2 haplotypes. After H-2 typing, this outbred population was divided into four groups of freely segregating mice, comprising the four distinct H-2 genotypes represented, to serve as conventional donors of urine for evaluation in the standard Y-maze system used in the training and testing of mice for H-2 odortype discrimination. With respect to utility in training mice for H-2 odortype discrimination, and to degrees of concordance attained in the Y-maze by trained mice, these urinary H-2 odortype sources from outbred mice were no less effective than urines customarily obtained for those purposes from nonsegregating inbred donors. We conclude that discrimination of H-2 odortypes is not appreciably affected or impaired by the usual concurrent segregation within the genome as a whole.

Animals↗
PubMed1994

Infant salt taste: developmental, methodological, and contextual factors.

Two studies investigated the human infant's response to salt during development. In the first study, measures of intake and sucking were obtained from two groups of infants, newborns and 4- to 8-month-olds, in response to brief presentations of two concentrations of salt (0.2 or 0.4 M) and water. For several measures of sucking and for intake, there were significant age and concentration effects. Generally, newborn infants tended to reject saline relative to water more than did 4- to 8-month-old infants. This result, consistent with previously published research, suggests a developmental change in salt acceptability and, probably, sensitivity in the human infant. In the second longitudinal study, the response to salted (0.15 M) versus unsalted formulas was evaluated monthly in infants 2 to 7 months of age. Again, a developmental change was observed: Based on some sucking measures, younger infants appeared to be indifferent to the salted formula relative to the unsalted formula whereas older infants tended to reject the salted formula, presumably because either it was less sweet than the unsalted formulas or because it was novel. These data are consistent with the hypothesis developed from animal model studies that during early human postnatal development, transductive elements sensitive to saltiness mature.

Dose-Response Relationship, Drug↗
PubMed1994

Fetal H-2 odortypes are evident in the urine of pregnant female mice.

The major histocompatibility complex (MHC) imparts to each mouse an individual urinary odor, called "odortype", which reflects its MHC genotype. Perception of odortypes affects mate selection and embryonic implantation. Recent findings that odortypes are expressed as early as one day of age suggested that they might already be expressed in utero. We now report that at 9-12 days of gestation, odortypes specified by paternal (non-maternal) MHC haplotypes become apparent in maternal urine. Thus, odortypes are expressed in utero, can be sensed even before birth, and may serve in familial identification and communication.

Animals↗
PubMed1994

Bitter taste in aging: compound-specific decline in sensitivity.

Threshold sensitivity to and the perceived intensity of two bitter compounds, quinine sulfate and urea, were assessed in 52 young adults and 60 elderly adults. Consistent with previous literature, age-related declines in sensitivity to the bitterness of quinine were observed at both threshold and suprathreshold levels. In contrast, the same young and elderly subjects showed comparable sensitivity to the bitterness of urea. These results provide further support for the existence of multiple bitter taste transduction sequences in humans, and indicate that they may be differentially affected by aging.

Adolescent↗
PubMed1994

Chemical senses.

In the last decade, studies using approaches from molecular biology have substantially advanced our understanding of the early events in olfaction and taste. The many odorants that we can recognize may well interact with many distinct receptor proteins. Of the four taste qualities that we recognize, studies on salty and sour suggest that these tastes involve ion channels in the membrane of receptor cells while sweets and bitters bind to receptor proteins. Some volatiles (pheromones) play special roles in reproductive behavior via the vomeronasal organ (VNO) and the accessory olfactory system. Initial belief that humans lack a VNO has been questioned recently, thus raising the fascinating possibility of human pheromones. The roles that taste and smell play in the world of the newborn are very different. Acceptance of sweet and rejection of bitter appear to be hard-wired while the affect associated with odors depends much more on experience. Genetic variation may produce total losses (Kallman's syndrome produces anosmia and familial dysautonomia produces ageusia) or losses specific to certain stimuli. The best known of the specific anosmias is that for androstenone, which has no smell to some, a urinous smell to others, and a smell like sandalwood to still others. Analogous to the specific anosmias, some individuals are unable to taste PROP while others, supertasters, perceive PROP to be exceedingly bitter. Clinical studies reveal pathologies responsible for total or partial losses. The olfactory system, dependent on one cranial nerve, is more vulnerable than taste, and total anosmia is a relatively common clinical problem. Three cranial nerves carry taste and two of those nerves inhibit one another such that damage to one disinhibits the other and preserves over-all taste function. Total ageusia is very rare. Throughout these studies we see that taste and olfaction have different properties and often different functions (e.g. odor and reproduction). Yet taste and smell can also be integrated to determine what does or does not enter the body. In Adrian's words, "we are dealing with the sense organs which signal the quality of the air we breathe and that of the food and drink we propose to swallow."

Ageusia↗
PubMed1993

Beer, breast feeding, and folklore.

Beer consumption by nursing women altered the sensory qualities of their milk and the behavior of their infants during breast-feeding in the short term. The infants consumed significantly less milk during the 4-hr testing sessions in which their mothers drank alcoholic beer compared to when the mothers drank nonalcoholic beer; this decrease in milk intake was not due to a decrease in the number of times the babies fed. Although the infants consumed less of the alcohol-flavored milk, the mothers believed their infants had ingested enough milk, reported that they experienced a letdown during nursing, and felt they had milk remaining in their breasts at the end of the majority of feedings. Moreover, the mothers terminated the feeds the same percentage of time on both testing days. The mechanism by which the consumption of alcoholic beer by lactating women decreases milk intake by their nurslings remains to be determined.

Adult↗
PubMed1993

Olfactory discrimination of urinary odortypes from congenic strains (DBA/1Bg and DBA1.C57BL10-YBg) of mice differing in their Y chromosomes.

Differential effects of one or more genes in the nonpseudoautosomal region of the DBA1 and C57BL10 Y chromosomes on offensive attack may be mediated, at least in part, by differential effects of this Y chromosomal gene(s) on the sending and receiving of discriminable urinary odortypes. This hypothesis is based, in part, on the report that urine from a pair of Y chromosomal congenic strains (C57BL6.AKR-Y and C57BL6) of mice can be discriminated in a Y maze test. The AKR and C57BL6 Y chromosomes come from two distinct species of mouse (Mus domesticus and Mus musculus, respectively). Thus, this Y chromosomal variant exists between mouse species. The DBA1 and C57BL10 Y chromosomes come from a single species, Mus musculus. Here we show that in the Y maze system previously used, urine from mice with the DBA1 and with the C57BL10 Y chromosomes can also be discriminated. Thus, there are discriminable urinary odortypes for this pair of Y chromosomes from the same species, Mus musculus.

Animals↗
PubMed1993

Strain differences in consumption of saline solutions by mice.

Intake of saline (NaCl) solutions and water by males of two inbred strains of mice [C57BL/6J (C57) and 129/J] were examined using 48-h, two-bottle preference tests. There was a large strain difference in saline intake: at moderate concentrations (0.075-0.150 M) C57 mice tended to reject saline relative to water, whereas 129/J mice preferred it. Both strains of mice increased their intake of saline following lasix-induced sodium depletion and the preference exhibited by 129/J mice for 0.15 M NaCl was eliminated following LiCl toxicosis. The rejection of moderate concentrations of saline by C57 was shown to be due, in part at least, to prior exposure to iso- or hypertonic saline solutions: C57 mice that had no prior exposure to saline exhibited a greater intake of saline than C57 mice previously exposed to 0.30 M NaCl. Saline preferences of the 129/J mice were not affected by prior exposure to 0.30 M NaCl. Thus, the strain difference in mouse salt preference is due in part to postingestional consequences of saline consumption in C57 but not 129/J mice.

Animals↗
PubMed1993

The effects of repeated exposure to garlic-flavored milk on the nursling's behavior.

The present study investigated whether prior consumption of garlic by nursing mothers modifies their infant's behaviors during breast-feeding when the mothers again consume garlic. Three groups of mother-infant dyads were studied. The groups differed in the type (placebo or garlic) or the timing (d 5-7 or 8-10) of capsule ingestion by the mothers and, consequently, in the amount and recency of exposure their infants had to garlic-flavored milk during an 11-d experimental period. Each mother-infant pair was observed during two 4-h test sessions. The first session occurred at the beginning of the experimental period, when the mothers ingested placebo capsules (d 4); the second occurred at the end of the experimental period, when they ingested garlic capsules (d 11). During test sessions, the infants fed on demand and were weighed before and after each breast-feeding to determine the amount of milk ingested, and their behaviors during breast-feeding were monitored by videotape. The results demonstrated an effect of prior experience with garlic in mother's milk. The infants who had no exposure to garlic volatiles in their mothers' milk during the experimental period spent significantly more time breast-feeding after their mothers ingested garlic capsules compared with those infants whose mothers repeatedly consumed garlic during the experimental period. Moreover, the former group of infants spent significantly more time attached to their mothers' breasts during the 4-h test session in which their mothers ingested the garlic compared with the session in which she ingested the placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Feeding↗
PubMed1992

Expression of urinary H-2 odortypes by infant mice.

The extended H-2 complex of genes in the mouse includes at least three loci that independently specify distinctive body odors, "odortypes," whose differential recognition influences mating choice and affects the maintenance of early pregnancy. A prime experimental method of identifying H-2 odortypes is the specially designed Y-maze in which mice are trained, by water deprivation and reward, to distinguish odors conducted to the arms of the maze from H-2-dissimilar mice or their urines. It is confirmed that H-2-dissimilar infant mice, unlike adult mice, are not distinguished by trained mice in the Y-maze. However, a previous conclusion that infant mice do not express H-2 odortypes is shown to be incorrect, because the urines of H-2-dissimilar infant mice, even at 1 day of age, were distinguished in the Y-maze. Thus urine, ingested by the mother, clearly could suffice for her to distinguish her own from other H-2-dissimilar pups. Further, urine would seem to be a unique source of H-2 odortypes. If, as we believe, H-2 odortypes represent mostly compound odors composed by H-2 genetic variation in the urinary output of odorous metabolites, as distinct from simple odors that depend on chemical differences of single odorants, then the kidney, which is not responsible for H-2 odortype specificity, may nevertheless impart a unique character to urinary odortypes by virtue of differential excretion/resorption processing of various constituent odorous metabolites. In that case, various organs and tissues, among which the hematopoietic/lymphoid system is known to contribute to H-2 odortype specificity, may exhibit tissue-specific varieties of H-2 odortypes, their products having not yet been subjected to renal processing.

Age Factors↗
PubMed1992

Early developmental change in bitter taste responses in human infants.

Human newborns (birth-6 days) and older infants (14-180 days) were allowed to ingest both urea (0.12-0.24 M) in a mildly sweet diluent and the diluent alone, and multiple measures of responsivity were obtained (relative intake, sucking behavior, and hedonic ratings based on facial expressions and body movements). For newborns, there was no indication of rejection of urea relative to the diluent in measures of intake or sucking behavior; rather, their responses were predominantly controlled by the order of presentation of the two tastes. In contrast, older infants tended to reject all concentrations of urea according to these measures. Hedonic ratings provided an indication of limited rejection of the bitter taste by newborns, but older infants were still found to respond more consistently. These data suggest there is an early developmental change in bitter taste perception.

Facial Expression↗