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PubMed1989

Stress-reducing effects of ingesting milk, sugars, and fats. A developmental perspective.

A developmental approach to the study of feeding is proposed that considers social complexity and its biological mediation as core determinants of later ingestive patterns. Evidence is presented for opioid-mediated influences of milk and its major constituents and for nonopioid-mediated channels for contact comfort. Consideration of these factors might help us better understand some of the determinants of human feeding disorders such as bulimia and anorexia nervosa.

Animals↗
PubMed1981

[Experimental studies for the hygienic standardization of Lasso in water].

Experimental hygienic-toxical study was carried out on amide herbicide lasso, aiming at its hygienic standardization in water. The studies were carried out in three aspects for the determination of its effect upon the organoleptic qualities of water, on the sanitary regime of water-reservoirs and toxic effect on organism. Threshold and subthershold concentrations of the deleterious effect on colour, small and taste of water were determined as well as on B0N5, on sanitary-indication microflora and on cold blooded organisms. The toxicological parameters for acute, subacute and chronic oral toxicity on albino rats were established. On the base of the experimental studies, differentiated hygienic norms (MAC) of lasso were elaborated in the three categories water-reservoirs - I mg/1 for I category and 5 mg/1 for II and II category.

Animals↗
PubMed1992

Decreased NaCl sensitivity in zinc-deprived rats.

NaCl thresholds and ability to discriminate between NaCl and sucrose were assessed in rats using an operant discrimination conditioning procedure before and during moderate and severe zinc deprivation and during zinc supplementation. NaCl thresholds were approximately 1 mM before dietary zinc manipulation. They increased in all zinc-deprived rats tested 10 and 17 days after initiation of deprivation but did not change in pair-fed controls maintained on supplemental zinc. Threshold changes were greater for those rats severely zinc deprived than for those only moderately deprived and were greater as the period of deprivation lengthened. Plasma zinc concentrations decreased significantly in deprived rats from values obtained at baseline, values in severely deprived rats being significantly lower than in those only moderately deprived. Although zinc-deprived rats discriminated NaCl from sucrose, they made more discrimination errors than controls. Following 24 days of zinc supplementation, previously deprived rats exhibited no significant improvement in gustatory performance, although their body weight increased and plasma zinc concentrations increased; but these later changes were not significant. These results demonstrate that zinc deprivation induces decreased gustatory sensitivity and confirm a role for zinc in taste.

Animals↗
PubMed2002

Gustatory function of the soft palate.

Several characteristics of the gustatory function of the soft palate principally elucidated by our own recent investigations, as well of those of others, are described. The soft palate has a gustatory function which is independent of the tongue and is innervated by the greater petrosal nerve. Taste papillae of the soft palate are morphologically similar to the fungiforme papillae which exist on the anterior part of the tongue. In individuals aged approximately 20 years, gustatory functions of the soft palate, examined by means of the electro-gustatory and filter paper disk test's are as good as those of the tongue innervated by the chorda tympani and glossopharyngeal nerve. In younger individuals, the gustatory function of the soft palate plays as important a role as that of the tongue. Gustatory thresholds of the soft palate, as well as those of other sites innervated by other taste nerves, tend to be elevated with aging, and the degree of elevation in the soft palate is much greater than that of other sites. The most sensitively perceived taste at the soft palate is a sweet taste in the majority of subjects. Taste papillae of the palate in rats become flattened and decrease in number with age. These changes are more prominent in zinc-deficient rats.

Age Factors↗
PubMed1976

Hyperinsulinemia: effects on body weight, obesity and motivated behaviors.

Five experiments were performed to evaluate the physiological and behavioral similarities between lesions of the ventromedial hypothalamus (VMH) and injection-produced hyperinsulinemia. It was found that the rate of weight gain and fat deposition in both adult and weanling rats was essentially the same for both VMH and hyperinsulinemic rats. Measures of activity and taste preference measures yielded no differences between hyperinsulinemic rats and intact rats. Electric shock thresholds revealed a decrease in reactivity for hyperinsulinemic rats compared to intact rats. A hypothesis was suggested in which a combination of hypophysectomy, gonadectomy, and hyperinsulinemia might produce most of the physiological effects seen with VMH lesions. It was also suggested that since these physiological alterations radically modify the organism's internal environment, the behavioral effects of VMH lesions may be the results of the attempts of a brain-damaged animal to maintain new physiological conditions.

Adipose Tissue↗
PubMed2000

Smell and taste in children with simple obesity.

In 30 children, aged 10-16 years and suffering from simple obesity, significantly lowered odour detection thresholds were noted. The thresholds were lower than the average for a given age group in around 20% of obese children in cases of odours stimulating olfactory nerve and in around 57% in cases of substances stimulating olfactory and trigeminal nerves. Odour identification thresholds were similarly affected, with identification of olfactory nerve plus trigeminal nerve stimulating odours affected more than twice as frequently. In 77% cases also the electrogustometric thresholds were found below the normal range values when anode was used as the stimulating electrode. The detected alterations may be linked to metabolic disturbances, which accompany simple obesity.

Adolescent↗
PubMed1990

Chemospecific deficits in taste detection after selective gustatory deafferentation in rats.

Electrophysiological data support the existence of sodium-specific taste receptors that appear to be limited to the anterior tongue. However, previous behavioral findings suggest that bilateral transection of the chorda tympani nerve (CTn) has minimal consequences on NaCl intake and preference. This study employed a conditioned avoidance procedure to measure detection thresholds to NaCl and sucrose both before and after bilateral transection of the CTn. Rats were trained to maintain spout contact in response to water presentations (70 microliters) and to avoid spout contact when a taste solution (70 microliters) was presented. In experiment 1, all rats (n = 3) showed statistically significant impairments in the detectability of NaCl after bilateral section of the CTn. The mean increase in the NaCl detection threshold was 1.41 log units. In contrast, sucrose threshold in these same rats was marginally affected by CTn section (mean increase = 0.22 log units). Experiment 2 (n = 4) replicated the findings of the first experiment. The mean increase in the NaCl detection threshold was 2.23 log units. Sucrose threshold in these rats was, again, only marginally affected by CTn section (mean increase = 0.83 log units). Histological examination of the anterior tongue from the rats in experiment 2 indicated that the CTn transections were complete. These findings reveal that the anterior oral receptive field (innervated by the CTn) containing only 15% of the total taste bud population is critical for the normal detection of NaCl.

Afferent Pathways↗
PubMed1977

[Analysis of the effect of bicarbonate on taste receptor sensitivity to organic acids].

Addition of NaHCO3 or NaOH to the solutions of lactic or pyruvic acids decreased threshold concentrations of H+ ions and increased intensity of afferent impulsation in the cat chroda tympani nerve. In spite of the fact that the concentrations of both lactate and pyruvate anions with the presence of NaOH and NaHCO3 are the same at equal pH values the observed changes of the receptors responses were more intensive if NaHCO3 had been added. Therefore the influence of NaHCO3 on the perception of organic acids depends not only on its buffer properties but, probably, on direct action of CO2 appearing as the result of interaction of NaHCO3 and acids, as well. This assumption was confirmed by the data on high sensitivity of the cat tongue receptors for the carbon dioxide.

Animals↗
PubMed2004

Relating ionisation of calcium chloride in saliva to bitterness perception.

Saliva plays a role in the perception of bitter, sour and salty tastes that are presumed to be derived from the concentration of free cations or anions ions dissolved in saliva. The role of ionisation of calcium in bitter taste was studied by determining binding in vitro mixture of saliva and protein solutions and in spit. In vitro, the addition of whey to calcium chloride solutions increased the calcium binding, pH and viscosity. The addition of saliva to these mixtures, the increased calcium binding and the induced small changes in viscosity and pH were thought not to contribute significantly to bitterness perception. Nonstimulated saliva, at pH 7.5, contained about 5 mM calcium, of which about one third was ionised. The bitter threshold of fully ionised calcium chloride in water varied between 1 and 15 mM among individuals. In spit, after tasting whey, ionised calcium was found to have increased at low, but decreased at high, calcium concentrations and varied 30% among individuals. Bitterness was related, on average, to the concentration of ionised calcium and not to the total concentration of calcium in spit. A general explicative model based on the composition of bulk saliva is discussed in relation to perception threshold and the likely importance of saliva from von Ebner's gland.

Adult↗
PubMed1995

Estimation of the junctional resistance between electrically coupled receptor cells in Necturus taste buds.

Junctional resistance between coupled receptor cells in Necturus taste buds was estimated by modeling the results from single patch pipette voltage clamp studies on lingual slices. The membrane capacitance and input resistance of coupled taste receptor cells were measured to monitor electrical coupling and the results compared with those calculated by a simple model of electrically coupled taste cells. Coupled receptor cells were modeled by two identical receptor cells connected via a junctional resistance. On average, the junctional resistance was approximately 200-300 M omega. This was consistent with the electrophysiological recordings. A junctional resistance of 200-300 M omega is close to the threshold for Lucifer yellow dye-coupling detection (approximately 500 M omega). Therefore, the true extent of coupling in taste buds might be somewhat greater than that predicted from Lucifer yellow dye coupling. Due to the high input resistance of single taste receptor cells (> 1 G omega), a junctional resistance of 200-300 M omega assures a substantial electrical communication between coupled taste cells, suggesting that the electrical activity of coupled cells might be synchronized.

Animals↗
PubMed2002

Fourth ventricular CART reduces food and water intake and produces a conditioned taste aversion in rats.

Cocaine- and amphetamine-regulated transcript peptide (CART) reduces rats' intake of liquid diet if the peptide reaches the 4th ventricle (4V). To test for specificity of 4V CART effects on feeding, the authors compared its ability to reduce intakes of liquid diet and water and tested for conditioned taste aversion (CTA). CART reduced 30-min intakes of both water and Ensure at a threshold of 1 microg. Lithium chloride (0.15 M, 20 ml/kg i.p.) and 4V CART (1 microg) paired with novel saccharin solution reduced saccharin preferences similarly in subsequent 2-bottle tests, compared with saline. Thus, CART can produce CTA. These data demonstrate that 4V CART's actions in ingestive behavior are not specific to nutrients and suggest that aspects of 4V CART's actions in reducing intake may be secondary to the production of an aversive state.

Analysis of Variance↗
PubMed2000

Assessment of smell and taste in patients with allergic rhinitis.

We examined the senses of smell and taste in 240 patients with verified hypersensitivity reactions of the respiratory tract. Olfactometry was performed according to Elsberg and Levy's method and followed by electrogustometry. The examinations revealed that the incidence of smell and taste disorders in patients with allergic rhinitis is 21.4% and 31.2%, respectively. No significant relationships between smell and taste dysfunction were found. We evaluated statistically positive correlations between the olfactory and gustatory thresholds compared with 78 qualitative and quantitative factors assessed in the study. There was a statistically significant relationship between the olfactory thresholds and levels of eosinophils in blood and in nasal discharge. acid reaction of the nasal mucosa, coexisting nasal polyps and X-ray changes in the ethmoid sinuses. There was a positive influence of pharmacotherapy as well as specific desensitization and surgery on the impairment of the sense of smell in allergic rhinitis.

Adolescent↗
PubMed1986

Opiate blockade inhibits saccharin intake and blocks normal preference acquisition.

Recent evidence indicates a close connection between oral sensory function and opioid effects on feeding. Not only is gustatory motivation influenced by opiate drugs but apparently gustatory stimuli can also activate central opiate receptor systems. In 3 experiments we studied the effect of opiate receptor blockade on drinking motivated by the sweet taste of saccharin. Experiment 1 established a dose-response function for inhibition of intake by naloxone (NAL) in short (60 min) 2-bottle tests. This experiment demonstrated the extreme sensitivity of nondeprived, nonstressed animals to NAL and estimated the MED50 at less than 0.1 mg/kg (SC), well below the threshold for effects due to illness or general motor disturbance. Experiment 2 further demonstrated that NAL's effectiveness depends on saccharin concentration. In particular, the lowest NAL dose studied was effective near the threshold for saccharin preference but not at higher concentrations. These data suggest that endogenous opioid systems may be activated by taste stimuli in a graded fashion. Finally, experiment 3 showed that the typical acquisition of preference for a moderate saccharin concentration can be effectively blocked by daily pre-test NAL injection. Together these experiments further demonstrate the close functional relationship between opioid systems and gustatory sensory systems.

Animals↗
PubMed1993

Behaviors of rats with insidious, multifocal brain damage induced by seizures following single peripheral injections of lithium and pilocarpine.

Several domains of behavior were measured in rats (n = 465) 10 days to 100 days after induction of limbic seizures by a single subcutaneous injection of lithium and pilocarpine. These rats displayed enhanced intragroup aggression but normal muricide; gustatory neophobia and conditioned taste aversion were virtually eliminated. Severe working and reference memory deficits were evident within the radial arm maze. Both state-dependent memory and possible situation-dependent precipitation of spontaneous seizures were suggested. The behavioral changes were considered commensurate with the multifocal pattern of thalamic, hippocampal/amygdaloid, and limbic cortical damage.

Acetylcholine↗
PubMed2005

Changes in gustatory function during the course of pregnancy and postpartum.

OBJECTIVE: To investigate changes in gustatory function during pregnancy and postpartum. DESIGN: Prospective study. SETTING: Obstetric outpatient clinic, Zurich University Hospital. POPULATION: Forty-four pregnant women, 46 controls. METHODS: A threshold-like measure of gustatory function was obtained for different concentrations of the four basic tastes using 'taste tablets'; subjects were also asked to rate the intensity and pleasantness/unpleasantness of suprathreshold taste solutions. Tests were performed in early pregnancy up to 14 weeks of gestational age, 8-12 weeks after the first and second examination and at least 6 weeks after birth. In parallel, controls were tested four times at intervals of 8-12 weeks. MAIN OUTCOME MEASURES: Gustatory score (number of correctly identified tastes). Results Pregnant subjects exhibited a decreased gustatory function compared with non-pregnant controls, still being present after birth. These 'objective' changes were observed although pregnant women rated the intensity of suprathreshold taste stimuli not significantly different from controls. Pregnant women rated salty stimuli to be more pleasant during the second trimester while they rated the salty stimuli to be less pleasant during the first and third trimester, and after birth. CONCLUSIONS: Pregnancy is accompanied by changes in gustatory function. Decreased gustatory sensitivity may allow pregnant and breastfeeding women to vary their diet in order to consume adequate electrolytes. The discrepancy between 'objective' and 'subjective' findings in gustatory function may relate to changes in central processing of gustatory information during pregnancy.

Adult↗