| 1. |
- Brodin, Malin, et al.
(författare)
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Odor Interaction between Bourgeonal and Its Antagonist Undecanal
- 2009
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Ingår i: CHEMICAL SENSES. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 34:7, s. 625-630
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Tidskriftsartikel (refereegranskat)abstract
- The perceived quality of a binary mixture will, as a rule of thumb, be dominated by the quality of the stronger unmixed component. On the other hand, there are mechanisms that, in theory, suggest that this will not always be true; one example being receptor antagonism. Undecanal has been indicated as an antagonist for bourgeonal-sensitive receptors in the human olfactory epithelium. Therefore, we investigated mixtures of isointense concentrations of bourgeonal and undecanal and, as a control, mixtures of isointense concentrations of bourgeonal and n-butanol. Both mixture types were investigated at 2 levels of concentration. The particular aim was to see if the bourgeonal-undecanal mixtures would exhibit asymmetric odor quality favoring the perception of the antagonist and the control mixture would not. For the control mixture, indeed odor quality tended to be dominated by the strongest component before mixing as would be suggested from previous studies. In line with the hypothesis, the bourgeonal-undecanal mixture was dominated by the antagonists quality, but only when mixed at higher concentrations, altogether suggesting the effects of a low-affinity receptor antagonism. This is, to our knowledge, the first demonstration of how antagonistic interaction at the level of the receptor can affect the perception of odor mixtures in humans.
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| 2. |
- Broman, Daniel, 1974-
(författare)
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Lateralization of human olfaction : cognitive functions and electrophysiology
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis lateralization of olfactory functions was investigated by both behavioral and electrophysiological assessment, the latter with the olfactory event-related potential (OERP) technique. The olfactory sense is primarily ipsilateral in that a stimulus that is presented to one nostril is initially processed in the same hemisphere. This makes it possible to observe differences between stimulated nostrils as an indication of hemispheric difference. Study I explored differences in olfactory cognitive functions with respect to side of rhinal stimulation and demonstrated that familiarity ratings are higher at right- compared to left-nostril stimulation. No differences were found in episodic recognition memory or free identification, possibly reflecting inter-hemispheric interactions in higher cognitive functions. Effects of repetition priming were present in odor identification and tended to be more pronounced when tested via left nostril. Study II further investigated the effect of previous exposure in odor identification by a different experimental set-up, and demonstrated effects of repetition priming when tested via left- but not right-nostril stimulation. This finding indicates the importance of reconsidering possible sequential effects in olfactory research. Study III examined methodological aspects of an OERP protocol with respect to stimulus duration, which was used in Study IV. No differences in amplitudes or latencies where found between the stimulus durations of 150, 200 and 250 ms, suggesting the commonly used duration of 200 ms in a standard protocol. Study IV investigated laterality effects in OERPs with respect to side of stimulation and electrode site. The results showed consistent amplitudes and latencies regardless of rhinal side of stimulation. Larger amplitudes were demonstrated on left hemisphere and midline compared to right hemisphere, possibly explained by smaller N1/P2 amplitudes at the right-hemisphere sites at left-nostril stimulation. Apart from a proposed OERP protocol, the findings support the notions of a right-hemisphere predominance in processes related to olfactory perception and indicate, in accordance with other findings, a left-side advantage in conceptual repetition priming.
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| 3. |
- Jildmalm, Ronald, et al.
(författare)
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Food Preferences and Nutrient Composition in Captive White-handed Gibbons, Hylobates lar
- 2008
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Ingår i: International journal of primatology. - : Springer Science and Business Media LLC. - 0164-0291 .- 1573-8604. ; 29:6, s. 1535-1547
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to assess spontaneous food preferences in captive white-handed gibbons and to analyze whether they correlate with nutrient composition. Via a 2-alternative choice test, we repeatedly presented 3 male Hylobates lar with all possible binary combinations of 10 types of food that are part of their diet in captivity and found the following rank order of preference: grape > banana = fig > apple > pear > honeydew melon > carrot > tomato > cucumber > avocado. Correlational analyses revealed a highly significant positive correlation between the food preference ranking and the total carbohydrate, fructose, and glucose contents of the foods (p < 0.01, respectively). With the exception of the trace mineral selenium (p < 0.05), there was no other significant correlation with any other macro- or micronutrient. In addition, the food preferences were stable across the day because rankings obtained from tests performed at 0900, 1200, and 1500 h, respectively, did not differ significantly (p > 0.05). Our results suggest that captive white-handed gibbons are not opportunistic, but selective feeders with regard to maximizing net gain of energy because only the content of carbohydrates, but not the contents of total energy, proteins, or lipids significantly correlate with the displayed food preferences. Further, the results suggest that captive Hylobates lar, in contrast to their free-ranging conspecifics, do not display marked changes in their food selection across the day.
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| 4. |
- Joshi, Dipa, et al.
(författare)
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Olfactory Sensitivity for Enantiomers and Their Racemic Mixtures-A Comparative Study in CD - 1 Mice and Spider Monkeys
- 2006
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Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 31:7, s. 655-664
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Tidskriftsartikel (refereegranskat)abstract
- Using a conditioning paradigm, the olfactory sensitivity of six CD-1 mice for the enantiomers of carvone and of limonene as well as for their racemic mixtures was investigated. With all six stimuli, the animals significantly discriminated concentrations 0.1 ppm (parts per million) from the odorless solvent, and with five of the six stimuli, the best-scoring animals were even able to detect concentrations 1 ppb (parts per billion). Five spider monkeys tested in parallel were found to detect the same stimuli at concentrations <1 ppm, and with two of the stimuli, they were also able to discriminate concentrations <1 ppb from the solvent. The results showed 1) both CD-1 mice and spider monkeys to have a well-developed olfactory sensitivity for the stimuli tested, with no systematic difference in performance between species; 2) the effect of chirality on detectability of the enantiomers to be substance specific; 3) no systematic effect of the presence (carvone) or absence (limonene) of a functional carbonyl group on detectability of the enantiomers; and 4) that spider monkeys detected the racemic mixtures of both carvone and limonene at lower concentrations compared to the unmixed compounds, whereas the mice failed to do so. These findings lend support to the growing body of evidence suggesting that between-species comparisons of the relative size of olfactory brain structures do not allow us to reliably predict olfactory sensitivity. As mice and spider monkeys are thought to share a similar number of functional olfactory receptor genes, the findings further suggest that differences in the relative abundance of chiral-specific olfactory receptor types might account for the observed difference in mixture additivity at threshold level between the two species. These threshold data may provide useful information for the choice of adequate stimulus concentrations in electrophysiological or imaging studies of the olfactory system or investigations of the discriminative abilities of mice and spider monkeys.
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| 5. |
- Laska, Matthias, et al.
(författare)
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Gustatory Responsiveness to Six Bitter Tastants in Three Species of Nonhuman Primates
- 2009
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 35, s. 560-571
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Tidskriftsartikel (refereegranskat)abstract
- Gustatory responsiveness of six adult squirrel monkeys, four spider monkeys, and five pigtail macaques to six bitter tastants was assessed in two-bottle preference tests of brief duration (2 min). Animals were given the choice between a 30-mM sucrose solution and defined concentrations of a bitter tastant dissolved in a 30-mM sucrose solution. With this procedure, Saimiri sciureus, Ateles geoffroyi, and Macaca nemestrina were found to significantly discriminate concentrations as low as 0.2, 0.05, and 0.1 mM quinine hydrochloride; 1, 1, and 0.05 mM caffeine; 20, 5, and 1 mM naringin; 5, 2, and 1 mM salicin; 0.01, 0.001, and 0.02 mM sucrose octaacetate; and 0.05, 0.01, and 0.5 mM denatonium benzoate, from the alternative stimulus. With the exception of naringin in the pigtail macaques, all three species rejected all suprathreshold concentrations of all bitter tastants tested. The spider monkeys and the pigtail macaques displayed the lowest taste avoidance thresholds with three of the six tastants each; in contrast, the squirrel monkeys displayed the highest taste avoidance thresholds with four of the six tastants. The across-tastant patterns of taste avoidance thresholds were identical in spider monkeys and squirrel monkeys; both species displayed the following order of sensitivity: sucrose octaacetate > denatonium benzoate > quinine hydrochloride > caffeine > salicin > naringin. All three primate species were more sensitive to the two artificial tastants (sucrose octaacetate and denatonium benzoate) compared to the four naturally occurring tastants. However, the concentrations detected by all three primate species with the four naturally occurring tastants are well below those reported in plants or arthropods consumed by these species suggesting that they may use bitterness as a criterion for food selection.
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| 6. |
- Laska, Matthias, et al.
(författare)
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How Big is the Gap between Detection and Recognition of Aliphatic Aldehydes?
- 2009
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Ingår i: Chemical Senses. - : Oxford University Press. - 0379-864X .- 1464-3553. ; 34:7, s. A108-A109
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- It is widely agreed that two different measures of olfactory sensitivity can be distinguished: a detection threshold, defined as the lowest concentration at which an odorant can be detected or discriminated from a blank stimulus, and a recognition threshold, defined as the lowest concentration at which an odorant can be assigned a recog- nizable quality or discriminated from another odorant. It is further widely agreed that the detection threshold is lower than the recog- nition threshold. Surprisingly few studies, however, have investi- gated the magnitude of the difference in concentration between olfactory detection and recognition thresholds. It was therefore the aim of the present study to determine olfactory detection thresh- olds for five aliphatic aldehydes (C4-C8) in a group of 16 human subjects, and to assess the ability of the same subjects to discrim- inate between the same odorants presented at different concentra- tions above their individual detection thresholds. We found that as a group the subjects significantly discriminated between 4 of the 10 odorant pairs when presented at a factor of 100, and 7 of the 10 odorant pairs when presented at a factor of 1000 above the individ- ual detection thresholds. The 3 remaining odorant pairs were not discriminated above chance level even when presented at a factor of 1000 above detection threshold. However, single subjects suc- cessfully discriminated between certain aldehyde pairs presented at a factor as low as 3 above detection threshold. Further, a signif- icant negative correlation between discrimination performance and structural similarity of the aldehydes tested was found. The results demonstrate that the gap between detection and recognition of aliphatic aldehydes is odorant pair-dependent but – at the grouplevel – spans at least a factor of 100.
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| 7. |
- Laska, Matthias, 1960-, et al.
(författare)
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Olfactory discrimination ability of CD-1 mice for a large array of enantiomers
- 2007
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522 .- 1873-7544. ; 144:1, s. 295-301
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Tidskriftsartikel (refereegranskat)abstract
- With use of a conditioning paradigm, the ability of eight CD-1 mice to distinguish between 15 enantiomeric odor pairs was investigated. The results demonstrate a) that CD-1 mice are capable of discriminating between all odor pairs tested, b) that the enantiomeric odor pairs clearly differed in their degree of discriminability and thus in their perceptual similarity, and c) that pre-training with the rewarded stimuli led to improved initial but not terminal or overall performance. A comparison between the proportion of discriminated enantiomeric odor pairs of the CD-1 mice and those of other species tested in earlier studies on the same discrimination tasks (or on subsets thereof) shows a significant positive correlation between discrimination performance and the number of functional olfactory receptor genes. These findings provide the first evidence of a highly developed ability of CD-1 mice to discriminate between an array of non-pheromonal chiral odorants. Further, they suggest that a species’ olfactory discrimination capabilities for these odorants may be correlated with its number of functional olfactory receptor genes. The data presented here may provide useful information for the interpretation of findings from electrophysiological or imaging studies in the mouse and the elucidation of odor structure-activity relationships.
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| 8. |
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| 9. |
- Laska, Matthias, 1960-, et al.
(författare)
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Olfactory discrimination of aliphatic odorants at 1 ppm : Too easy for CD-1 mice to show odor structure-activity relationships?
- 2008
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Ingår i: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology. - : Springer Science and Business Media LLC. - 0340-7594 .- 1432-1351. ; 194:11, s. 971-980
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Tidskriftsartikel (refereegranskat)abstract
- Using an operant conditioning paradigm we tested the ability of CD-1 mice to discriminate between 25 odorants comprising members of five homologous series of aliphatic odorants (C4-C8) presented at a gas phase concentration of 1 ppm. We found (a) that all mice significantly discriminated between all 50 stimulus pairs that involved odorants sharing the same functional group, but differing in carbon chain length, as well as between all 50 stimulus pairs that involved odorants sharing the same carbon chain length but differing in functional group, (b) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length with the acetic esters and the 2-ketones, but not with the 1-alcohols, n-aldehydes, and n-carboxylic acids tested, and (c) that odorant pairs differing in functional group were significantly better discriminated than odorant pairs differing in carbon chain length. These findings demonstrate that CD-1 mice have excellent discrimination ability for structurally related aliphatic odorants, that correlations between discrimination performance and structural similarity of odorants are odorant class-specific rather than a general phenomenon, and that both carbon chain length and type of functional group play an important role for odor quality coding in mice. © 2008 Springer-Verlag.
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| 10. |
- Laska, Matthias, et al.
(författare)
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Olfactory Discrimination of Aliphatic Odorants at 1 PPM - Too Easy for Mice to Show Odor Structure-Activity Relationships?
- 2008
-
Ingår i: Chemical Senses. - : Oxford University Press. - 0379-864X .- 1464-3553. ; 33:8, s. S158-S158
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Functional studies suggest that the neural representations of odorants vary systematically as a function of molecular structural features such as carbon chain length or functional group. Psychophysical studies in both humans and animal models have reported some correlations between perceived odor quality and these molecular properties but the generality of such correlations is unknown. Using an operant conditioning paradigm we therefore tested the ability of CD-1 mice to discriminate between 25 odorants comprising members of five homologous series of aliphatic odorants (C4-C8) presented at a gas phase concentration of 1 ppm. We found a) that all mice significantly discriminated between all 50 stimulus pairs that involved odorants sharing the same functional group, but differing in carbon chain length, as well as between all 50 stimulus pairs that involved odorants sharing the same carbon chain length but differing in functional group, b) a significant negative cor- relation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length with the acetic esters and the 2-ketones, but not with the 1-alcohols, n-aldehydes, and n-carbox- ylic acids tested, c) a lack of systematic differences in discrimination per- formance as a function of type of functional group, and d) that presentation of stimuli at 0.1 ppm did not impair discrimination perform- ance. These findings demonstrate that CD-1 mice have an excellent discrim- ination ability for structurally related aliphatic odorants. Given that olfactory discrimination performance critically depends on stimulus concen- tration, it may be that presentation of odorants at 1 ppm was too easy (that is: too high above detection threshold) for the mice to show consistent odorstructure-activity relationships.
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| 11. |
- Laska, Matthias, 1960-, et al.
(författare)
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Olfactory Sensitivity for Aliphatic Alcohols and Aldehydes in Spider Monkeys (Ateles geoffroyi)
- 2006
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Ingår i: American Journal of Physical Anthropology. - : Wiley. - 0002-9483 .- 1096-8644. ; 129, s. 112-120
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Tidskriftsartikel (refereegranskat)abstract
- A simple and general method for the preparation of ultrathin, large-area, free-standing films of nanofibrous composite materials was developed. First, positively charged cadmium hydroxide nanostrands of 1.9 nm in diameter and micrometers in length were prepared by mixing dilute aqueous solutions of cadmium chloride and aminoethanol. Negatively charged dye molecules, proteins, nanoparticles, and watersoluble fullerene or carbon nanotubes were mixed with the nanostrands to give a well-dispersed solution of the corresponding nanofibrous composites. After filtration of the dispersions with a polycarbonate membrane filter, uniform films with a thickness of a few tens to hundreds of nanometers and a diameter of a few centimeters were obtained. The films were readily peeled off from the membrane filter by immersion in ethanol. The resultant free-standing films could be further transferred to other substrates, such as quartz plate, gold electrode, and porous alumina membrane, and were characterized by scanning and transmission electron microscopies. We provide herein various nanofibrous free-standing films with optical, biological, metallic, and magnetic properties.
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| 12. |
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| 13. |
- Laska, Matthias, et al.
(författare)
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Olfactory sensitivity for alkylpyrazines - A comparative study in CD-1 mice and spider monkeys
- 2009
-
Ingår i: Journal of Experimental Zoology Part A: Ecological Genetics and Physiology. - : Wiley. - 1932-5223 .- 1932-5231. ; 311:4, s. 278-288
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Tidskriftsartikel (refereegranskat)abstract
- Using a conditioning paradigm, the olfactory sensitivity of four CD-1 mice for six alkylpyrazines was investigated. With all six stimuli, the animals discriminated concentrations =0.1 ppm (parts per million) from the odorless solvent, and with three of the six stimuli the animals were even able to detect concentrations =0.1 ppb (parts per billion). Four spider monkeys tested in parallel were found to detect five of the same six stimuli at concentrations less than1ppm and with one stimulus they were able to discriminate concentrations =1ppb from the solvent. The results showed CD-1 mice to be more sensitive than spider monkeys with five of the six alkylpyrazines tested. There was a significant positive correlation between sensitivity and the number of alkyl groups attached to the pyrazine (Pyr) ring in both species. A comparison of the detection thresholds obtained here to those obtained in human subjects suggests that neither the number of functional olfactory receptor genes nor the absolute or the relative size of the olfactory bulbs reliably predict a species olfactory sensitivity. These threshold data may provide useful information for the choice of adequate stimulus concentrations in electrophysiological or imaging studies of the olfactory system or investigations of the discriminative abilities of mice and spider monkeys.
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| 14. |
- Laska, Matthias, 1960-, et al.
(författare)
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Olfactory sensitivity for putrefaction-associated thiols and indols in three species of non-human primate
- 2007
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 210:23, s. 4169-4178
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Tidskriftsartikel (refereegranskat)abstract
- Using a conditioning paradigm, the olfactory sensitivity of four spider monkeys, three squirrel monkeys and three pigtail macaques to four thiols and two indols, substances characteristic of putrefaction processes and faecal odours, was assessed. With all odorants, the animals significantly discriminated concentrations below 1 p.p.m. (part per million) from the odourless solvent, and in several cases individual animals even demonstrated thresholds below 1 p.p.t. (part per trillion). The detection thresholds of 0.03 p.p.t. for indol in Saimiri sciureus and Macaca nemestrina and 0.96 p.p.t. for ethanethiol in Ateles geoffroyi represent the lowest values among the more than 50 odorants tested so far with these species and are in the same order of magnitude as the lowest detection thresholds reported so far in the rat and the mouse. The results showed (a) all three species of non-human primate to have a highly developed olfactory sensitivity for putrefaction-associated odorants, and (b) a significant correlation between perceptibility in terms of olfactory detection threshold and carbon chain length of the thiols, and a marked effect of the presence vs absence of a methyl group on perceptibility of the indols tested in two of the three species. The results support the hypotheses that (a) between-species differences in neuroanatomical or genetic features may not be indicative of olfactory sensitivity, and (b) within-species differences in olfactory sensitivity may reflect differences in the behavioural relevance of odorants.
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| 15. |
- Laska, Matthias, 1960-, et al.
(författare)
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Self-anointing behavior in free-ranging spider monkeys (Ateles geoffroyi) in Mexico
- 2007
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Ingår i: Primates. - : Springer Science and Business Media LLC. - 0032-8332 .- 1610-7365. ; 48:2, s. 160-163
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Tidskriftsartikel (refereegranskat)abstract
- During 250 h of observation, a total of 20 episodes of self-anointing, that is, the application of scent-bearing material onto the body, were recorded in a group of free-ranging Mexican spider monkeys (Ateles geoffroyi). The animals used the leaves of three species of plants (Brongniartia alamosana, Fabaceae; Cecropia obtusifolia, Cecropiaceae; and Apium graveolens, Umbelliferae) two of which have not been reported so far in this context in any New World primate species. The findings that only two males displayed self-anointing, that only the sternal and axillary regions of the body were rubbed with the mix of saliva and plant material, and a lack of correlation between the occurrence of self-anointing and time of day, season of the year, ambient temperature or humidity do not fit the hypothesis that this behavior functions in repelling insects and/or mitigating topical skin infections in this species. Rather, the data and the observation that the leaves of all three plant species spread an intensive and aromatic odor when crushed, support the hypothesis that self-anointing in A. geoffroyi may play a role in the context of social communication, possibly for signaling of social status or to increase sexual attractiveness.
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| 16. |
- Laska, Matthias, 1960-, et al.
(författare)
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Sex-Specific Differences in Olfactory Sensitivity for Putative Human Pheromones in Nonhuman Primates
- 2006
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Ingår i: Journal of comparative psychology (1983). - : American Psychological Association (APA). - 0735-7036 .- 1939-2087. ; 120:2, s. 106-112
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Tidskriftsartikel (refereegranskat)abstract
- In humans, the volatile C19-steroids androsta-4,16-dien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST) have been shown to modulate autonomic nervous system responses, and to cause hypothalamic activation in a gender-specific manner. Using two conditioning paradigms, the authors here show that pigtail macaques and squirrel monkeys of both sexes were able to detect AND and EST at concentrations in the micromolar and mM range, respectively. Male and female spider monkeys, in contrast, differed markedly in their sensitivity to these two odorous steroids, with males not showing any behavioral responses to the highest concentrations of AND tested and females not responding to the highest concentrations of EST. These data provide the first examples of sex-specific bimodal distributions of olfactory sensitivity in a nonhuman primate species.
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| 17. |
- Laska, Matthias, 1960-, et al.
(författare)
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Successful acquisition of an olfactory discrimination paradigm by South African fur seals, Arctocephalus pusillus
- 2008
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 93:4-5, s. 1033-1038
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Tidskriftsartikel (refereegranskat)abstract
- The present study demonstrates that South African fur seals, Arctocephalus pusillus, can successfully be trained to discriminate between objects on the basis of odor cues. Using a task based on a food-rewarded two-choice discrimination of simultaneously presented odor stimuli the animals acquired the basic operant conditioning paradigm within 480 to 880 stimulus contacts. Moreover, the fur seals could readily transfer to new S+ and S- stimuli, were capable of distinguishing between fish- and non-fish odors as well as between two fish odors, and were able to remember the reward value of previously learned odor stimuli even after 2- and 15-week breaks. The precision and consistency of the fur seals' performance in tests of discrimination ability and memory demonstrate the suitability of this paradigm for assessing olfactory function in this pinniped. An across-species comparison of several measures of olfactory learning capabilities such as speed of initial task acquisition and ability to master transfer tasks shows that A. pusillus is similar in performance to non-human primates, but inferior to rodents such as mice and rats. The results support the assumption that fur seals may use olfactory cues for social communication and food selection and that the sense of smell may play an hitherto underestimated role in the control of their behavior. © 2008 Elsevier Inc. All rights reserved.
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| 18. |
- Laska, Matthias, 1960-, et al.
(författare)
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Taste difference thresholds for monosodium glutamate and sodium chloride in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi)
- 2008
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Ingår i: American Journal of Primatology. - : Wiley. - 0275-2565 .- 1098-2345. ; 70:8, s. 839-847
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to determine taste difference thresholds for monosodium glutamate (MSG) and sodium chloride (NaCl) in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi). Using a two-bottle preference test of brief duration, three animals of each species were presented with four different reference concentrations of 50, 100, 200, and 400 mM of a tastant and tested for their ability to discriminate these from lower concentrations of the same tastant. The just noticeable differences (JNDs), expressed as Weber ratios (ΔI/I), were found to range from 0.1 to 0.5 for MSG and 0.2 to 0.45 for NaCl in the pigtail macaques, with a significant tendency for higher Weber ratios with higher reference concentrations. In the spider monkeys, JNDs ranged from 0.15 to 0.4 for MSG and 0.1 to 0.25 for NaCl, with Weber ratios staying fairly constant across the reference concentrations tested. Thus, the JNDs were found to be generally similar in both species and to be at least as low as those found in humans for MSG and NaCl, as well as those found in spider monkeys for sucrose. The results support the assumption that both pigtail macaques and spider monkeys may use differences in perceived intensity of MSG and NaCl as a criterion for food selection. © 2008 Wiley-Liss, Inc.
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| 19. |
- Laska, Matthias, 1960-, et al.
(författare)
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The Frequency of Occurrence of Acyclic Monoterpene Alcohols in the Chemical Environment does not Determine Olfactory Sensitivity in Nonhuman Primates
- 2006
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 32:6, s. 1317-1331
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Tidskriftsartikel (refereegranskat)abstract
- Using a conditioning paradigm, the olfactory sensitivity of five spider monkeys, three squirrel monkeys, and three pigtail macaques for six acyclic monoterpene alcohols that differ markedly in their frequency of occurrence in plant odors was assessed. The results showed that: (1) all three primate species have a well-developed olfactory sensitivity for acyclic monoterpene alcohols; (2) squirrel monkeys are significantly more sensitive for members of this class of odorants than the other two species and are able to detect all six odorants at concentrations below 0.1 ppm; and (3) there is a lack of positive correlations between olfactory sensitivity and the abundance of the acyclic monoterpene alcohols in flower odors and etheric oils. The results lend support to the growing body of evidence that suggests between-species comparisons of the number of functional olfactory receptor genes or of neuroanatomical features are poor predictors of olfactory performance. The findings do not support the hypothesis that olfactory sensitivity for members of a chemical class may be related to the frequency of occurrence of such odorants in a species' chemical environment.
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| 20. |
- Laska, Matthias, 1960-, et al.
(författare)
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Which senses play a role in nonhuman primate food selection ? A comparison between squirrel monkeys and spider monkeys
- 2007
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Ingår i: American Journal of Primatology. - : Wiley. - 0275-2565 .- 1098-2345. ; 69:3, s. 282-294
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Tidskriftsartikel (refereegranskat)abstract
- In order to optimize foraging efficiency and avoid toxicosis, animals must be able to detect, discriminate, and learn about the predictive signals of potential food. Primates are typically regarded as animals that rely mainly on their highly developed visual systems, and little is known about the role that the other senses may play in food selection. It was therefore the aim of the present study to assess which senses are involved in the evaluation of food by two species of New World primates: the squirrel monkey and the spider monkey. To this end, six animals per species were repeatedly presented with both familiar and novel food items, and their behavior was videotaped and analyzed. To obtain a further indication of the relative importance of visual and chemosensory cues, the animals were also presented with familiar food items that were experimentally modified in color, odor, or both color and odor. The results demonstrate that squirrel monkeys and spider monkeys use olfactory, gustatory, and tactile cues in addition to visual information to evaluate novel food, whereas they mainly inspect familiar food items visually prior to consumption. Our findings also show that in both species the use of nonvisual cues decreased rapidly with repeated presentations of novel food, suggesting a fast multimodal learning process. Further, the two species clearly differ in their relative use of nonvisual cues when evaluating novel or modified food, with spider monkeys relying more on olfactory cues than squirrel monkeys, and squirrel monkeys relying more on tactile cues compared to spider monkeys.
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