| 1. |
- Hernandez-Hernandez, Julio C., et al.
(författare)
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Diet selectivity in relation to food quality and availability by the endemic Perote squirrel (Xerospermophilus perotensis)
- 2018
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Ingår i: Therya. - Colonia Villa Quietud, Mexico : Asociacion Mexicana de Mastozoologia A.C.. - 2007-3364. ; 9:2, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- Climatic fluctuations have a biogeochemical effect on food availability and quality, resulting in adjustments of the foraging and food selection behavior of animals. Our study aimed to evaluate the influence of seasonal variation on abundance of food resources and its effect on food selection of Xerospermophilus perotensis, an endemic species of ground squirrel in the Oriental Basin. Food selection behavior was recorded using focal animal and continuous behavior sampling on a squirrel population inhabiting the grassland of a semi-arid area. The results show that their diet consisted of 6 plant species with significant differences in the time spent feeding on each plant species (X2 = 128.96; P = 0.01). The species with the highest feeding times included Scleropogon brevifolius (63.6 %), Verbena bipinnatifida (10.6 %) and Erigeron pubescens (10.5 %). These plant species had the highest percentage of vegetation cover and availability among seasons, but they were of low nutritional quality with regard to their protein/fiber ratio. However, during specific periods, associated either with gestation and lactation or prior to hibernation, the squirrels increased their protein consumption. This suggests that squirrels are opportunistic feeders, and under certain conditions tend to select plant species that provide them with better quality diets.
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| 2. |
- 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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| 3. |
- Lahger, Christian, et al.
(författare)
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Behavioral responses of CD-1 mice to conspecific and heterospecific blood odors and to a blood odor component
- 2018
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Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 184, s. 205-210
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Tidskriftsartikel (refereegranskat)abstract
- The odor of blood may have both aversive and attractive properties for mammals, depending on the species of the odor donor and the species perceiving the odor. To better understand the informational content of blood odor for a prey species we assessed behavioral responses of male CD-1 mice (n = 60) to the odor of blood of same-sex and opposite-sex conspecifics, of a natural predator of mice (cat), and of a herbivore (horse) and an omnivore (human) non-predator of mice. Further, we assessed their behavior towards the mammalian blood odor component trans-4,5-epoxy-(E)-2-decenal which recent studies have shown to be as attractive to mammalian predators as the odor of real blood. A two-compartment test arena was used to record approach/avoidance behavior when the animals were presented with an odor in one compartment and a blank control in the other compartment. We found that both conspecific and heterospecific blood odors elicited significant avoidance behavior in the mice whereas a control odor (n-pentyl acetate) did not. The blood odor component trans-4,5-epoxy-(E)-2-decenal was also significantly avoided and thus appears to play an important role in the perception of mammalian blood odor in this prey species. These results support the notion that mammalian blood odor contains an olfactory warning signal which elicits an adaptive behavioral avoidance response in a prey species, the mouse. Our finding that the mice avoided the mammalian blood odor component trans-4,5-epoxy-(E)-2-decenal to the same degree as the odor of real blood suggests that this volatile compound might be (part of) this warning signal.
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| 4. |
- 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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| 5. |
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| 6. |
- 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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| 7. |
- 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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| 8. |
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| 9. |
- 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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| 10. |
- 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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