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  • 1
    ISSN: 1573-1561
    Keywords: Rhagoletis pomonella ; Diptera ; Tephritidae ; fruit volatiles ; visual response ; olfaction ; behavior ; response distance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mature female apple maggot flies,Rhagoletis pomonella (Walsh), were released individually onto a single potted, fruitless hawthorne tree in the center of an open field. The tree was surrounded by four 1-m2 plywood host tree models painted green or white, with or without synthetic host fruit odor (butyl hexanoate), and placed at one of several distances from the release tree. Each fly was permitted to forage freely on the release tree for up to 1 hr, or until it left the tree. Flies left the tree significantly sooner when green models with host fruit were present at 0.5, 1.5, or 2.5 m distance from the release tree than when these models were placed at a greater distance (4.5 m) from the release tree or when no models were present. Flies responded detectably to 1-m2 models without odor up to a maximum distance of 1.5 m. These results suggest that female apple maggot flies did not detect green 1-m2 models with odor 4.5 m away or models without odor 2.5 m or more away. Flies responded to white models with and without odor to a much lesser extent, both in terms of response distance and flight to and alightment upon models. Increasing model size to 2 m2 increased the distance to 2.5 m at which flies responded to green models without odor. Decreasing model size to 0.5 m2 reduced fly responsiveness to green or white models. The presence of host fruit odor alone, without the visual stimulus of a green model, did not influence residence time on the release tree.
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  • 2
    ISSN: 1573-1561
    Keywords: Plum curculio ; Conotrachelus nenuphar (Herbst) ; Coleoptera ; Curculionidae ; oviposition ; host discrimination ; host location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larval survival of plum curculios (PCs),Conotrachelus nenuphar (Herbst), was found to decrease with increasing egg density per fruit. Subsequently, we assayed PCs for propensity to avoid egg-laying at sites (immature plums) already occupied by conspecific eggs. Laboratory choice tests showed PCs made an equal number of visits to and ovipositions in fruit with a single oviposition as in clean fruit. Although there was a trend toward more visits to fruit which contained four or eight oviposition wounds and eggs or eight artificial punctures than to clean fruit, PCs oviposited less frequently into these than clean fruit. Results suggest that wounding of fruit may enhance the ability of ovipositing PCs to locate fruit, but at the same time may furnish cues allowing some degree of discrimination against heavily infested fruit for oviposition.
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  • 3
    ISSN: 1572-8889
    Keywords: Dacus dorsalis ; learning ; foraging ; oviposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mature oriental fruit fly females, Dacus dorsalis, from a population cultured on host fruit in the laboratory for one generation responded positively to visual and olfactory stimuli of individual natural kumquat (Fortunella japonica) and apple (Malus pumila) host fruit or models of these fruit hung from branches of potted trees in field enclosures. When females were exposed for 3 days to natural kumquats or apples on trees and subsequently released individually onto trees harboring one or the other of these fruit types, a significantly greater proportion of those exposed to kumquats than those exposed to apples or those not exposed to any fruit visited kumquats. Females exposed to kimquats for at least 3 days followed by at least 3 days of exposure to apples retained ability to find kumquats. Compared with females exposed to apples for 3 days or with naive females, females exposed to kumquats for 3 days exhibitied no less ability to find apples but did significantly refrain from accepting apples for oviposition. A final test was conducted in which females were exposed to natural kumquats or apples for 3 days and tested for response to inanimate models of either the same color and size as natural kumquats (orange, 20-mm diameter) or apples (green, 75-mm diameter) or models of the same color but opposite size. Results suggest that fruit size is the principal character learned and used in finding kumquats, which apparently are somewhat inconspicuous to an inexperienced foraging D. dorsalisfemale.
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  • 4
    ISSN: 1570-7458
    Keywords: Ceratitis capitata ; learning ; foraging ; oviposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des femelles sauvages d'une population essentiellement monophage de C. capitata Wiedemann, provenant de l'île de Hawaï, ont été mises en présence pendant des périodes de 3 jours dans des enceintes dans la nature à des fruits de Murraya paniculata et de Citrus sinensis suspendus à des branches d'arbres empotés. Quand les mouches ont été libérées individuellement sur les arbres empotés portant l'un ou l'autre de ces fruits (ou leur mélange), une plus forte proportion a visité le fruit avec lequel elles étaient familiarisées (et l'ont trouvé plus vite) que le fruit avec lequel elles ne n'étaient pas. De plus, les femelles découvrant des fruits de cette population monophage ne tentèrent de pondre que dans le type de fruit avec lequel elle étaient familiarisées. Elles se montrèrent aussi capables que les mouches d'une population polyphage de l'île de Maui d'apprendre à accepter de nouveaux fruits pour pondre. Des expériences complémentaires ont été réalisées dans lesquelles les mouches étaient mises en présence de fruits de M. paniculata ou de C. sinensis naturels ou couverts de cire colorée ou encore de fruits artificiels. Les résultats suggèrent que la taille du fruit est le principal critère d'apprentissage utilisé pour trouver M. paniculata ou C. sinensis, la couleur et l'odeur du fruit étant apparus comme de moindre importance ou sans effet.
    Notes: Abstract Wild Mediterranean fruit fly females, Ceratitis capitata (Wiedemann), from an essentially monophagous population on the island of Hawaii were exposed to natural mock orange (Murraya paniculata) or sweet orange (Citrus sinensis) host fruit hung from branches of potted trees for 3-day periods in field enclosures. Subsequently, when flies were released individually onto potted trees harboring one or the other (or a mixture) of these fruit types, a higher proportion visited the type of fruit with which they were familiar (and visitors found familiar fruit faster) compared with the fruit type with which they were unfamiliar. Moreover, fruit-finding flies of this monophagous population attempted oviposition exclusively in the familiar fruit type, and thus appeared to be just as capable of learning to accept fruit for oviposition as wild flies from a previously-tested polyphagous population on the island of Maui. Additional tests were conducted in which flies were exposed to natural or colored-wax-covered mock oranges or sweet oranges and tested for response to colored-wax-covered natural or artificial fruit. Results suggested that fruit size was the principal character learned and used in finding mock orange or sweet orange fruit, while fruit color and odor appeared to be of little or no importance in this regard.
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  • 5
    ISSN: 1432-2072
    Keywords: Key words Dopamine ; Microdialysis ; Nucleus accumbens ; Feeding ; Locomotion ; Area under the curve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The intent of the present study was to determine the effects of systemic injections of the sympathomimetic agent ephedrine (EPH) on extracellular dopamine (DA) levels within the rat nucleus accumbens (NAC) and to compare these effects with those of EPH on locomotion and on feeding. In experiment 1, adult male rats were prepared with an indwelling 3 mm microdialysis probe positioned within the NAC. The rats were injected (IP) with vehicle, 5, 10, or 20 mg/kg (–)-EPH with dialysates collected every 20 min for 100 min after drug injection. Systemic injections of 5, 10 or 20 mg/kg (–)-EPH significantly enhanced extracellular levels of NAC DA over baseline by 79%, 130%, and 400%. Systemic injection of 20 mg/kg EPH significantly reduced NAC levels of DOPAC and HVA by 37% and 31%. The effects of EPH on brain dopamine activity were stereospecific given that an additional group of rats injected with 20 mg/kg (+)-EPH exhibited smaller changes in NAC DA (〈25%), DOPAC (〈10%), and HVA levels (〈20%) than did rats injected with 20 mg/kg (–)-EPH. In experiment 2, adult male rats were injected (IP) with 0, 5, 10, or 20 mg/kg (–)-EPH prior to placement in automated activity chambers. Total distance traveled was significantly increased by 10 and 20 mg/kg (–)-EPH, but not by 5 mg/kg (–)-EPH. In experiment 3, adult male rats were injected (IP) with 0, 2.5, 5, or 10 mg/kg (–)-EPH or with 0, 2.5, 5, or 10 mg/kg (+)-EPH prior to a 30-min feeding test. Although each EPH enantiomer decreased feeding, (–)-EPH was more potent in feeding suppression than was (+)-EPH. The present results suggest that EPH may alter locomotion and feeding via an indirect action on brain dopamine activity.
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  • 6
    ISSN: 1432-2072
    Keywords: Key words Cocaine ; Dopamine ; Ephedrine ; Locomotion ; Rat ; Sensitization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Systemic injection of the sympathomimetic agent ephedrine (EPH) stimulates locomotion in drug-naive rats, an effect that may be dependent on the enantiomer of EPH employed [(–)-EPH or (+)-EPH]. The present experiments examined the effects of repeated EPH exposure on locomotion in rats to assess whether these treatments result in drug tolerance or sensitization. In experiment 1, adult male rats were injected once daily with 0, 10, 20, or 40 mg/kg (–)-EPH (IP) on each of 11 days. Locomotor activity was assessed for 60 min after drug injection. Acute exposure to (–)-EPH treatment increased locomotion for animals receiving 20 or 40 mg/kg, and this effect was augmented after 11 days of drug administration. A vehicle-only injection was given to all animals on day 12 to determine the influence of environmental cues on sensitization. On day 13, all rats were injected with 10 mg/kg cocaine HCl to assess whether repeated (–)-EPH exposure produced a cross-sensitization to cocaine (10 mg/kg, IP). Only rats treated repeatedly with 40 mg/kg (–)-EPH exhibited increases in cocaine-stimulated locomotion relative to saline-treated rats. In experiment 2, repeated exposure to (+)-EPH, 40 mg/kg, but not 20 mg/kg, increased activity and demonstrated the development of sensitization. Cross-sensitization to cocaine (10 mg/kg, IP) was not evident following treatment with either concentration of (+)-EPH. There was no evidence that contextual events alone played a role in the effects observed here.
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  • 7
    ISSN: 1432-2072
    Keywords: Key words Nicotine ; Nornicotine ; Behavioral sensitization ; Locomotor activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Rationale: Nicotine, a tobacco alkaloid, is known to be important in the acquisition and maintenance of tobacco smoking. Nornicotine, an active nicotine metabolite, stimulates nicotinic receptors and may produce psychomotor effects similar to nicotine. Objective: The present study determined the effects of acute and repeated administration of nornicotine on locomotor activity and compared its effects with those of nicotine. Methods: R(+)-Nornicotine (0.3–10 mg/kg), S(–)-nornicotine (0.3–10 mg/kg), S(–)-nicotine (0.1–1 mg/kg) or saline was administered s.c. to rats acutely or repeatedly (eight injections at 48-h intervals). Activity was recorded for 50 min immediately after each injection. Results: S(–)-Nicotine produced transient hypoactivity, followed by dose-related hyperactivity. Repeated S(–)-nicotine administration resulted in tolerance to the hypoactivity and sensitization to the hyperactivity. Subsequent testing following a saline injection revealed evidence of conditioned hyperactivity. Acute administration of 0.3 mg/kg or 1 mg/kg R(+)- or S(–)-nornicotine produced no effect. Transient hypoactivity was observed at 3 mg/kg and 10 mg/kg R(+)-nornicotine and at 10 mg/kg S(–)-nornicotine. However, rebound hyperactivity was not observed following acute administration of either nornicotine enantiomer, suggesting that nornicotine-induced psychomotor effects differ qualitatively from those of S(–)-nicotine. Repeated R(+)-nornicotine resulted in tolerance to the transient hypoactivity, however hyperactivity was not observed. Repeated S(–)-nornicotine resulted in tolerance to the hypoactivity and the appearance of hyperactivity. Repeated administration of either nornicotine enantiomer resulted in a dose-dependent alteration in response to a 1 mg/kg S(–)-nicotine challenge, suggesting some commonalities in the mechanism of action. Conclusion: Nornicotine likely contributes to the neuropharmacological effects of nicotine and tobacco use.
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  • 8
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Energy & fuels 5 (1991), S. 609-610 
    ISSN: 1520-5029
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Process Engineering, Biotechnology, Nutrition Technology
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  • 9
    ISSN: 1520-5029
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
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