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Robert J. Blanchard - One of the best experts on this subject based on the ideXlab platform.
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The rat exposure test: a model of mouse defensive behaviors.
Physiology & Behavior, 2004Co-Authors: Mu Yang, Robert J. Blanchard, Hanna Augustsson, Chris M. Markham, David Hubbard, Dylan Webster, Phillip M. Wall, D. Caroline BlanchardAbstract:Abstract In order to facilitate behavioral, and potentially pharmacological, analyses of risk assessment behaviors in mice, a rat exposure test (RET) was devised and evaluated. This test provides a home chamber connected via a tunnel to a rat (predator) exposure area. Familiar substrate is provided to permit burying, and mouse subjects are habituated to the apparatus prior to exposure to an amphetamine-activated rat. In comparison to toy-rat-exposed controls, rat-exposed BALB/c mice showed significantly more risk assessment [stretch attend posture (SAP) and stretch approach], freezing, and avoidance (time in the home chamber), and less time in contact with the wire mesh screen between itself and the threat stimulus. When BALB/c, C57BL/6, CD-1, and Swiss–Webster mice were compared in this test, the two inbred strains (BALB/c and C57BL/6) tended to show more extreme values of particular defensive behaviors, compared to the two outbred strains (Swiss–Webster and CD-1). C57BL/6 mice showed more avoidance and higher levels of SAP, freezing, and burying than BALB/c and more than one or both outbred strains as well. BALB/c mice showed little defensive burying, both in comparison to toy-exposed controls (Experiment 1), and in comparison to the three other strains in Experiment 2. These findings are somewhat at variance with characterizations of anxiety in C57BL/6 and BALB/c mice, based on tests utilizing novel areas and noxious stimuli, suggesting strain differences in defensiveness to such stimuli, compared to Antipredator Defense levels. Nonetheless, with the exception of burying in BALB/c mice, all strains showed all defensive behaviors measured to the rat stimulus. In particular, SAP levels were substantial in all strains tested, suggesting the usefulness of this test in assessment of the role of risk assessment in Defense.
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Benzodiazepine and Serotonergic Modulation of Antipredator and Conspecific Defense
Neuroscience & Biobehavioral Reviews, 1998Co-Authors: D. Caroline Blanchard, Guy Griebel, R. John Rodgers, Robert J. BlanchardAbstract:Abstract BLANCHARD, D. C., G. GRIEBEL, R. J. RODGERS AND R. J. BLANCHARD. Benzodiazepine and serotonergic modulation of Antipredator and conspecific Defense . NEUROSCI BIOBEHAV REV 22 (5) 597–612.—The mammalian Defense repertory comprises an array of individual behaviors that are extraordinarily sensitive to relevant features of the threat stimulus and the situation in which it occurs. In parallel with increasing awareness of the specificity and complexity of defensive behaviors and of their potential relevance to psychopathologies (e.g. anxiety, panic, and depression) is an escalating use of natural threat stimuli such as attacking conspecifics or predators in paradigms aimed at evaluating drug effects on Defense. A review of the literature on benzodiazepine (BZ) and serotonin (5-HT) effects on conspecific and Antipredator Defense, including defensive analgesia, indicates that both types of stimuli elicit a wide array of relevant defensive behaviors. These studies suggest specificity of drug effects on particular behaviors, rather than a general alteration of all aspects of Defense. However, stimulus variability and possible confounding of effects are a considerable problem with conspecific Defense paradigms, while Antipredator paradigms utilizing human experimenters as the predator may be difficult to use with domesticated laboratory animal subjects. In addition, sensitivity to the organization of defensive behaviors and to differences between species in Defense patterns is necessary to adequate interpretation of results. Nonetheless, these paradigms have permitted major advancements in analysis of the behavioral Defense systems and their sensitive use in drug studies will greatly facilitate an understanding of the physiology of Defense.
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A model of 'Antipredator' Defense in Swiss-Webster mice: effects of benzodiazepine receptor ligands with different intrinsic activities.
Behavioural pharmacology, 1995Co-Authors: Guy Griebel, D C Blanchard, A. Jung, Robert J. BlanchardAbstract:A mouse Defense test battery (MDTB) has been designee to assess defensive reactions of Swiss-Webster mice to situations associated with nonpianful threat. When compared to mice approached by a leather glove, animals confronted with an anesthetized or a conscious rat displayed potentiated flight responses and defensive threat/attack reactions, while risk assessment performances were generally similar in all three conditions. Furthermore, escape attempt responses following removal of the stimulus were higher in the conscious rat condition compared to the two other groups. Taken together, these results suggest that flight reactions and defensive threat/attack responses are specific to the rat, and thus indicate that the MDTB may relate to ‘Antipredator’ Defense. In mice confronted with an anaesthetized rat, administration of the benzodiazepine (BZ) receptor full agonist chlordiazepoxide (5–25 mg/kg, i.p., 30 min) and the BZ partial agonist Ro 19–8022 (0.5–2 mg/kg, i.p., 30 min) altered one of two risk assessment measures and inhibited defensibe attack behaviors, but failed to counter the post-predator increase in escape attempts. In addition, Ro 19–8022 also strongly reduced flight responses. The overall behavioral profile suggests a fear/anxiety-reducing action of both drugs. By contrast, administration of the BZ inverse agonist Ro 19–4603 (0.025–0.1 mg/kg, i.p., 30 min) reliably released these defensive responses. Interestingly, the BZ antagonist flumazeni (5–20 mg/kg, i.p., 30 min) manifested differential intrinsic activity depending upon the level of threat. Thus, in a weakly threatening situation, the drug potentiated flight reactions, indicating an inverse agonist-like action, decreased defensive biting in a highly threatening situation, indicating an agonist activity. These findings demonstrated that BZ ligands differently modulated ‘Antipredator’ Defense in Swiss Webster mice, depending upon their intrinsic (positive or negative) efficacy, but also depending upon the Defense strategy required by the threat.
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Behaviors of Swiss-Webster and C57/BL/6N sin mice in a fear/Defense test battery
Aggressive Behavior, 1995Co-Authors: Robert J. Blanchard, Scott M. Weiss, Stefano Parmigiani, Rey Agullana, D. Caroline BlanchardAbstract:When confronted by an approaching threat stimulus (experimenter or laboratory rat), Swiss-Webster mice show initial flight, followed by freezing and defensive vocalization and biting, the latter only when escape is blocked. These Defense patterns resemble those of the wild rat, suggesting that mice of this strain do not show the reductions in flight and defensive threat/attack that are typical of laboratory rats. C57/BL/6N Sin strain mice showed fewer avoidances to an approaching predator, as well as reduced vocalization and defensive biting, a pattern more similar to that of laboratory rats. As with rats, female mice appeared to be more defensive to a predator. The showed greater reactivity to dorsal contact and more frequent defensive biting and jump attacks than males of the same strains. These patterns of defensive behaviors suggest that, although strain differences in Defense are substantial, laboratory mice are suitable for, and may offer several advantages in, the study of the genetic, endocrine, and pharmacological basis of Antipredator Defense
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Paradoxical" effects of morphine on Antipredator Defense reactions in wild and laboratory rats.
Pharmacology biochemistry and behavior, 1991Co-Authors: D. Caroline Blanchard, Scott M. Weiss, R. John Rodgers, Abraham J. Weatherspoon, Jon K. Shepherd, Robert J. BlanchardAbstract:Abstract In a Fear/Defense Test Battery, measuring defensive reactions to a present, approaching and contacting predator, the highest dose of morphine tested (7.5 mg/kg) reliably reduced vocalization to dorsal contact, to vibrissae stimulation, and to an anesthetized conspecific in laboratory-bred wild R. norvegicus . Except for a dose-dependent reduction in flinch/jump reactions to dorsal contact (taps), other defensive behaviors (flight, freezing, etc.) were not reliably altered by morphine treatment (0, 1.0, 2.5, 7.5 mg/kg). Vocalization responses to vabrissae stimulation in wild-trapped R. rattus were reliably increased following naloxone (1.0 and 10.0 mg/kg) administration, lending support for opiate receptor involvement in the mediation of defensive vocalization. In the Anxiety/Defense Test Battery, measuring defensive reactions to situations associated with a predator (cat) or with cat odor, laboratory rats showed no decrease in defensive behavior with morphine (0, 1.0, 5.0 mg/kg). In direct contrast to the above findings, the effects of morphine treatment in this test battery suggested a generalized increase in defensiveness to noncontacting and nonpainful threat stimuli. These effects included a decrease in time spent near the cat compartment, with a complementary increase in time spent at maximum distance, a decrease in transits between these sections, an increase in crouching, and a decrease in grooming and rearing. This pattern of results suggests that morphine may have two opposing effects of defensive behavior, a generalized enhancement, together with a more specific reduction of responses to tactile or painful stimulation. A very widespread pattern of reliable sex or sex × drug effects in the Anxiety/Defense Test Battery was in good agreement with previous report of sex differences in these tests, with females generally more defensive than males. Consonant with previous findings, no reliable sex differences were found with the Fear/Defense Test Battery, although several values approached an acceptable level of statistical significance.
D. Caroline Blanchard - One of the best experts on this subject based on the ideXlab platform.
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The rat exposure test: a model of mouse defensive behaviors.
Physiology & Behavior, 2004Co-Authors: Mu Yang, Robert J. Blanchard, Hanna Augustsson, Chris M. Markham, David Hubbard, Dylan Webster, Phillip M. Wall, D. Caroline BlanchardAbstract:Abstract In order to facilitate behavioral, and potentially pharmacological, analyses of risk assessment behaviors in mice, a rat exposure test (RET) was devised and evaluated. This test provides a home chamber connected via a tunnel to a rat (predator) exposure area. Familiar substrate is provided to permit burying, and mouse subjects are habituated to the apparatus prior to exposure to an amphetamine-activated rat. In comparison to toy-rat-exposed controls, rat-exposed BALB/c mice showed significantly more risk assessment [stretch attend posture (SAP) and stretch approach], freezing, and avoidance (time in the home chamber), and less time in contact with the wire mesh screen between itself and the threat stimulus. When BALB/c, C57BL/6, CD-1, and Swiss–Webster mice were compared in this test, the two inbred strains (BALB/c and C57BL/6) tended to show more extreme values of particular defensive behaviors, compared to the two outbred strains (Swiss–Webster and CD-1). C57BL/6 mice showed more avoidance and higher levels of SAP, freezing, and burying than BALB/c and more than one or both outbred strains as well. BALB/c mice showed little defensive burying, both in comparison to toy-exposed controls (Experiment 1), and in comparison to the three other strains in Experiment 2. These findings are somewhat at variance with characterizations of anxiety in C57BL/6 and BALB/c mice, based on tests utilizing novel areas and noxious stimuli, suggesting strain differences in defensiveness to such stimuli, compared to Antipredator Defense levels. Nonetheless, with the exception of burying in BALB/c mice, all strains showed all defensive behaviors measured to the rat stimulus. In particular, SAP levels were substantial in all strains tested, suggesting the usefulness of this test in assessment of the role of risk assessment in Defense.
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Benzodiazepine and Serotonergic Modulation of Antipredator and Conspecific Defense
Neuroscience & Biobehavioral Reviews, 1998Co-Authors: D. Caroline Blanchard, Guy Griebel, R. John Rodgers, Robert J. BlanchardAbstract:Abstract BLANCHARD, D. C., G. GRIEBEL, R. J. RODGERS AND R. J. BLANCHARD. Benzodiazepine and serotonergic modulation of Antipredator and conspecific Defense . NEUROSCI BIOBEHAV REV 22 (5) 597–612.—The mammalian Defense repertory comprises an array of individual behaviors that are extraordinarily sensitive to relevant features of the threat stimulus and the situation in which it occurs. In parallel with increasing awareness of the specificity and complexity of defensive behaviors and of their potential relevance to psychopathologies (e.g. anxiety, panic, and depression) is an escalating use of natural threat stimuli such as attacking conspecifics or predators in paradigms aimed at evaluating drug effects on Defense. A review of the literature on benzodiazepine (BZ) and serotonin (5-HT) effects on conspecific and Antipredator Defense, including defensive analgesia, indicates that both types of stimuli elicit a wide array of relevant defensive behaviors. These studies suggest specificity of drug effects on particular behaviors, rather than a general alteration of all aspects of Defense. However, stimulus variability and possible confounding of effects are a considerable problem with conspecific Defense paradigms, while Antipredator paradigms utilizing human experimenters as the predator may be difficult to use with domesticated laboratory animal subjects. In addition, sensitivity to the organization of defensive behaviors and to differences between species in Defense patterns is necessary to adequate interpretation of results. Nonetheless, these paradigms have permitted major advancements in analysis of the behavioral Defense systems and their sensitive use in drug studies will greatly facilitate an understanding of the physiology of Defense.
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Behaviors of Swiss-Webster and C57/BL/6N sin mice in a fear/Defense test battery
Aggressive Behavior, 1995Co-Authors: Robert J. Blanchard, Scott M. Weiss, Stefano Parmigiani, Rey Agullana, D. Caroline BlanchardAbstract:When confronted by an approaching threat stimulus (experimenter or laboratory rat), Swiss-Webster mice show initial flight, followed by freezing and defensive vocalization and biting, the latter only when escape is blocked. These Defense patterns resemble those of the wild rat, suggesting that mice of this strain do not show the reductions in flight and defensive threat/attack that are typical of laboratory rats. C57/BL/6N Sin strain mice showed fewer avoidances to an approaching predator, as well as reduced vocalization and defensive biting, a pattern more similar to that of laboratory rats. As with rats, female mice appeared to be more defensive to a predator. The showed greater reactivity to dorsal contact and more frequent defensive biting and jump attacks than males of the same strains. These patterns of defensive behaviors suggest that, although strain differences in Defense are substantial, laboratory mice are suitable for, and may offer several advantages in, the study of the genetic, endocrine, and pharmacological basis of Antipredator Defense
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Paradoxical" effects of morphine on Antipredator Defense reactions in wild and laboratory rats.
Pharmacology biochemistry and behavior, 1991Co-Authors: D. Caroline Blanchard, Scott M. Weiss, R. John Rodgers, Abraham J. Weatherspoon, Jon K. Shepherd, Robert J. BlanchardAbstract:Abstract In a Fear/Defense Test Battery, measuring defensive reactions to a present, approaching and contacting predator, the highest dose of morphine tested (7.5 mg/kg) reliably reduced vocalization to dorsal contact, to vibrissae stimulation, and to an anesthetized conspecific in laboratory-bred wild R. norvegicus . Except for a dose-dependent reduction in flinch/jump reactions to dorsal contact (taps), other defensive behaviors (flight, freezing, etc.) were not reliably altered by morphine treatment (0, 1.0, 2.5, 7.5 mg/kg). Vocalization responses to vabrissae stimulation in wild-trapped R. rattus were reliably increased following naloxone (1.0 and 10.0 mg/kg) administration, lending support for opiate receptor involvement in the mediation of defensive vocalization. In the Anxiety/Defense Test Battery, measuring defensive reactions to situations associated with a predator (cat) or with cat odor, laboratory rats showed no decrease in defensive behavior with morphine (0, 1.0, 5.0 mg/kg). In direct contrast to the above findings, the effects of morphine treatment in this test battery suggested a generalized increase in defensiveness to noncontacting and nonpainful threat stimuli. These effects included a decrease in time spent near the cat compartment, with a complementary increase in time spent at maximum distance, a decrease in transits between these sections, an increase in crouching, and a decrease in grooming and rearing. This pattern of results suggests that morphine may have two opposing effects of defensive behavior, a generalized enhancement, together with a more specific reduction of responses to tactile or painful stimulation. A very widespread pattern of reliable sex or sex × drug effects in the Anxiety/Defense Test Battery was in good agreement with previous report of sex differences in these tests, with females generally more defensive than males. Consonant with previous findings, no reliable sex differences were found with the Fear/Defense Test Battery, although several values approached an acceptable level of statistical significance.
Tim Caro - One of the best experts on this subject based on the ideXlab platform.
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Flash behavior in mammals?
Behavioral Ecology and Sociobiology, 2020Co-Authors: Tim Caro, Hana Raees, Theodore StankowichAbstract:Conspicuous coloration in animals has many possible functions including signaling to conspecifics, or predator deterrence through confusion, intimidation, and duping; the last includes flash behavior where predators are deceived into looking for conspicuous cues exhibited in flight but that are hidden when the animal comes to rest. In an effort to see if flash behavior occurs in mammals, we made predictions about situations where conspicuous coloration (as based on human assessment) might occur in artiodactyls and lagomorphs, and other predictions as to where such coloration might be found under an intraspecific signaling hypothesis. Using phylogenetically controlled analyses, we found that across species of artiodactyls, conspicuous rumps are more likely to have evolved in larger-sized group-living species supporting an intraspecific signaling function; this was not replicated in lagomorphs. Examining those artiodactyls that can facultatively expose color patches (putative flash behavior), we discovered that this trait occurred in artiodactyls that are solitary or living in very small groups irrespective of their body size. It is therefore possible that species such as white- and black-tailed deer, which display white rumps and tails during pursuit but hide them when stationary, are using flash behavior to confuse the predator into looking for the wrong object and thereby avoid detection and suggests that this form of Antipredator Defense in mammals needs greater attention. We found no effects of group size or body mass on conspicuous tail or ear markings in these taxa. Significance statement Many mammals have conspicuous markings on their appendages and hindquarters, the function of which is mostly unknown. We matched these markings in rabbits, hares, and pikas and in bovids and cervids to both body size and group size across species. We found that conspicuous rumps are found in group living ungulates but when we separated these into conspicuous hindquarters always on display or that could be hidden, we found that hidden markings were principally found in species living alone or in very small groups irrespective of their body size. These species may expose conspicuous patches during flight but hide them at rest fooling the predator into searching for the wrong object, a relatively newly researched Defense mechanism called flash behavior.
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Flash behavior increases prey survival
Behavioral Ecology, 2018Co-Authors: Karl Loeffler-henry, Tim Caro, Changku Kang, Yolanda Yip, Thomas N. SherrattAbstract:Flash behavior is an Antipredator Defense in which an otherwise cryptic prey displays conspicuous color patches during its escape but hides them on resettling. Using human subjects, we found that flash behavior increased the survival rate of escaping artificial prey, most likely because subjects expected to see prey of a different appearance when they came to search for them. This study provides first proof of concept of one hypothesized benefit of flash behavior.
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Antipredator deception in terrestrial vertebrates
Current Zoology, 2014Co-Authors: Tim CaroAbstract:Deceptive Antipredator Defense mechanisms fall into three categories: depriving predators of knowledge of prey's presence, providing cues that deceive predators about prey handling, and dishonest signaling. Deceptive Defenses in terrestrial vertebrates include aspects of crypsis such as background matching and countershading, visual and acoustic Batesian mimicry, active Defenses that make animals seem more difficult to handle such as increase in apparent size and threats, feigning injury and death, distractive behaviours, and aspects of flight. After reviewing these Defenses, I attempt a preliminary evaluation of which aspects of Antipredator deception are most widespread in amphibians, reptiles, mammals and birds (Current Zoology 60 (1): 16 25, 2014).
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Are spotted skunks conspicuous or cryptic
Ethology Ecology & Evolution, 2013Co-Authors: Tim Caro, Theodore Stankowich, Christian Kiffner, Jennifer S. HunterAbstract:Aposematism and crypticity are viewed as mutually exclusive Antipredator Defense strategies with skunks being a classic example of the former. Skunks can spray noxious anal secretions and many species (Conepatus and Mephitis spp.) have bold blocks of white fur on black pelage, but spotted skunks (Spilogale sp.) have white spots and lines on a black coat suggesting an additional function. We tested the possibility that spotted skunks are conspicuous at close range but cryptic at a distance. Using quantitative measures of colouration extracted from photographs of taxidermied western spotted skunk, bobcat and striped skunk mounts taken at ≤ 5 m, we found that spotted skunk colouration was significantly more conspicuous than the cryptic bobcat but not than the striped skunk. Differences between mount and background colouration were significantly greater for spotted skunks than for bobcats but not for striped skunks. Both sets of results indicate that spotted skunks match their background poorly when viewed cl...
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BOLD COLORATION AND THE EVOLUTION OF APOSEMATISM IN TERRESTRIAL CARNIVORES
Evolution, 2011Co-Authors: Theodore Stankowich, Tim Caro, Matthew CoxAbstract:Several species of terrestrial carnivores (Mammalia: Carnivora) have bold contrasting color patterns that, in some species, apparently signal possession of noxious anal gland secretions, or even physical strength and great ferocity; yet the evolutionary drivers of both placement and patterning of these contrasting pelage colors on the body, and the ecological selection pressures underlying them, have yet to be systematically examined. Here we explore these issues and find not only that both boldly colored and dichromatic species do indeed often use anal gland secretions for Defense, but also that such species are stockier, and live in more exposed habitats where other forms of Antipredator Defense are limited. We also show that white dorsa are found in sprayers that are primarily nocturnal; that horizontal stripes are found in species that have an ability to spray anal secretions accurately; and that facial stripes are found in burrowing species that typically leave only their heads exposed to attack. Our phylogenetic reconstructions suggest that aposematic coloration has evolved more than once in terrestrial carnivores. We finish by outlining five evolutionary routes for patterns of pelage coloration in this taxon.
Scott M. Weiss - One of the best experts on this subject based on the ideXlab platform.
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Effects of diazepam and buspirone on the behaviour of wild voles (Microtus socialis) in two models of anxiety.
Pharmacology biochemistry and behavior, 1997Co-Authors: C.a. Hendrie, David Eilam, Scott M. WeissAbstract:Exploration models of anxiety rely almost universally on the use of laboratory species. Furthermore, the spontaneous patterns of locomotion displayed are often interpreted as being an expression of Antipredator Defense. However, there is no direct link between the experience of these animals and the proposed motivation for their behaviour. To address this problem, the behaviour of wild trapped voles (Microtus socialis), a small-rodent species that is heavily predated upon, was examined in the elevated plus-maze and the black/white exploration model. It was hypothesised that the patterns of locomotion in these exploration models of anxiety should be similar to those reported for laboratory animals if the reactions of the laboratory animals are related to Antipredator Defense. Data revealed that voles show a similar preference for the protected areas in these models (closed arms or dark section) and that this preference can be modified by buspirone and diazepam. Interestingly, although the effective doses of each drug was the same within each model, it differed between models, with the minimum effective doses of these compounds being lower in the black/white exploration model (1 mg/kg) than in the elevated plus-maze (4 mg/kg). These data provide valuable information concerning the actions of anxiolytic compounds in wild trapped animals as assessed by formal laboratory models and provide useful verification that findings in these models may be generalised to species other than laboratory rodents.
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Behaviors of Swiss-Webster and C57/BL/6N sin mice in a fear/Defense test battery
Aggressive Behavior, 1995Co-Authors: Robert J. Blanchard, Scott M. Weiss, Stefano Parmigiani, Rey Agullana, D. Caroline BlanchardAbstract:When confronted by an approaching threat stimulus (experimenter or laboratory rat), Swiss-Webster mice show initial flight, followed by freezing and defensive vocalization and biting, the latter only when escape is blocked. These Defense patterns resemble those of the wild rat, suggesting that mice of this strain do not show the reductions in flight and defensive threat/attack that are typical of laboratory rats. C57/BL/6N Sin strain mice showed fewer avoidances to an approaching predator, as well as reduced vocalization and defensive biting, a pattern more similar to that of laboratory rats. As with rats, female mice appeared to be more defensive to a predator. The showed greater reactivity to dorsal contact and more frequent defensive biting and jump attacks than males of the same strains. These patterns of defensive behaviors suggest that, although strain differences in Defense are substantial, laboratory mice are suitable for, and may offer several advantages in, the study of the genetic, endocrine, and pharmacological basis of Antipredator Defense
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Paradoxical" effects of morphine on Antipredator Defense reactions in wild and laboratory rats.
Pharmacology biochemistry and behavior, 1991Co-Authors: D. Caroline Blanchard, Scott M. Weiss, R. John Rodgers, Abraham J. Weatherspoon, Jon K. Shepherd, Robert J. BlanchardAbstract:Abstract In a Fear/Defense Test Battery, measuring defensive reactions to a present, approaching and contacting predator, the highest dose of morphine tested (7.5 mg/kg) reliably reduced vocalization to dorsal contact, to vibrissae stimulation, and to an anesthetized conspecific in laboratory-bred wild R. norvegicus . Except for a dose-dependent reduction in flinch/jump reactions to dorsal contact (taps), other defensive behaviors (flight, freezing, etc.) were not reliably altered by morphine treatment (0, 1.0, 2.5, 7.5 mg/kg). Vocalization responses to vabrissae stimulation in wild-trapped R. rattus were reliably increased following naloxone (1.0 and 10.0 mg/kg) administration, lending support for opiate receptor involvement in the mediation of defensive vocalization. In the Anxiety/Defense Test Battery, measuring defensive reactions to situations associated with a predator (cat) or with cat odor, laboratory rats showed no decrease in defensive behavior with morphine (0, 1.0, 5.0 mg/kg). In direct contrast to the above findings, the effects of morphine treatment in this test battery suggested a generalized increase in defensiveness to noncontacting and nonpainful threat stimuli. These effects included a decrease in time spent near the cat compartment, with a complementary increase in time spent at maximum distance, a decrease in transits between these sections, an increase in crouching, and a decrease in grooming and rearing. This pattern of results suggests that morphine may have two opposing effects of defensive behavior, a generalized enhancement, together with a more specific reduction of responses to tactile or painful stimulation. A very widespread pattern of reliable sex or sex × drug effects in the Anxiety/Defense Test Battery was in good agreement with previous report of sex differences in these tests, with females generally more defensive than males. Consonant with previous findings, no reliable sex differences were found with the Fear/Defense Test Battery, although several values approached an acceptable level of statistical significance.
Bhagyashri A. Shanbhag - One of the best experts on this subject based on the ideXlab platform.
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Tadpoles of the bronze frog (Rana temporalis) assess predation risk before evoking Antipredator Defense behavior
Journal of Ethology, 2012Co-Authors: Santosh M. Mogali, Srinivas K. Saidapur, Bhagyashri A. ShanbhagAbstract:Predation threat-associated behavioral response was studied in Rana temporalis tadpoles to discover the importance of predators’ visual and chemical cues (kairomones and diet-derived metabolites of consumed prey) in evoking Antipredator behavior. The caged predators (dragonfly larvae) fed on prey tadpoles or insects ( Notonecta spp.) and water conditioned with the predators provided the threat stimuli to the tadpole prey. The predators’ visual cues were ineffective in evoking Antipredator behaviors in the tadpole prey. However, exposure to caged tadpole-fed predators or water conditioned with tadpole-fed predators elicited predator avoidance behavior in the tadpoles; they stayed away from the predators, significantly reduced swimming activity (swimming time and distance traveled), and increased burst speed. Interestingly, exposure to water conditioned with starved predators did not elicit any Antipredator behavior in the prey. Further, the Antipredator responses of predator-experienced tadpoles were significantly greater than those exhibited by predator-naïve tadpoles. The study shows that R. temporalis tadpoles assess predation threat based exclusively on chemical cues emanating from the predators’ dietary metabolites and that the inclusion of conspecific prey items in the diet of the predators is perceived as a threat. The study also shows that Antipredator behavior in these tadpoles is innate and is enhanced during subsequent encounters with the predators.
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Levels of Predation Modulate Antipredator Defense Behavior and Metamorphic Traits in the Toad Bufo melanostictus
Journal of Herpetology, 2011Co-Authors: Santosh M. Mogali, Srinivas K. Saidapur, Bhagyashri A. ShanbhagAbstract:The influence of the presence of nonlethal predators on Antipredator Defense behavior and metamorphic traits was studied in the toad Bufo melanostictus. Tadpoles reared with caged predaceous tadpoles of Hoplobatrachus tigerinus delayed metamorphosis and also emerged at a smaller size compared to those in a predator-free environment. Different predaceous cues (kairomones, alarm cues and dietary cues, derived after feeding the predator with conspecific prey) induced increase in stationary phase and swimming speed and decrease in swimming spurts and time used for feeding. The intensity of Defense behaviors varied with the cue. They were more intense in response to cues of predators fed on conspecific prey item. The response to alarm cues or kairomones or predators fed on heterogeneric tadpole species was similar but lower in magnitude compared to that elicited in response to predators fed on conspecific prey item. Most intense Defense behavior in response to the odors of the predator that consumed conspecific members is possibly caused by a combined effect of kairomones, alarm, and dietary cues. The findings suggest that B. melanostictus tadpoles are capable of assessing levels of predation risk and modulating the intensity of their Defense behavior in accordance with the perceived threat. Interestingly, despite longer larval period, size at metamorphosis of the toadlets was smaller in the presence of caged predator.
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Mechanism of predator–prey detection and behavioral responses in some anuran tadpoles
Chemoecology, 2009Co-Authors: Srinivas K. Saidapur, Dheeraj K. Veeranagoudar, Ningappa C. Hiragond, Bhagyashri A. ShanbhagAbstract:Predator–prey relationship was studied in three sympatric species of anuran tadpoles. The study design consisted of allowing predaceous Hoplobatrachus tigerinus tadpoles to devour prey tadpoles ( Sphaerotheca breviceps and Bufo melanostictus ) placed in a plastic tub (five tadpoles of each species, stage ~27) in 30 min. In trials without refugia, more tadpoles of Bufo fell prey compared to Sphaerotheca . In contrast, provision of refugia using hydrilla plant reversed predation risk of the two species. The swimming speed ( V _max = 64.55 ± 1.45 cm/s) of Hoplobatrachus tadpoles was much higher compared to the prey species ( Bufo : 3.6 ± 0.4 cm/s; Sphaerotheca : 27.6 ± 1.6 cm/s). Poor swimming ability may account for the observed vulnerability of the Bufo tadpoles to predation especially in clear waters; refugia overcame predation to some extent. On the other hand, Sphaerotheca tadpoles that swim faster than the toad tadpoles were less vulnerable in open areas; refugia actually hindered swimming and increased predation. Experiments with association choice tests show that predaceous tadpoles detect prey based on both visual and chemical cues. On the other hand, the prey tadpoles detected predator based exclusively on chemical rather than visual cues. The Antipredator Defense strategy of the toad tadpoles is manifested in the form of reduced movements, remaining still for longer times and, increased burst speed. The present findings also suggest that in both prey species predator detection has a genetic basis since naive tadpoles with no prior exposure to predators exhibit fright response on first encounter with them.
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Activity of Sphaerotheca breviceps tadpoles in response to chemical cues of the predaceous tadpoles Hoplobatrachus tigerinus
Journal of Ethology, 2008Co-Authors: Shruti S. Sharma, Dheeraj K. Veeranagoudar, Bhagyashri A. Shanbhag, Srinivas K. SaidapurAbstract:Tadpoles of Sphaerotheca breviceps raised in the laboratory from the egg stage, and hence lacking prior experience of a predator or its odors, were tested to examine their responses to a predator’s (tadpoles of Hoplobatrachus tigerinus ) water-borne chemical cues. The stimulus solution was obtained following 24 h of rearing tadpoles of H . tigerinus (one tadpole per 200 mL water) that were not fed during this period. Upon exposure to the stimulus solution the activity of S. breviceps tadpoles decreased by about 90% within 5 min. Their resting period increased significantly over baseline activity, whereas the swimming period, distance traversed, and swimming spurts declined. However, whenever a test tadpole moved, its swimming velocity was high in response to stimulus solution. The Antipredatory responses declined with increase in time of storage of the stimulus solution, indicating decay of the predator’s chemical cues. The findings suggest that (1) Antipredator Defense strategies of S. breviceps do not require prior experience of predators, (2) the predator’s chemical cues are labile in nature, and (3) the response of prey tadpoles to such cues is similar to reported behavior of anuran tadpoles in response to real predators and alarm cues.
