Robert J Blanchard

Robert J Blanchard
University of Hawaiʻi at Mānoa | UH Manoa · Pacific Biosciences Research Center

Phd

About

305
Publications
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24,359
Citations
Citations since 2017
1 Research Item
4903 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800

Publications

Publications (305)
Article
This study investigated the influence of the estrus cycle in mediating cat odor-induced unconditioned and conditioned defensive behaviors in female Long-Evans hooded rats. Unconditioned defensive behaviors were assessed during predatory cue exposure; conditioned defensive behaviors were examined 24 h after threat exposure. Estrus phases were determ...
Article
Full-text available
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized, in part, by an inability to adequately respond to social cues. Patients diagnosed with ASD are often devoid of empathy and impaired in understanding other people's emotional perspective. The neuronal correlates of this impairment are not fully understood. Replicating suc...
Chapter
When a predator attacks, prey are faced with a series of 'if', 'when' and 'how' escape decisions – these critical questions are the foci of this book. Cooper and Blumstein bring together a balance of theory and empirical research to summarise over fifty years of scattered research and benchmark current thinking in the rapidly expanding literature o...
Article
Thirty-two albino rats, under no deprivation or under severe food deprivation, were given 10 series of 12 different shock intensities, using the method of constant stimuli. Their reactions were classified into several categories. For the vocalization category, thresholds were significantly higher for the deprived group while no differences were obt...
Article
Binary stimulus dimensions of duration, laterality, frequency, amplitude, and number were compared for their respective information values in auditory concept identification of males and females. Amplitude, without irrelevant information, was shown to provide significantly less information than the other dimensions with the exception of number. Mal...
Article
Step-in latencies and the proportion of time spent outside the shock situation were measured for three groups of rats. One group had received shock on stepping into the shock chamber, and had been allowed to escape the shock chamber. A yoked control group received the same number of shocks after being placed directly into the shock chamber. Escape...
Article
Seven days after receiving unavoidable shock, rats were placed in the shock chamber, or in an adjacent chamber. Free access between the chambers was permitted, and latency to cross was measured. Latency to cross into the shocked chamber was an increasing function of shock intensity, while latency to escape the shock chamber was not related to the i...
Article
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In contrast to enucleation or deafening, olfactory bulbectomy increases mouse-killing in rats. Mice coated with lavender oil are killed more frequently by intact rats. These and previous experiments indicate that olfactory bulbectomy releases an inhibition of mouse killing in the rat and suggest a specific mechanism for such inhibition.
Article
Two groups of rats were given seven brief foot shocks at 1 h intervals. The Ss who had been placed in the shock situations 24 h before shock crouched less after the second and all succeeding shocks than the group which had only 1/2 h habituation to the shock situation, thus indicating that the cues of the shock situation influence postshock crouchi...
Article
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Cholinergic stimulation of the lateral hypothalamus of the rat was found to produce a reliable increment in drinking and home cage activity, and a reduction in sleeping. These results support the suggestion that the rat and the cat differ with respect to their reactions to lateral hypothalamic sumulation. Also, the hyperactivity accompanying cholin...
Article
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A film analysis of fighting and nonfighting episodes in a shock-elicited fighting task indicated an almost total absence of behaviors typical of the attack pattern of dominant colony rats on intruders. The most frequent “fighting” response seen was striking, a forelimb movement oriented toward the opponent. However, forelimb movements identical exc...
Article
A time-sampling procedure was used to study the behavior of rats following a single foot shock. The Ss who received a 2 sec, 1.3 mA shock crouched more, lay down less, and were initially less active, than nonshocked controls. Crouching differences were greatest during the first 30 min after shock, and declined systematically over a 3 h period. The...
Article
Corticotropin-releasing factor (CRF) plays an essential role in coordinating the autonomic, endocrine and behavioral responses to stressors. In this study, we investigated the role of CRF within the medial prefrontal cortex (mPFC) in modulating unconditioned defensive behaviors, by examining the effects of microinfusing cortagine a selective type-1...
Article
Female rats received shock through objects varying in discriminability. Poorly discriminable objects elicited rapid avoidance acquisition, with suppression of activity and subsequent avoidance of the shock chamber (increased entry latencies). Highly discriminable shock objects also elicited rapid acquisition of avoidance, but without activity suppr...
Article
Thirty-two rats, under no deprivation or under 48 h water deprivation, were given 10 series of 12 different shock intensities, using the method of constant stimuli. Their reactions were classified into several categories. None of the group differences on these categories approached statistical significance, indicating that water deprivation does no...
Article
Full-text available
Sexually experienced male rats, injected intranasally with ZnSO4 solution, showed decreased social investigation toward juvenile and adult conspecifics of either sex, when tested 2 months posttreatment. Saline-treated control males exhibited levels of social-investigatory behavior toward juveniles similar to those displayed toward adult nonreceptiv...
Article
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Abnormal cellular growth and organization have been characterized in postmortem tissue from brains of autistic individuals, suggestive of pathology in a critical neurogenic niche, the subventricular zone (SVZ) of the brain lateral ventricles (LV). We examined cellular organization, cell proliferation, and constituents of the extracellular matrix su...
Article
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The development of tasks measuring behaviors specific to the three major symptom categories for autism makes it possible to differentiate mouse models of autism spectrum disorders (ASD) in terms of changes in these specific categories. Prior studies indicate that BTBR T+tf/J mice, the strain that has been evaluated most extensively, show autism-rel...
Article
Full-text available
Autism spectrum disorders (ASD) form a common group of neurodevelopmental disorders appearing to be under polygenic control, but also strongly influenced by multiple environmental factors. The brain mechanisms responsible for ASD are not understood and animal models paralleling related emotional and cognitive impairments may prove helpful in unrave...
Article
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A major goal of translation research in autism is to characterize the physiological and psychological processes underlying behavioral abnormalities. Since autism reflects impairments in social motivation, we modified the mouse three-chamber social approach apparatus for use as a social conditioned place preference arena. We paired one of two unique...
Article
Clinical studies have shown that children diagnosed with autism show abnormal sulfate chemistry, which is critical for cellular and metabolic processes. To determine if the inbred BTBR T+tf/J mouse shows autism-relevant aberrations in sulfate chemistry, the present study examined plasma sulfate concentrations in BTBR T+tf/J, inbred C57BL/6J, and ou...
Article
Some animals display a variety of context dependent facial expressions. Previous studies have shown that rodents display a facial grimace while in pain. To determine if the facial expressions of mice extend beyond pain, facial expressions were analyzed in the presence of non-social, social and predator stimuli. In a vibrissae contact test, the whis...
Article
Full-text available
BTBR T+tf/J (BTBR) mice show abnormal social, communicatory, and repetitive/stereotyped behaviors paralleling many of the symptoms of autism spectrum disorders. BTBR also show agenesis of the corpus callosum (CC) suggesting major perturbations of growth or guidance factors in the dorsal forebrain [1]. Heparan sulfate (HS) is a polysaccaride found i...
Article
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A wealth of studies has implicated oxytocin (Oxt) and its receptors (Oxtr) in the mediation of social behaviors and social memory in rodents. It has been suggested that failures in this system contribute to deficits in social interaction that characterize autism spectrum disorders (ASD). In the current analyses, we investigated the expression of au...
Article
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Mouse models of Rett syndrome, with targeted mutations in the Mecp2 gene, show a high degree of phenotypic consistency with the clinical syndrome. In addition to severe and age-specific regression in motor and cognitive abilities, a variety of studies have demonstrated that Mecp2 mutant mice display impaired social behavior. Conversely, other studi...
Article
BTBR T+tf/J (BTBR) mice have emerged as strong candidates to serve as models of a range of autism-relevant behaviors, showing deficiencies in social behaviors; reduced or unusual ultrasonic vocalizations in conspecific situations; and enhanced, repetitive self-grooming. Recent studies have described their behaviors in a seminatural visible burrow s...
Article
Previous findings point to the involvement of the dorsal raphe nucleus (DRN) and dorsal periaqueductal gray (dPAG) serotonergic receptors in the mediation of defensive responses that are associated with specific subtypes of anxiety disorders. These studies have mostly been conducted with rats tested in the elevated T-maze, an experimental model of...
Article
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BTBR T+ tf/J (BTBR) is an inbred mouse strain that shows behavioral traits with analogies to the three diagnostic symptoms of autism spectrum disorder (ASD); deficits in social interaction, impaired communication, and repetitive behaviors with restricted interests. Previous findings reveal that when compared to C57BL/6J (B6) and other inbred strain...
Article
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The core symptoms of autism spectrum disorder (ASD) include deficits in social interaction, impaired communication, and repetitive behaviors with restricted interests. Mouse models with behavioral phenotypes relevant to these core symptoms offer an experimental approach to advance the investigation of genes associated with ASD. Previous findings de...
Article
Intracerebroventricular (i.c.v.) or intraperitoneal (IP) administration of saredutant (SR48968), an NK2 receptor antagonist, produces anxiolytic-like effects in rodents in a number of animal models of anxiety. NK2 binding sites are present in several limbic structures in rats, including the hippocampus, thalamus, septum and prefrontal cortex, sugge...
Article
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The BTBR T+ tf/J (BTBR) inbred mouse strain displays a low sociability phenotype relevant to the first diagnostic symptom of autism, deficits in reciprocal social interactions. Previous studies have shown that BTBR mice exhibit reduced social approach, juvenile play, and interactive behaviors. The present study evaluated the behavior of the BTBR an...
Article
Full-text available
Risk assessment is a pattern of activities involved in detection and analysis of threat stimuli and the situations in which the threat is encountered. It is a core process in the choice of specific defenses, such as flight, freezing, defensive threat and defensive attack, that counter the threat and minimize the danger it poses. This highly adaptiv...
Article
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The BTBR T+tf/J inbred mouse strain displays a variety of persistent phenotypic alterations similar to those exhibited in autism spectrum disorders (ASDs). The unique genetic background of the BTBR strain is thought to underlie its lack of reciprocal social interactions, elevated repetitive self-directed grooming, and restricted exploratory behavio...
Article
CRF receptor subtype 1 (CRF1), abundantly expressed in the central nervous system, has been implicated in defensive behavior in rodents. Pharmacological activation of CRF1 by peptidic agonists results in enhancement of anxiety-like behavior. However, receptor specificity of commonly used agonists was confounded by significant affinity to other rece...
Article
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Laboratory models of neurodevelopmental disorders may be useful in assessing investigation and preference for social partners in mice. One such mouse model, the three-chamber test, is increasingly used as an index of social preference. The first phase measures preference for a social stimulus over an identical chamber without a stimulus mouse. The...
Article
Early-life stress produces an anxiogenic profile in adulthood, presumably by activating the otherwise quiescent hypothalamic-pituitary-adrenal (HPA) axis during the vulnerable 'stress hyporesponsive period'. While the long-term effects of such early-life manipulations have been extensively characterized, little is known of the short-term effects. H...
Article
The stressors that humans typically face in the modern, developed world originate largely from social and interpersonal interactions, rather than from physical stressors. These social stressors have been modeled in the laboratory in a variety of different ways, including acute or chronic defeat, social subordination, social instability, crowding, a...
Article
Defensive behaviors are evolved responses to threat, common to most mammalian species. Specific defenses may be differentiated anatomically at some brain sites and by responsivity to antianxiety drugs. Over-(or inappropriate) expression of specific defenses may contribute to the phenomenology of particular anxiety disorders.
Chapter
Defensive behaviors are a group of evolved responses to threat. They include flight, freezing, defensive threat, defensive attack, and risk assessment. The type of defensive behavior elicited in a particular situation depends on features of both the threat and the situation. Although defensive behaviors have a substantial unlearned component, they...
Article
In "Laboratory Rodent Welfare: Thinking Outside the Cage," Balcombe (2010/this issue) suggests that laboratory cage housing is damaging to rats and mice because it does not meet their evolved needs and may damage their psychological and physical health. The article also indicates that larger and more enriched spaces reduce aggression and mortality...
Article
Territorial male mice can form familiarity-dependent amicable relationships, suggesting that they manage their territorial aggressiveness based on individual recognition, which may be mediated by olfactory signals. The present study demonstrated modulatory effect of odorant cues from mice of different social/housing groups on territorial scent mark...
Article
This study investigated a possible role for ventral hippocampal corticotropin-releasing factor (CRF) in modulating both unconditioned and conditioned defensive behaviors by examining the effects of pre-training ventral hippocampal ovine-CRF (oCRF) or acidic-astressin ([Glu11,16]Ast) microinfusions in male Long-Evans hooded rats exposed to various t...
Article
Mice show urinary scent marking behavior as a form of social communication. Marking to a conspecific stimulus mouse or odor varies with stimulus familiarity, indicating discrimination of novel and familiar animals. This study investigated Fos immunoreactivity in inbred C57BL/6J (C57) males following scent marking behavior in response to detection o...
Article
Impending dangers elicit alarm vocalizations aimed at conspecifics, and these calls in turn elicit defensive responses in recipients. The notion that these vocalizations represent adaptive responses to threat, enhancing the survival and reproduction of potentially-related conspecifics, is supported by findings from laboratory and field studies. The...
Article
Defensive behaviors are a set of responses to threat stimuli and situations that have evolved on the basis of their adaptiveness in reducing harm to the threatened organism. These behaviors are highly conserved across mammals and rapidly conditioned to stimuli and situations associated with threat. Because the effectiveness of particular defenses m...
Chapter
This chapter introduces the concepts surrounding fear and anxiety, and discusses why it is important to study these conditions. Fear is the motivation associated with a number of behaviors that normally occur on exposure to clearly threatening stimuli. Anxiety is the motivation associated with behaviors that occur to potential, signaled or ambiguou...
Article
Preclinical animal models are utilized in the study of unconditioned states related to fear and anxiety. They are used to screen novel pharmaceuticals, study behavioral phenomena, and understand underlying etiology. In this chapter, we will present a brief overview of the most prevalently used models, discuss their various applications, and state t...
Article
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With the advent of functional magnetic resonance imaging (fMRI) in awake animals it is possible to resolve patterns of neuronal activity across the entire brain with high spatial and temporal resolution. Synchronized changes in neuronal activity across multiple brain areas can be viewed as functional neuroanatomical circuits coordinating the though...
Article
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In rodents, where chemical signals play a particularly important role in determining intraspecies interactions including social dominance and intersexual relationships, various studies have shown that behavior is sensitive to conspecific odor cues. Mice use urinary scent marks for communication with individual conspecifics in many social contexts....
Article
Full-text available
Olfaction is a major sensory element in intraspecies recognition and communication in mice. The present study investigated scent marking behaviors of males of the highly inbred C57BL/6J (C57) strain in order to evaluate the ability of these behaviors to provide clear and consistent measures of social familiarity and response to social signals. C57...
Conference Paper
Background: Autism is defined in terms of three symptom groupings; deficiencies in reciprocal social interactions, deficiencies in communication, and the presence of restricted or ritualized behaviors. These three are not well correlated, nor do they necessarily respond similarly to treatment, suggesting that they may be under the control of differ...
Article
This article provides an introduction to the special issue on olfaction and defense-related emotions. Included papers are briefly discussed. This group of studies encompass a number of different types and species of predator odors (cat or ferret fur/skin odor; fox anal gland odor); subject species (mice, rats, people); and behaviors (e.g. defensive...
Article
Intruder and resident male colony mice exhibit an array of distinct defensive and offensive behaviors. Intruders typically show more boxing, flight, defensive sideways position, on the back position and general locomotion, while residents exhibit higher levels of attack, olfactory investigation, aggressive grooming, and biting, with a preference fo...
Article
Rats incorporate circa 22kHz ultrasonic alarm cries into their defense pattern in response to a predator threat. These calls are dependent on conspecific presence, show gender differences, and tend to be emitted from a place of relative safety. Rats emit sonic defensive threat vocalizations when approached by a potential threat. These are emitted r...
Article
Full-text available
The present study investigated urinary scent marking behavior in male C57BL/6J (C57) mice as olfactory social signaling. In Experiment 1, when compared scent marking toward adult males, C57 males showed substantial scent marking toward CD-1 males and even toward the odor alone of CD-1 males, but not toward C57 males. Experiment 2 explored scent mar...
Article
The dorsal periaqueductal gray (dPAG) is involved in defensive coping reactions to threatening stimuli. Corticotropin releasing factor (CRF) is substantially implicated as a direct modulator of physiological, endocrine and behavioral responses to a stressor. Previous findings demonstrate a direct role of the central CRF system in dPAG-mediated defe...
Article
Corticotropin-releasing factor (CRF) is a neuropeptide and mediating component of neuroendocrine, autonomic, and behavioral processes associated with the stress response. The two receptor subtypes identified in the mammalian brain, CRF receptor subtype 1 (CRF1) and CRF2, are suggested to differentially modulate these processes. Manipulation of thes...
Article
The midbrain dorsal periaqueductal gray (DPAG) is part of the brain defensive system involved in active defense reactions to threatening stimuli. Corticotrophin releasing factor (CRF) is a peptidergic neurotransmitter that has been strongly implicated in the control of both behavioral and endocrine responses to threat and stress. We investigated th...
Article
Full-text available
Deficits in social interaction are primary characteristics of autism, which has strong genetic components. Genetically manipulated mouse models may provide a useful research tool to advance the investigation of genes associated with autism. To identify these genes using mouse models, behavioral assays for social relationships in the background stra...
Article
In order to investigate the relationship between behaviors elicited by chemical stimulation of the dorsal periaqueductal gray (dorsal PAG) and spontaneous defensive behaviors to a predator, the excitatory amino acid D,L-homocysteic acid (5 nmol in 0.1 micro l), was infused into the dorsal PAG and behavioral responses of mice were evaluated in two d...
Article
Following intracerebroventricular (i.c.v.) injection of ovine CRF (oCRF), an endogenous peptide agonist at both CRF1 and CRF2 receptors, defensive behaviors of CD-1 mice were evaluated in the Mouse Defensive Test Battery (MDTB). Behavioral measures taken before, during, and after predator (a hand-held anesthetized rat) confrontation included explor...
Article
This study investigated the role of the hippocampus in both unconditioned and conditioned defensive behaviors by examining the effects of pretraining ibotenic acid lesions to the dorsal and ventral hippocampus in male Long-Evans hooded rats exposed to three types of threat stimuli: cat-odor, a live cat and footshock. Defensive behaviors were assess...
Article
In rodents, the administration of amphetamine has been associated with increased locomotor activity and stereotypy, and an emerging body of evidence suggests that it also enhances anxiety-like behavior in a number of animal models. Ethoexperimental analyses have outlined an array of defensive behaviors to threat that are responsive to anxiolytic, p...
Chapter
Aggression and defense are important behavioral strategies throughout the animal kingdom, and are linked to activation of brain areas in the prefrontal cortex, limbic system, hypothalamus, and periaqueductal gray matter. While substantial progress has been made toward understanding the neural and neurotransmitter systems underlying defense, and the...
Article
Conducted 3 experiments that examined the effect of fear on 2 types of aggression in rats by adding a cat stimulus to a colony in which the dominant male was attacking an intruder (offensive aggression) or to a tube test situation in which defensive biting was measured before and during tailshock. The cat completely abolished offense in the colony;...
Article
The primary goal of this book is to summarize and synthesize recent advances in the biological study of aggression. Other than maternal aggression, most aggressive encounters among human and non-human animals represent a male proclivity; thus, most of the research in this book describes and discusses studies using the most appropriate murine model:...
Article
Full-text available
Developmental defects of enamel-stress histomarker rings (accentuated striae) may be a potential measure of diminished vagal tone in research on extreme stress such as exposure to combat. To develop an animal model of this measure, we examined the enamel of rat incisors which erupt continuously. We examined incisors from 15 stressed-colony rats and...
Article
Defensive responses include an array of specific behaviors, including flight, freezing, risk assessment, and defensive threat/attack, that are elicited by unconditioned threat stimuli such as predators or predator odors. Some individual defensive behaviors are selectively responsive to drugs effective against generalized anxiety disorder or panic,...
Article
Aggression research is moribund. Lack of research over the past two decades has left many issues. (1) Understanding varieties of agonistic behaviour in an ethological context: categories differing in behaviours, target sites and function include offence, defensive attack, and predation. Biological systems must be determined for each of these. (2) I...
Article
In the present study, we introduce an experimental procedure to study, in rats, a wide range of natural defensive reactions. Animals were tested in an experimental apparatus that consisted of a home cage (25 x 25 x 25 cm) connected to another chamber (25 x 25 x 25 cm-the food compartment) by a hallway (12.5 cm wide and 100 cm long, with 25-cm high...
Article
Exposure of rats to a cat elicits Fos activity in a number of brain areas or structures. Based on hodological relationships of these, Canteras has proposed a medial hypothalamic defense system, with input from several forebrain sites. Both electrolytic and neurotoxic lesions of the dorsal premammillary nucleus, which shows the strongest Fos respons...