Biomedical subjects

Steven J Schapiro

Publications and source records attributed to Steven J Schapiro.

15 recordsLinked to original sources

PubMed2006

Positive reinforcement training affects hematologic and serum chemistry values in captive chimpanzees (Pan troglodytes).

Positive reinforcement training (PRT) techniques have received considerable attention for their stress reduction potential in the behavioral management of captive nonhuman primates. However, few published empirical studies have provided physiological data to support this position. To address this issue, PRT techniques were used to train chimpanzees (Pan troglodytes) to voluntarily present a leg for an intramuscular (IM) injection of anesthetic. Hematology and serum chemistry profiles were collected from healthy chimpanzees (n=128) of both sexes and various ages during their routine annual physical examinations over a 7-year period. Specific variables potentially indicative of acute stress (i.e., total white blood cell (WBC) counts, absolute segmented neutrophils (SEG), glucose (GLU) levels, and hematocrit (HCT) levels) were analyzed to determine whether the method used to administer the anesthetic (voluntary present for injection vs. involuntary injection) affected the physiological parameters. Subjects that voluntarily presented for an anesthetic injection had significantly lower mean total WBC counts, SEG, and GLU levels than subjects that were involuntarily anesthetized by more traditional means. Within-subjects analyses revealed the same pattern of results. This is one of the first data sets to objectively demonstrate that PRT for voluntary presentation of IM injections of anesthetic can significantly affect some of the physiological measures correlated with stress responses to chemical restraint in captive chimpanzees.

Anesthesia↗

PubMed2006

Parental and perinatal factors influencing the development of handedness in captive chimpanzees.

It has been proposed that human right handedness is determined by genetic factors associated with the emergence of language, whereas non-human primate handedness is determined by random, non-genetic factors. These different mechanisms account for differences in the distribution of handedness between human and non-human primates. Here we report evidence that genetic factors play a role in the determination of handedness in chimpanzees. We further report that differential rearing has no influence on the expression of handedness in related individuals. Contrary to many theories of the origin of handedness, these results indicate that genetic factors have a significant influence on handedness in chimpanzees.

Animals↗

PubMed2006

Preparing chimpanzees for laboratory research.

The chimpanzee is the only representative of the Great Apes that is extensively involved in biomedical research in primate laboratories. These apes are used as animal models in a variety of studies, including research on infectious disease, parasitic disease, pharmacokinetic studies, neuroscience, cognition, and behavior. Chimpanzees used in biomedical research in the United States reside largely in six specialized research and holding facilities, and most of the research with them is conducted at these sites. Given the relatively small population of chimpanzees and its importance to biomedical research, it is imperative that we carefully manage the care, production, and use of these animals in biomedical research studies. Selection criteria and preparation techniques are reviewed in this article in an effort to begin a discussion on best practices for choosing and handling chimpanzees participating in biomedical research. The use of routine health assessment information is described for subject selection, as are behavioral issues to be considered. Due to the relatively small number of chimpanzees available, issues related to experimental design and multiple uses of chimpanzees are discussed. Practices related to the transportation and acclimation of chimpanzees are described. Finally, behavioral conditioning procedures are discussed, including habituation, desensitization, and positive reinforcement training that have been applied to reduce animal distress and improve the quality of the science being conducted with chimpanzee subjects.

Acclimatization↗

PubMed2005

Chimpanzees are indifferent to the welfare of unrelated group members.

Humans are an unusually prosocial species-we vote, give blood, recycle, give tithes and punish violators of social norms. Experimental evidence indicates that people willingly incur costs to help strangers in anonymous one-shot interactions, and that altruistic behaviour is motivated, at least in part, by empathy and concern for the welfare of others (hereafter referred to as other-regarding preferences). In contrast, cooperative behaviour in non-human primates is mainly limited to kin and reciprocating partners, and is virtually never extended to unfamiliar individuals. Here we present experimental tests of the existence of other-regarding preferences in non-human primates, and show that chimpanzees (Pan troglodytes) do not take advantage of opportunities to deliver benefits to familiar individuals at no material cost to themselves, suggesting that chimpanzee behaviour is not motivated by other-regarding preferences. Chimpanzees are among the primates most likely to demonstrate prosocial behaviours. They participate in a variety of collective activities, including territorial patrols, coalitionary aggression, cooperative hunting, food sharing and joint mate guarding. Consolation of victims of aggression and anecdotal accounts of solicitous treatment of injured individuals suggest that chimpanzees may feel empathy. Chimpanzees sometimes reject exchanges in which they receive less valuable rewards than others, which may be one element of a 'sense of fairness', but there is no evidence that they are averse to interactions in which they benefit more than others.

Aging↗

PubMed2005

Chimpanzee (Pan troglodytes) intentional communication is not contingent upon food.

Studies of great apes have revealed that they use manual gestures and other signals to communicate about distal objects. There is also evidence that chimpanzees modify the types of communicative signals they use depending on the attentional state of a human communicative partner. The majority of previous studies have involved chimpanzees requesting food items from a human experimenter. Here, these same communicative behaviors are reported in chimpanzees requesting a tool from a human observer. In this study, captive chimpanzees were found to gesture, vocalize, and display more often when the experimenter had a tool than when she did not. It was also found that chimpanzees responded differentially based on the attentional state of a human experimenter, and when given the wrong tool persisted in their communicative efforts. Implications for the referential and intentional nature of chimpanzee communicative signaling are discussed.

Animal Communication↗

PubMed2005

Maternal age, parity, and reproductive outcome in captive chimpanzees (Pan troglodytes).

As early as the 1970s, it was suggested that nonhuman primates may serve as models of human reproductive senescence. In the present study, the reproductive outcomes of 1,255 pregnancies in captive chimpanzees (Pan troglodytes) were examined in relation to parity and its covariate, maternal age. The results show that the percentage of positive pregnancy outcomes was negatively correlated with increasing parity. In addition, spontaneous abortions, stillbirths, and caesarian sections (C-sections) were positively correlated with increasing parity. Maternal age, rather than parity, was found to be the most important predictor of negative birth outcome. This study supports research demonstrating reproductive decline and termination in nonhuman primates, and is the first to quantitatively account for this phenomenon in captive female chimpanzees.

Abortion, Veterinary↗

PubMed2005

Factors influencing the prevalence and handedness for throwing in captive chimpanzees (Pan troglodytes).

Humans throw right-handed, and it has been suggested that the neurophysiological demands of aimed throwing may have served as a precursor to the evolution of left hemisphere specialization for linguistic functions. Although there are descriptions of throwing by wild and captive chimpanzees (Pan troglodytes), systematic observations of aimed throwing and handedness have not been reported. In this article, evidence of population-level right-handedness for throwing is reported in 2 samples of captive chimpanzees. It is further reported that right-handed throwing is more pronounced than other measures of handedness in captive chimpanzees. The implications of these findings are discussed in the context of theories relating throwing to the evolution of lateralization for language functions.

Animals↗

PubMed2005

Training nonhuman primates to perform behaviors useful in biomedical research.

Data collected from NHPs that are trained to participate voluntarily in husbandry, veterinary, and research procedures are likely to have particular value. The authors present the results of a series of studies that examined the effects of PRT on the performance by chimpanzees of a variety of biomedically relevant behaviors: presenting their perineum for pinworm testing, providing a semen sample, presenting for an s.c. injection, and presenting for an i.m. injection. The overall trends across studies indicate that PRT techniques have significant value in the handling and management of NHPs in many laboratory research settings, including less variability in the data collected and fewer potential confounding variables, which should lead to important refinements in the definition of NHPs as biomedical research models.

Animals↗

PubMed2005

The distribution and development of handedness for manual gestures in captive chimpanzees (Pan troglodytes).

This article describes the distribution and development of handedness for manual gestures in captive chimpanzees. Data on handedness for unimanual gestures were collected in a sample of 227 captive chimpanzees. Handedness for these gestures was compared with handedness for three other measures of hand use: tool use, reaching, and coordinated bimanual actions. Chimpanzees were significantly more right-handed for gestures than for all other measures of hand use. Hand use for simple reaching at 3 to 4 years of age predicted hand use for gestures 10 years later. Use of the right hand for gestures was significantly higher when gestures were accompanied by a vocalization than when they were not. The collective results suggest that left-hemisphere specialization for language may have evolved initially from asymmetries in manual gestures in the common ancestor of chimpanzees and humans, rather than from hand use associated with other, non-communicative motor actions, including tool use and coordinated bimanual actions, as has been previously suggested in the literature.

Age Factors↗

PubMed2004

Use of primates in research: a global overview.

We assessed the use of nonhuman primates and nonhuman primate biological material in research by reviewing studies published in 2001 in peer-reviewed journals. The number and species of primates used, the origin of the animals, the type of study, the area of research of the investigation, and the location at which the research was performed were tabulated. Additionally, factors related to the animals that may have affected the outcome of the experiments were recorded. A total of 2,937 articles involving 4,411 studies that employed nonhuman primates or nonhuman primate biological material were identified and analyzed. More than 41,000 animals were represented in the studies published in 2001. In the 14% of studies for which re-use could be determined, 69% involved animals that had been used in previous experiments. Published studies most commonly used nonhuman primates or nonhuman primate biological material from the species Chlorocebus aethiops (19%), Macaca mulatta (18%), M. fascicularis (9%), and Papio spp. (6%). Of these studies, 54% were classified as in vitro studies, 14% as noninvasive, 30% as chronic, and 1% were considered acute. Nonhuman primates were primarily used in research areas in which they appear to be the most appropriate models for humans. The most common areas of research were microbiology (including HIV/AIDS (26%)), neuroscience (19%), and biochemistry/chemistry (12%). Most (84%) of the primate research published in 2001 was conducted in North America, Europe, and Japan. The animals and conditions under which they were housed and used were rarely described. Although it is estimated that nonhuman primates account for an extremely small fraction of all animals used in research, their special status makes it important to report the many husbandry and environmental factors that influence the research results generated. This analysis has identified that editors rarely require authors to provide comprehensive information concerning the subjects (e.g., their origin), treatment conditions, and experimental procedures utilized in the studies they publish. The present analysis addresses the use of primates for research, including the effects of a shortage of suitable nonhuman primate subjects in many research areas.

Animal Experimentation↗

PubMed2004

Chimpanzees (Pan troglodytes) are predominantly right-handed: replication in three populations of apes.

Population-level right-handedness has historically been considered a hallmark of human evolution. Even though recent studies in chimpanzees (Pan troglodytes) have demonstrated population-level right-handedness for certain behaviors, some have questioned the validity and consistency of these findings by arguing that reported laterality effects are specific to certain colonies of apes and to those chimpanzees reared by humans. The authors report evidence of population-level right-handedness in 3 separate colonies of chimpanzees. Moreover, handedness in the 3 colonies was unrelated to the proportion of subjects that were raised by humans. This is the strongest evidence to date that population-level handedness is evident in chimpanzees and is not an artifact of human rearing.

Animals↗

PubMed2004

SHIV transmission and susceptibility to re-exposure through social contact following vaccination with an HIV synthetic peptide-cocktail: a case study.

An effective vaccine against human immunodeficiency virus (HIV) should not only protect from infection and development of acquired immunodeficiency syndrome (AIDS), but also prevent potential transmission to naïve partners. We recently reported protection of rhesus macaques from chronic simian-human immunodeficiency virus (SHIV) infection and AIDS by an HIV envelope peptide-cocktail vaccine. In the present case study, we observed that one of the vaccinated females, with undetectable circulating virus, when housed in a pair with a naïve male, did not transmit the infection over a 35-week period of social contact. Subsequent experimental challenge of the male with the same SHIV strain resulted in high-level infection and transmission to its female cage-mate. However, the virus was undetectable in the female by 12 weeks without further vaccination, validating the multivalent peptide cocktail vaccine approach in the SHIV-rhesus model, and suggesting its potential utility as an HIV vaccine strategy for humans.

AIDS Vaccines↗

PubMed2003

The use of positive reinforcement training techniques to enhance the care, management, and welfare of primates in the laboratory.

Handled frequently and subjected to a wide range of medical procedures that may be particularly invasive, nonhuman animals in a laboratory setting have unique needs. To produce the most reliable research results and to protect and enhance the well-being of the animals, it is desirable to perform these procedures with as little stress for the animals as possible. Positive reinforcement training can use targeted activities and procedures to achieve the voluntary cooperation of nonhuman primates. The benefits of such work include diminished stress on the animals, enhanced flexibility and reliability in data collection, and a reduction in the use of anesthesia. Training also provides the means to mitigate social problems, aid in introductions, reduce abnormal behavior, enhance enrichment programs, and increase the safety of attending personnel. This article describes the application of operant conditioning techniques to animal management.

Animal Husbandry↗

PubMed2003

Positive reinforcement training as a technique to alter nonhuman primate behavior: quantitative assessments of effectiveness.

Many suggest that operant conditioning techniques can be applied successfully to improve the behavioral management of nonhuman primates in research settings. However, relatively little empirical data exist to support this claim. This article is a review of several studies that discussed applied positive reinforcement training techniques (PRT) on breeding/research colonies of rhesus macaques (Macaca mulatta) and chimpanzees (Pan troglodytes) at The University of Texas M. D. Anderson Cancer Center and measured their effectiveness. Empirical analyses quantified the amount of time required to train rhesus monkeys to come up, station, target, and stay. Additionally, a study found that time spent affiliating by female rhesus was changed as a function of training low affiliators to affiliate more and high affiliators to affiliate less. Another study successfully trained chimpanzees to feed without fighting and to come inside on command. PRT is an important behavioral management tool that can improve the care and welfare of primates in captivity. Published empirical findings are essential for managers to assess objectively the utility of positive reinforcement training techniques in enhancing captive management and research procedures.

Animal Husbandry↗

PubMed2002

Effects of social manipulations and environmental enrichment on behavior and cell-mediated immune responses in rhesus macaques.

This paper reviews a series of studies that have examined the effects of manipulations to the social and the inanimate environments on the behavior and cell-mediated immune responses of rhesus macaques of various ages living in different settings. In general, enrichment of the inanimate environment with toys, structures, foraging devices, and/or videotapes increased the amount of species-typical behavior expressed by the monkeys, but did not affect their immune responses. Housing monkeys socially, on the other hand, not only resulted in increased time spent in species-typical activities, but also resulted in (1) decreases in time spent in abnormal behavior and (2) changes in a number of immune parameters. Additionally, attempts to directly influence the affiliative interactions of socially housed adult rhesus have resulted in systematic changes in affiliative behavior, although anticipated accompanying systematic alterations to cell-mediated immune responses have yet to be realized. The data suggest that aspects of the physical and social environments influence behavioral and immunological parameters in captive macaques in the absence of other experimental manipulations. As such, these influences need to be appropriately managed and/or controlled in order to minimize potential confounds in experimental designs.

Animals↗