Myeloablative irradiation in non-human primates

Purpose  We used total body irradiation (TBI) as conditioning for cord blood transplantation studies in pigtailed macaques. In these studies, different doses of TBI were explored to obtain optimal myelosuppression with acceptable radiation-related side effects.
Methods  Four macaques received TBI ranging from 800 to 1320 cGy, followed by standard post-transplant care. Hematopoietic recovery was monitored by CBC and donor contribution by variable number of tandem repeats analysis.
Results  Animals receiving 800 or 1020 cGy TBI tolerated the irradiation well with autologous recovery of neutrophils within 24 days. At a dose of 1200 cGy, neither autologous recovery nor extramedullary toxicity was observed. A fourth animal received 1320 cGy of TBI and suffered significant toxicity necessitating termination of the study.
Conclusions  We conclude that previously considered myeloablative doses of TBI allowed for autologous recovery in the pigtailed macaque, and that a dose of 1200 cGy may be most appropriate, providing both myeloablation and acceptable non-hematopoietic toxicities.     

Hepatitis viruses in non-human primates

BACKGROUND: Previous epidemiological studies of rural human populations in Gabon reveal a high prevalence of human hepatitis A, B, C and D viruses. In order to investigate the prevalence of the blood-born hepatitis viruses in apes and monkeys living in the same area, we performed an epidemiological survey of HBV, HCV and HDV in wild-born non-human primates. METHODS: We tested 441 wild-born non-human primates from Gabon and Congo and 132 imported monkeys for the presence of serological markers of HBV, HCV and HDV infections. RESULTS: None of Cercopithecidae monkeys were reactive against HBV/HDV and HCV. In contrast, 29.2% of wild-born great apes (154 chimpanzees and 14 gorillas) were positive for HBV serological markers. Nine chimpanzees were in the replicative phase of HBV infection. None of these HBV infected chimpanzees exhibited symptoms or significant changes in serum clinical chemistry related to HBV infection. CONCLUSIONS: The negativity to HCV-related viruses and the negativity of the Cercopithecidae species tested against HBV/HDV do not allow us to definitively rule out the presence of an animal counterpart of human hepatitis viruses in non-human primates.     

Interspecific audience effects on the alarm-calling behaviour of a kleptoparasitic bird

Audience effects are increasingly recognized as an important aspect of intraspecific communication. Yet despite the common occurrence of interspecific interactions and considerable evidence that individuals respond to the calls of heterospecifics, empirical evidence for interspecific audience effects on signalling behaviour is lacking. Here we present evidence of an interspecific audience effect on the alarm-calling behaviour of the kleptoparasitic fork-tailed drongo (Dicrurus adsimilis). When foraging solitarily, drongos regularly alarm at aerial predators, but rarely alarm at terrestrial predators. In contrast, when drongos are following terrestrially foraging pied babblers (Turdoides bicolor) for kleptoparasitic opportunities, they consistently give alarm calls to both aerial and terrestrial predators. This change occurs despite no difference in the amount of time that drongos spend foraging terrestrially. Babblers respond to drongo alarm calls by fleeing to cover, providing drongos with opportunities to steal babbler food items by occasionally giving false alarm calls. This provides an example of an interspecific audience effect on alarm-calling behaviour that may be explained by the benefits received from audience response.     

Use of florfenicol in non-human primates

Studies were undertaken to determine if florfenicol, an antimicrobial agent structurally similar to chloramphenicol, could be used as an effective broad spectrum antibiotic for the treatment of bacterial infections in primates. Florfenicol was developed as an injectable antibiotic for use in cattle on an every other day dosing schedule. Its broad spectrum activity, long duration of action following i.m. administration, and its safety as compared with chloramphenicol made it an attractive antibiotic for use in non-human primates. Previous studies had shown that florfenicol is effective against common primate pathogens such as Salmonella, Klebsiella, Escherichia coli, Bordetella bronchiseptica, Streptococcus pneumoniae, Staphylococcus spp., and Yersinia pseudotuberculosis. We performed experiments on a total of 15 macaques. The animals were given florfenicol at 50 mg/kg i.m. and blood samples taken at various time points. Serum was evaluated for florfenicol absorption. Necropsies were also performed to determine if major organs were affected and to determine the effects of i.m. injection of florfenicol. We determined that florfenicol given every 48 hours in rhesus macaques results in blood levels that were acceptable for therapeutic use. The effect on muscle tissue of i.m. injection was similar to ketamine and normal saline. There were no gross lesions observed and no changes with tissues submitted for histology. Our work shows that with further studies, florfenicol may be useful when injectable antibiotic therapy is required in non-human primates.     

Social bonds affect anti-predator behaviour in a tolerant species of macaque, Macaca nigra

Enduring positive social bonds between individuals are crucial for humans' health and well being. Similar bonds can be found in a wide range of taxa, revealing the evolutionary origins of humans' social bonds. Evidence suggests that these strong social bonds can function to buffer the negative effects of living in groups, but it is not known whether they also function to minimize predation risk. Here, we show that crested macaques (Macaca nigra) react more strongly to playbacks of recruitment alarm calls (i.e. calls signalling the presence of a predator and eliciting cooperative mobbing behaviour) if they were produced by an individual with whom they share a strong social bond. Dominance relationships between caller and listener had no effect on the reaction of the listener. Thus, strong social bonds may improve the coordination and efficiency of cooperative defence against predators, and therefore increase chances of survival. This result broadens our understanding of the evolution and function of social bonds by highlighting their importance in the anti-predator context.     

Attention to elders' voice in non-human primates

The observed respect and attention to elders'' speech in traditional cultures appears to have a ‘universal’ component which questions its possible biological bases. Animals present differential attention to the vocalizations of other individuals according to their characteristics but little is known about the potential propensity to pay more attention to vocalizations of elders. On the basis of several hundreds of vocal exchanges recorded, here we show that aged female Campbell''s monkeys (Cercopithecus campbelli), despite being significantly less ‘loquacious’ than their younger adult counterparts, elicit many more responses when calling. These findings show that attention to elders'' vocal production appears in non-human primates, leading to new lines of questioning on human culture and language evolution.     

Grooming-at-a-distance by exchanging calls in non-human primates

The ‘social bonding hypothesis'' predicts that, in large social groups, functions of gestural grooming should be partially transferred to vocal interactions. Hence, vocal exchanges would have evolved in primates to play the role of grooming-at-a-distance in order to facilitate the maintenance of social cohesion. However, there are few empirical studies testing this hypothesis. To address this point, we compared the rate of contact call exchanges between females in two captive groups of Japanese macaques as a function of female age, dominance rank, genetic relatedness and social affinity measured by spatial proximity and grooming interactions. We found a significant positive relationship between the time spent on grooming by two females and the frequency with which they exchanged calls. Our results conform to the predictions of the social bonding hypothesis, i.e. vocal exchanges can be interpreted as grooming-at-a-distance.     

Chromobacterium violaceum infections in 13 non-human primates

Background Recently, an Indian‐origin macaque was found dead and Chromobacterium violaceum was isolated from the skin wound, and hepatic and pulmonary abscesses. Methods By searching the database, a total of thirteen cases of C. violaceum infection in pigtail macaques (n = 8), rhesus macaques (n = 4), and one baboon were identified from 2001 to 2010 at Tulane National Primate Research Center. Medical records were reviewed for breed, sex, age, clinical findings, treatment, outcome, bacteriology, and gross and histological findings. Results Seven pigtail macaques and one Indian‐origin rhesus macaque died of chromobacterial septicemia. All chromobacterial septicemic pigtail macaques were adult with higher incidence in female. Hepatic abscess and thrombosis were typical findings along with pulmonary abscess and thrombosis, renal venous thromboembolism, and necrosuppurative pleuritis, peritonitis, splenitis, myocarditis, pericarditis, and meningoencephalitis. Skin wound, uterine infection, and oral and respiratory exposure were considered the points of entry for these animals. Conclusions This represents the first report of chromobacteriosis in pigtail, rhesus macaque, and baboon. Our experience suggests that chromobacterial infections may be more common in non‐human primates than previously recognized.     

Predator regime influences innate anti-predator behaviour in the freshwater gastropod Lymnaea stagnalis

1. Predation incurs high fitness costs in aquatic organisms either through direct consumption or through avoidance responses that reduce time for activities such as feeding and reproduction. Hence, avoidance responses of aquatic organisms should vary to match closely the predation threat in their environment.
2. The freshwater gastropod Lymnaea stagnalis occurs in a variety of environments which vary in the presence or absence of predatory fish. We used naïve snails reared from six populations of this species experiencing different predator regimes (three co-occurring with molluscivorous fish and three without) to assess whether populations differed in the type and degree of their avoidance behaviours. Innate behavioural responses to four treatments (control, conspecific alarm cues, fish kairomones and fish kairomones paired with alarm cue) were compared in laboratory trials.
3. The primary anti-predator behaviour of L. stagnalis in response to fish kairomones was to crawl out of the water rather than seek refuge under water. This response was strongest when fish kairomones were paired with alarm cues, and varied depending on population origin; snails reared from populations co-occurring with predatory fish showed a stronger response than those raised from populations not experiencing such predators. In addition, populations co-occurring with predatory fish responded to the fish kairomones presented alone.
4. Our findings suggest that the degree of innate anti-predator behaviour shown by L. stagnalis , in terms of both the level of risk to which it responds and the degree of response, varies depending on the predator regime experienced by field populations. Together with previous work on cue association, this demonstrates that this gastropod is able to match its avoidance behaviour very closely to short and long term predation threats within its habitat.     

Social processes and mental abilities in non-human primates

International Journal of Primatology -     

Characterization of interleukin-8 receptors in non-human primates

Interleukin-8 is a chemokine with a potent neutrophil chemoatractant activity. In humans, two different cDNAs encoding human IL8 receptors designated IL8RA and IL8RB have been cloned. IL8RA binds IL8, while IL8RB binds IL8 as well as other α-chemokines. Both human IL8Rs are encoded by two genes physically linked on chromosome 2. TheIL8RA andIL8RB genes have open reading frames (ORF) lacking introns. By direct sequencing of the polymerase chain reaction products, we sequenced theIL8R genes of cell lines from four non-human primates: chimpanzee, gorilla, orangutan, and macaca. TheIL8RB encodes an ORF in the four non-human primates, showing 95%–99% similarity to the human IL8RB sequence. TheIL8RA homologue in gorilla and chimpanzee consisted of two ORF 98%–99% identical to the human sequence. The macaca and orangutanIL8RA homologues are pseudogenes: a 2 base pair insertion generated a sequence with several stop codons. In addition, we describe the physical linkage of these genes in the four non-human primates and discuss the evolutionary implications of these findings. The nucleotide sequence data reported in this paper have been submitted to the EMBL/GenBank nucleotide sequence databases and have assigned the accession numbers X91109 (PTIL8RA), X91110 (GGIL8RA), X91111 (PPIL8Ra), X91112 (MMIL8RA), X91113 (PTIL8RB), X9114 (GGIL8RB), X91115 (PPIL8RB), and X91116 (MMIL8RB)     

Visual categorization: accessing abstraction in non-human primates

Evolution might have set the basic foundations for abstract mental representation long ago. Because of language, mental abilities would have reached different degrees of sophistication in mammals and in humans but would be, essentially, of the same nature. Thus, humans and animals might rely on the same basic mechanisms that could be masked in humans by the use of sophisticated strategies. In this paper, monkey and human abilities are compared in a variety of perceptual tasks including visual categorization to assess behavioural similarities and dissimilarities, and to determine the level of abstraction of monkeys' mental representations. The question of how these abstract representations might be encoded in the brain is then addressed. A comparative study of the neural processing underlying abstract cognitive operations in animals and humans might help to understand when abstraction emerged in the phylogenetic scale, and how it increased in complexity.     

Training of laboratory-housed non-human primates in the UK

Abstract

Laboratory-housed non-human primates may experience a range of potential stressors, including physical and chemical restraint, venepuncture, injection, catching and cage-change. Training them to co-operate, using positive reinforcement techniques, is one means of significantly reducing the adverse impact of such procedures upon them and, therefore, is a refinement. Furthermore, the additional time that staff spend with the primates, and the need for individual recognition and close observation of animal behavior, mean that the trainer develops a relationship with each individual animal which can be beneficial for animal welfare (e.g., by reducing the occurrence of abnormal behavior and fear of humans). We surveyed use of training in thirteen UK establishments using and breeding primates, utilizing a mixed-mode questionnaire. The survey demonstrated that there is widespread awareness of training as a refinement and appreciation of its diverse benefits, but training is not used as widely or as fully as it might be. This is largely due to real constraints (principally staff and time and a lack of confidence in ability to train), and perceived constraints (such as a supposed lack of information on how to train and assessment of the benefits, and an overestimation of the time investment needed). There is also considerable variation between establishments in the purposes of training and techniques used, with a reliance on negative reinforcement in three. We conclude that there is considerable scope for refinement of common scientific, veterinary and husbandry procedures, and refer to some resources designed to help establishments take action (e.g., Prescott and Buchanan-Smith 2003).     

Pramipexole protects against MPTP toxicity in non-human primates

The neurotoxin MPTP induces nigral dopaminergic cell death in primates and produces a partial model of Parkinson's disease (PD). Pramipexole is a D2/D3 dopamine receptor agonist used in the symptomatic treatment of PD, and which also protects neuronal cells against dopaminergic toxins in vitro. We now demonstrate that pramipexole partially prevents MPTP toxicity in vivo in a primate species. Common marmosets were repeatedly treated with pramipexole either before, coincidentally with, or after low-dose MPTP treatment designed to induce a partial lesion of the substantia nigra. Animals pretreated with pramipexole had a significantly greater number of surviving tyrosine hydroxylase (TH) positive neurones in the pars compacta of the substantia nigra. Pramipexole pretreatment also prevented degeneration of striatal dopamine terminals. Treatment with pramipexole concurrently with MPTP or following MPTP did not prevent TH-positive cell loss. Pramipexole pretreatment appears to induce adaptive changes that protect against dopaminergic cell loss in primates.     

非人灵长类位置行为的辐射适应与研究进展

野生动物在长期进化中形成特定的行为模式以适应特定的生存环境。灵长类的位置行为研究对于理解灵长类进化、适应性的多样化以及生态学和解剖学十分关键。该文对已有文献进行了综述,针对位置行为的分类、季节性、以及具体地点和年龄性别差异性进行了总结,分析了灵长类位置行为的发展、特征以及研究现状,以期对今后非人灵长类位置行为的研究提供借鉴和参考,从而促进我国灵长类行为生态学理论体系的发展。