Promoting Good Nonhuman Primate Welfare outside Regular Working Hours.

Promoting good primate welfare outside of daylight hours is an important task. The responsibility to provide a complex environment and environmental enrichment is an essential element of primate wellbeing programs that should be approached from a 24-h perspective and planned according to the species and individual needs, including giving animals the ability to interact with and control their environment during hours when animal care staff are not present. One must be aware, however, that their needs may differ at night-time from their care needs during the day when staff are present. Assessing welfare and providing enrichment during times when staff are not on hand can be achieved through the use of a variety of technologies, such as night-view cameras, animal-centred technologies, and data loggers. This paper will address the relevant topics concerning the care and welfare of primates during off-hours, and the use of related technologies to facilitate and assess wellbeing at these times.

The principle of the 3Rs between aspiration and reality.

The Principle of the 3Rs is widely recognised as the methodological and ethical backbone of contemporary animal research. Different authors also stress the reciprocal links among the 3Rs, and how these often complement and reinforce each other. We very much agree with this point, but in this contribution we would like to raise some problems related to the application of the "3Rs". There is an obvious link among "Replacement, "Reduction" and "Refinement", but it is worth to notice also that each "R" has its own conceptual characteristics, as well as its own level of applicability. For example, a realistic "methodological inertia" has to be expected more in the case of "Replacement" than in the case of "Refinement". This also leads to a second order of issues, and here we will offer our experience as projects evaluators. The "3Rs" differ also in the possibility to verify how are applied by the proponents of research protocols involving the use of animal models. Sometimes it appears that the application of the Principle still resolves itself in the use of formulaic sentences, from which it is difficult to really understand the reality of the laboratory decisional and procedural processes. However, the demanding characteristics of the "3Rs" can vary greatly, and this is something that has to be considered. We propose that a network, or a virtual platform, of evaluators could help both researchers and evaluators for a more satisfactory understanding and pragmatic application of the Principle of the 3Rs.

Personality and lateralization in common marmosets (Callithrix jacchus).

Specialization of the left and right hemispheres to control behavioural responses may represent one of the mechanisms underlying individual differences in personality structure, as well as the preferential use of one hand. The present study investigated the relationship between personality and hand preference in common marmosets (Callithrix jacchus), a little New World monkey that presents highly consistent and stable individual hand preferences for simple reaching. To address this issue, data on 56 different behaviours from the species' behavioural repertoire were measured in 10 different laboratory tests and during observations under social conditions on 16 adult common marmosets. Stable behavioural variables were aggregated a priori into 13 personality traits. Exploratory Factor Analysis (EFA) on personality traits was carried out to verify the presence of major personality factors, and their relationship with direction and strength of individual hand preferences was assessed by multiple regression, taking into account sex and age of the subjects. The largest number of species-specific behaviours so far investigated in this species was taken into account and robust temporal stability between two testing periods was verified. We confirm that common marmosets are characterized by specific and stable personality profiles. A single personality factor, accounting for about 38% of the total variance, was found by EFA, that describes the interest towards unusual and new experiences and resembles the human Openness domain. The strength of the hand preference was found to be predicted by this personality factor, that we named Inquisitiveness. Present results highlight common marmoset as a useful primate model for the study of the relationship between personality and lateralization.

A Behavioural Case Study of Early Social Isolation of a Subadult White-Handed Gibbon (Hylobates lar).

Our aim in this study was to analyse the effects of early social isolation on the behaviour of a white-handed gibbon (Hylobates lar) and at the same time to improve his level of welfare. The subject was a 6-year-old male, isolated from conspecific as well as other non-human primates since he was 3 months old. We presented the gibbon with a series of species-specific vocalisations, and we then introduced a 23-year-old conspecific female into his cage. Our subject did not respond to playbacks, whereas he immediately interacted positively with the conspecific female. After 2 days of presentation, the pair started to spend time in proximity to each other and initiated grooming through the wire-mesh dividing the cages. Four days later we recorded vocal duets. No obvious ste-reotypic behaviours were observed, and the prolonged isolation did not seem to compromise the ability of the young gibbon to socialise with the female conspecific. It appears that prolonged isolation does not always compromise the possibility of recovering socially in a satisfactory manner.

Adult Empathy: Possible Gender Differences in Gene-Environment Architecture for Cognitive and Emotional Components in a Large Italian Twin Sample.

Empathy plays a central role in prosocial behavior and human cooperation. Very few twin researchers have investigated innate and environmental effects in adult empathy, and twin research on gender differences in these effects is sparse. The goal of this study was to examine innate and environmental influences on three components of an empathy scale frequently used with adults - the expression of cognitive (CE), emotional (EE), and social skills (SS) empathy - and to explore gender differences in the influences. Study participants were ~1,700 twins (18-65 years) enrolled in the Italian Twin Registry. Empathy was assessed with the Italian version of the Empathy Quotient (EQ), for which the three-factor structure (i.e., CE, EE, and SS) was confirmed. Twin correlations in monozygotic and dizygotic pairs, and males and females were estimated for the total EQ and subscale scores, and univariate genetic model fitting was carried out. Women's empathy (i.e., total EQ as well as CE and EE subdimensions) was predominantly driven by genetic factors and individual experiences, whereas for males, no genetic contribution or important shared and individual environmental effects emerged. Although of large magnitude, the gender differences did not reach statistical significance. Age did not moderate empathy heritability in adulthood. Only for the SS subscale were genetic and environmental proportions of variance similar for men and women. This study suggests possible gender-specific innate and environmental influences on empathy and its cognitive and emotional components that need to be confirmed in future studies.

Polymorphism of the 3'-UTR of the dopamine transporter gene (DAT) in New World monkeys.

Genetic polymorphism in the 3'-untranslated region (3'-UTR) of the dopamine transporter (DAT) gene has been reported in both human and nonhuman primates, and the variable number of tandem repeats (VNTR) polymorphism has been related to several neurological and psychiatric disorders. As New World primates have been employed as models in biomedical research in these fields, in the present study we assessed genetic variation in the DAT gene in 25 robust capuchin monkeys (Sapajus spp.) and 39 common marmosets (Callithrix jacchus). Using enzymatic amplification followed by sequencing of amplified fragments, a VNTR polymorphism in the 3'-UTR region of the DAT gene was identified in both robust capuchins and common marmosets. The polymorphic tandem repeat of 40-bp basic units is similar to the human VNTR consensus sequence, with size variants composed of 9, 10, and 11 units in marmosets and 8, 9, 13, and 17 basic units in capuchins. We found behavioral evidence that carrying the 10-repeat DAT allele promotes flexible choice and maximization of foraging in marmosets tested in an operant choice paradigm. Moreover, in an intertemporal choice task, capuchins with longer repeat variants show less self-controlled choices than capuchins with at least one short repeat variant. Future research should focus on the relationship between these DAT polymorphisms, dopamine reuptake via the dopamine transporter, and behavioral and cognitive variation across New World monkey individuals.

Exchanging grooming, but not tolerance and aggression in common marmosets (Callithrix jacchus).

In this study, we investigated the reciprocal exchanges of grooming, tolerance and reduced aggression in common marmosets (Callithrix jacchus), a cooperatively breeding primate whose groups are typically characterized by uniformly high genetic relatedness and high interdependency between group members. Both partner control and partner choice processes played a role in the reciprocal exchanges of grooming. In contrast, we did not find any evidence of reciprocity between grooming and tolerance over a preferred food source or between grooming and reduced aggression. Thus, reciprocity seems to play a variable role in the exchange of cooperative behaviors in marmosets.

EU guidelines for the care and welfare of an "exceptional invertebrate class" in scientific research. Commentary.

Cephalopods have been defined as "advanced invertebrates" due to the complexity of their nervous system and to their sophisticated behavioural repertoire. However, until recently, the protection and welfare of this class of invertebrates has been mostly disregarded by EU regulations on the use of laboratory animals. The inclusion of "live cephalopods" in the Directive 2010/63/EU has been prompted by new scientific knowledge on the "sentience" of animals used for experimental or other scientific purposes, a fundamental criterion to which animal species are included or not under the protective umbrella of the Directive. In this scenario, the imminent publication of the Guidelines for the care and welfare of cephalopods in research as an initiative by the CephRes-FELASA-Boyd Group is a sign of ethical progress in the consideration of animals in research, and is likely to have a significant impact on both scientific and practical aspects of research conducted with these animals.

Individual differences in gambling proneness among rats and common marmosets: an automated choice task.

Interest is rising for animal modeling of pathological gambling. Using the operant probabilistic-delivery task (PDT), gambling proneness can be evaluated in laboratory animals. Drawing a comparison with rats, this study evaluated the common marmoset (Callithrix jacchus) using a PDT. By nose- or hand-poking, subjects learnt to prefer a large (LLL, 5-6 pellets) over a small (SS, 1-2 pellets) reward and, subsequently, the probability of occurrence of large-reward delivery was decreased progressively to very low levels (from 100% to 17% and 14%). As probability decreased, subjects showed a great versus little shift in preference from LLL to SS reinforcer. Hence, two distinct subpopulations ("non-gambler" versus "gambler") were differentiated within each species. A proof of the model validity comes from marmosets' reaction to reward-delivery omission. Namely, depending on individual temperament ("gambler" versus "non-gambler"), they showed either persistence (i.e., inadequate pokes towards LLL) or restlessness (i.e., inadequate pokes towards SS), respectively. In conclusion, the marmoset could be a suitable model for preclinical gambling studies. Implementation of the PDT to species other than rats may be relevant for determining its external validity/generalizability and improving its face/construct validity.

Individual differences in choice (in)flexibility but not impulsivity in the common marmoset: an automated, operant-behavior choice task.

UNLABELLED: Individual differences in behavioural flexibility are a significant issue in human psychopathology as well as in its animal models. We aimed to investigate individual variations of operant-choice behaviour in the common marmoset (Callithrix jacchus), a small New World primate, using a new operant panel with two hand-poking holes. METHODS: Experimental subjects (N=16) were presented with a choice between a Small & Soon (SS) vs a Large & Late (LL) food reward. After extensive training (31 daily sessions with no delay, during which a basal, large-reward preference developed), the delay before release of LL was progressively increased (from 0 to 60 s, during 16 daily sessions; indifferent point at delay=9 s). Subjects were classified as either "flexible" or "non-flexible", respectively, based on a decrease (or not) in the preference for LL with increasing delays. Each subject was also classified as "maximizer" (or "non-maximizer") based on capacity (or not) to maximize the food payoff as delay increased. RESULTS: Upon delays shorter than the indifferent point (<9s), none of the subjects showed a shift from LL to SS, denoting a lack of delay-induced, cognitive impulsivity. Individual differences only emerged upon delays longer than the indifferent point (>9 s), when a preference shift could be interpreted as economically-driven. In general, a profile of few unrewarded hand-pokes in reaction to initial delays (i.e., a low motor impulsivity) and of clear-cut basal LL preference seemed to predict elevated flexibility of choices and better food payoff, which was typical of subjects classified as both "flexible & maximizer". CONCLUSION: These results provide normative data on the marmosets, which can be used as a model for the investigation of 1) individual differences in behavioural flexibility, as well as 2) biological mechanisms rooted in our evolutionary history.

Monomorphic region of the serotonin transporter promoter gene in New World monkeys.

Genetic variation in the human serotonin system has long been studied because of its functional consequences and links to various neuropsychiatric and behavior-related disorders. Among non-human primates, the common marmosets (Callithrix jacchus) and tufted capuchins monkeys (Cebus apella) are becoming increasingly used as models to study the effects of genes, environments, and their interaction on physiology and complex behavior. In order to investigate the independent functions of and potential interactions between serotonin-related genes, anxiety and neuropsychiatric disorders, we analyzed the presence and variability of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) in marmoset and capuchin monkeys. By PCR and using heterologous primers from the human sequence, we amplified and then sequenced the corresponding 5-HTT region in marmosets and capuchins. The resulting data revealed the presence of a tandem repeat sequence similar to that described in humans, but unlike humans and other Old World primates, no variable length alleles were detected in these New World monkeys, suggesting that if serotonin transporter is involved in modulating behavior in these animals it does so through different molecular mechanisms.