Publications by authors named "Sergio M Pellis"

57 Publications

Prefrontal neuronal morphology in kindling-prone (FAST) and kindling-resistant (SLOW) rats.

Synapse 2021 Sep 6;75(9):e22217. Epub 2021 Jul 6.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

The epileptogenic-prone (FAST) and epileptogenic-resistant (SLOW) rat strains have become a valuable tool for investigating neural plasticity. The strains were generated by breeding the rats that required the fewest amygdala stimulations to elicit a stage-5 convulsive seizure (FAST) and rats requiring the most stimulations (SLOW). Previous studies have shown differences in behavior and amygdala physiology in the two strains. This study examined the dendritic morphology of pyramidal neurons in the brains of adult male and female rats of the two strains. The brains were stained with the Golgi-Cox method and the length and branching from layer III pyramidal cells were measured in parietal cortex (Zilles Par1), medial frontal cortex (Zilles Cg3), and orbitofrontal cortex (Zilles AID) in these two strains of rats. We observed significantly longer dendrites in Cg3 in the FAST group but longer dendrites in the SLOW group in AID and Par1. There was also a sex difference (M > F) in Par1 in both strains. These morphological differences can provide insights into the neurobiological basis of the behavioral differences and suggest that localized changes in the amygdala do not occur independently of changes in other brain regions, and especially prefrontal cortex.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/syn.22217DOI Listing
September 2021

Does play shape hand use skill in rats?

Exp Brain Res 2021 Jun 18;239(6):1895-1909. Epub 2021 Apr 18.

Department of Neuroscience, Canadian Centre for Behavioural Research, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.

Hand use is a widespread act in many vertebrate lineages and subserves behaviors including locomotion, predation, feeding, nest construction, and grooming. In order to determine whether hand use is similarly used in social behavior, the present paper describes hand use in the social play of rats. In the course of rough and tumble play sessions, rats are found to make as many as twenty different movements a minute with each hand for the purposes of manipulating a partner into a subordinate position or defending against a partner's attack. The hand movements comprise signaling movements of touching, offensive manipulating of a partner to control a play engagement, and defensive hand movements directed toward blocking, pushing and pulling to parry an attack. For signaling, attack and defense, hand movements have a structure that is similar to the structure of hand movements used for other purposes including eating, but in their contact points on an opponent, they are tailored for partner control. Given the time devoted to play by rats, play likely features the social rat behavior with the most extensive use of hand movements. This extensive use of hand movements for social play is discussed in relation to the ubiquity of hand use in adaptive behavior, the evolution of hand use in the play of mammals, and in relation to extending the multifunctional theory of the purposes of play to include the education of skilled hand movements for various adult functions including as feeding.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00221-021-06097-6DOI Listing
June 2021

A naturalistic method to test depression: Anticipation of play.

Behav Brain Res 2021 02 24;398:112975. Epub 2020 Oct 24.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

The Wistar-Kyoto (WKY) rat was developed as a control for the spontaneous hypertensive rat but has subsequently also been used as a genetic animal model of depression due to its hyper-responsiveness to stress. We used anticipation of social reward (i.e., a play partner) to assess behavioural and vocal differences between the WKY and normal Wistar (WI) rats in the juvenile period. We found marked differences between groups; the WKY rats, were less active, vocalized less, and used significantly fewer types of 50-kHz calls in comparison to their WI counterparts. The animals were re-tested in adulthood and the same differences existed in overall activity, types of vocalizations and the behavioural vocal profiles used by the two groups of animals. These findings provide a robust baseline for an animal model of depression using a social paradigm. This paradigm may be useful to evaluate the efficacy of pharmaceutical interventions as potential treatments of depression in WKY rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbr.2020.112975DOI Listing
February 2021

Inferring functional patterns of tool use behavior from the temporal structure of object play sequences in a non-human primate species.

Physiol Behav 2020 08 15;222:112938. Epub 2020 May 15.

Department of Psychology, University of Lethbridge, Lethbridge, AB, Canada.

Inferring functional components of behavioral sequences is a crucial but challenging task. A systematic comparison of their temporal structure is a good starting point, based on the postulate that more functional traits are less structurally variable. We studied stone handling behavior (SH) in Balinese long-tailed macaques, a versatile form of stone-directed play. We tested the hypothesis that stones are used by male monkeys to stimulate their genitals in a sexual context (i.e., "sex toy" hypothesis). Specifically, two SH actions (i.e., "tap-on-groin" (TOG) and "rub-on-groin" (ROG), respectively the repetitive tapping and rubbing of a stone onto the genital area) gained functional properties as self-directed tool-assisted masturbation. Owing to the structural organization of playful activities, we predicted that SH sequences without TOG/ROG would exhibit higher levels of variability, repeatability and exaggeration than SH sequences with TOG/ROG. We also predicted that TOG/ROG would occur more often and last longer in SH sequences in which penile erection - a sexually-motivated physiological response in primates - was observed than in SH sequences in which penile erection was not observed. To identify and compare recurring series of SH patterns otherwise undetectable by using conventional quantitative approaches across SH sequences containing TOG/ROG or not, we used a temporal analysis known as "T-pattern detection and analysis" (TPA). Our predictions about variability, exaggeration and temporal association between TOG/ROG in males and penile erection were supported. As expected, SH sequences without TOG/ROG were, on average, more repeatable than SH sequences with TOG/ROG, but the difference was not statistically significant. Overall, the "sex toy" hypothesis was partly supported, and our results suggested that TOG and ROG are two forms of tool-assisted genital stimulation, possibly derived from the playful handling of stones. These findings are consistent with the view that tool use may evolve in stages from initially non-functional object manipulation, such as object play.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.physbeh.2020.112938DOI Listing
August 2020

Social and olfactory experiences modify neuronal morphology of orbital frontal cortex.

Behav Neurosci 2020 Feb;134(1):59-68

Department of Neuroscience, University of Lethbridge.

Structural modifications in the dendritic morphology of neurons occur following many forms of experience, including exposure to drugs, complex housing, and training in specific behavioral tasks. The present study examined morphological changes in orbitofrontal (OFC) and medial prefrontal cortex (mPFC) neurons of female rats following experience with a variety of social partners or nonsocial olfactory stimuli. We reasoned that experience with various social partners or olfactory stimuli, and the associated behavioral adaptations, would drive structural modifications in prefrontal cortex neurons engaged by these stimuli. Social experience was manipulated by providing rats with a novel cage-mate or housing the animal with the same cage-mate throughout the study. Similarly, olfactory experience was manipulated by introducing novel, nonsocial odors in the home cage or exposing the animals to the same home-cage odor throughout the study. Both forms of experience resulted in altered dendritic morphology in OFC neurons, whereas morphological changes in mPFC were comparatively small and limited to changes in spine density. These observations indicate that OFC and mPFC neurons respond differently to social and nonsocial olfactory stimulation in adulthood and join the growing body of data illustrating differential effects of experience on structural plasticity in OFC and mPFC. (PsycINFO Database Record (c) 2020 APA, all rights reserved).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/bne0000350DOI Listing
February 2020

Development of ultrasonic calls in rat pups follows similar patterns regardless of isolation distress.

Dev Psychobiol 2020 07 3;62(5):617-630. Epub 2019 Nov 3.

Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.

Ultrasonic vocalizations (USVs) emitted by rat pups have been extensively studied in the context of isolation from their mother and littermates. The heightened call rate of isolation-induced USVs indicates increased anxiety, whereas other acoustic parameters, such as frequency and call duration, are thought to be useful in reflecting developmental changes, which by weaning have developed into their adult form. However, it is possible that stress can affect the quality as well as the quantity of calls, and that as the pups become more mobile, the effects of the stress may change. Therefore, in the present study rats were tested in a test arena either in isolation or with littermates, so as to assess the effects of isolation stress on the developmental changes reported in the literature. Rat pups of both sexes were tested on multiple days from postnatal day (PND) 7 to weaning. Overall, the main changes in the frequency, duration, and types of calls were accounted for by age. The effects of isolation were minor, as were sex differences. This study indicates that the development of USVs in infant rats is a robust process and seemingly resistant to the effects of isolation-induced stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/dev.21933DOI Listing
July 2020

Is play a behavior system, and, if so, what kind?

Behav Processes 2019 Mar 14;160:1-9. Epub 2019 Jan 14.

Department of Psychology, University of Lethbridge, Lethbridge, Alberta, Canada.

Given that many behavior patterns cluster together in sequences that are organized to solve specific problems (e.g., foraging), a fruitful perspective within which to study behaviors is as distinct 'behavior systems'. Unlike many behavior systems that are widespread (e.g., anti-predator behavior, foraging, reproduction), behavior that can be relegated as playful is diverse, involving behavior patterns that are typically present in other behavior systems, sporadic in its phylogenetic distribution and relatively rare, suggesting that play is not a distinct behavior system. Yet the most striking and complex forms of play have the organizational integrity that suggests that it is a behavior system. One model that we develop in this paper, involves three stages of evolutionary transition to account for how the former can evolve into the latter. First, play-like behavior emerges from the incomplete development of other, functional behavior systems in some lineages. Second, in some of those lineages, the behavior patterns typical of particular behavior systems (e.g., foraging) are reorganized, leading to the evolution of specific 'play behavior systems'. Third, some lineages that have independently evolved more than one such play behavior system, coalesce these into a 'super system', allowing some animals to combine behavior patterns from different behavior systems during play. Alternative models are considered, but irrespective of the model, the overall message from this paper is that the conceptual framework of the behavior system approach can provide some new insights into the organization and diversity of play present in the animal kingdom.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2018.12.011DOI Listing
March 2019

Toward a Theory of the Evolution of Fair Play.

Front Psychol 2018 24;9:1167. Epub 2018 Jul 24.

Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.

Juvenile animals of many species engage in social play, but its functional significance is not well understood. This is especially true for a type of social play called fair play (Fp). Social play often involves behavioral patterns similar to adult behaviors (e.g., fighting, mating, and predatory activities), but young animals often engage in Fp behaviors such as role-reversals and self-handicapping, which raises the evolutionary problem of why Fp exists. A long-held working hypothesis, tracing back to the 19th century, is that social play provides contexts in which adult social skills needed for adulthood can be learned or, at least, refined. On this hypothesis, Fp may have evolved for adults to acquire skills for behaving fairly in the sense of equitable distribution of resources or treatment of others. We investigated the evolution of Fp using an evolutionary agent-based model of populations of social agents that learn adult fair behavior (Fb) by engaging in Fp as juveniles. In our model, adults produce offspring by accumulating resources over time through foraging. Adults can either behave selfishly by keeping the resources they forage or they can pool them, subsequently dividing the pooled resources after each round of foraging. We found that fairness as equitability was beneficial especially when resources were large but difficult to obtain and led to the evolution of Fp. We conclude by discussing the implications of this model, for developing more rigorous theory on the evolution of social play, and future directions for theory development by modeling the evolution of play.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2018.01167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066575PMC
July 2018

Juvenile social experience and differential age-related changes in the dendritic morphologies of subareas of the prefrontal cortex in rats.

Synapse 2018 04 21;72(4). Epub 2017 Dec 21.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

Juvenile social interactions have been shown to influence the dendritic complexity of neurons in the prefrontal cortex (PFC). In particular, social play induces pruning of the cells in the medial prefrontal cortex (mPFC), whereas interacting with multiple partners, whether those interactions involve play or not, increases the complexity of cells in the orbital frontal cortex (OFC). Previous studies suggest that these changes differ in their stability during adulthood. In the present study, rats were reared in groups of either four (quads) or two (pairs) and the brains of the rats from each rearing condition were then harvested at 60 days (i.e., shortly after sexual maturity) and 100 days (i.e., fully adult). The rats housed with multiple partners had more complex neurons of the OFC at 60 days and this complexity declined to a comparable level to that of pair housed rats by 100 days. In contrast, the play-induced changes of the mPFC remained similar at both ages. These findings suggest that the changes in the PFC induced by different social experiences in the juvenile period differ in how long they are maintained in adulthood. Differences in the functions regulated by the OFC and the mPFC are considered with regard to these differences in the stability of juvenile-induced neural changes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/syn.22022DOI Listing
April 2018

Avoiding escalation from play to aggression in adult male rats: The role of ultrasonic calls.

Behav Processes 2017 Nov 21;144:72-81. Epub 2017 Sep 21.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

Play fighting is most commonly associated with juvenile animals, but in some species, including rats, it can continue into adulthood. Post-pubertal engagement in play fighting is often rougher and has an increased chance of escalation to aggression, making the use of play signals to regulate the encounter more critical. During play, both juvenile and adult rats emit many 50-kHz calls and some of these may function as play facilitating signals. In the present study, unfamiliar adult male rats were introduced in a neutral enclosure and their social interactions were recorded. While all pairs escalated their playful encounters to become rougher, only the pairs in which one member was devocalized escalated to serious biting. A Monte Carlo shuffling technique was used for the analysis of the correlations between the overt playful and aggressive actions performed and the types and frequencies of various 50-kHz calls that were emitted. The analysis revealed that lower frequency (20-30kHz) calls with a flat component maybe particularly critical for de-escalating encounters and so allowing play to continue. Moreover, coordinating calls reciprocally, with either the same call mimicked in close, temporal association or with complementary calls emitted by participants as they engage in complementary actions (e.g., attacking the nape, being attacked on the nape), appeared to be ways with which calls could be potentially used to avoid escalation to aggression and so sustain playful interactions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2017.09.014DOI Listing
November 2017

"I am going to groom you": Multiple forms of play fighting in gray mouse lemurs (Microcebus murinus).

J Comp Psychol 2018 02 31;132(1):6-15. Epub 2017 Aug 31.

University of Lethbridge.

Play fighting is a commonly reported form of play that involves competitive interactions that generally do not escalate to serious fighting. Although in many species what are competed over are the body targets that are bitten or struck in serious fighting, for many others, the competition can be over other forms of contact, such as sex, social grooming, and predation. In primates, the most detailed studies have been of species such as Old World monkeys, that engage in play fighting that simulates serious fighting, but reports of a number of others, especially among nocturnal prosimians, have noted that play fighting can also involve simulation of sex and grooming. The present study on captive born gray mouse lemurs () provides a quantitative assessment of the relative engagement by juveniles in play fighting involving agonistic and amicable targets. About 80% of play fighting involves competing to groom or mount one another, with a minority involving competing to bite. That these forms of play fighting may be distinct from one another is suggested by the finding that attack on one target does not lead to counterattack on another. The findings are discussed in terms of the evolution and mechanisms underlying play fighting in primates and more widely among animals. (PsycINFO Database Record
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/com0000082DOI Listing
February 2018

Specific 50-kHz vocalizations are tightly linked to particular types of behavior in juvenile rats anticipating play.

PLoS One 2017 3;12(5):e0175841. Epub 2017 May 3.

Dept of Neuroscience, Univ. of Lethbridge, Lethbridge, AB, Canada.

Rat ultrasonic vocalizations have been suggested to be either a byproduct of physical movement or, in the case of 50-kHz calls, a means to communicate positive affect. Yet there are up to 14 distinct types of 50-kHz calls, raising issues for both explanations. To discriminate between these theories and address the purpose for the numerous 50-kHz call types, we studied single juvenile rats that were waiting to play with a partner, a situation associated with a high number of 50-kHz calls. We used a Monte-Carlo shuffling procedure to identify vocalization-behavior correlations that were statistically different from chance. We found that certain call types ("split", "composite" and "multi-step") were strongly associated with running and jumping while other call types (those involving "trills") were more common during slower movements. Further, non-locomotor states such as resting and rearing were strongly predictive of a lack of vocalizations. We also found that the various sub-types of USVs can be clustered into 3-4 categories based on similarities in the way they are used. We did not find a one-to-one relationship between any movements and specific vocalizations, casting doubt on the motion byproduct theory. On the other hand, the use of specific calls during specific behaviors is problematic for the affect communication hypothesis. Based on our results, we suggest that ultrasonic calls may serve to coordinate moment-to-moment social interactions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175841PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414981PMC
September 2017

What is play fighting and what is it good for?

Learn Behav 2017 12;45(4):355-366

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

Play fighting is a common form of play reported among species of mammals, birds, and some other taxa. The competition present in play fighting revolves around gaining some advantage, such as biting a partner without being bitten. The behavior simulated during play fighting need not be restricted to that present in adult serious fighting, but can involve competitive interactions derived from amicable behavior, such as sex and social grooming, or from nonsocial competition, such as predation. What unifies play fighting, irrespective of the functional behavior being simulated, is that it involves some degree of reciprocity, or turn taking, that requires that the competition be attenuated by cooperation. However, there are several different ways in which cooperation can be inserted into playful interactions, and these vary in use across different species. The moderation of competition with cooperation forces animals to monitor their own actions and those of their partners, and this common feature appears to be one vehicle through which the experience of play fighting in the juvenile period can train animals for greater psychological resilience. The monitoring and contextual adjustment of actions influences the development of executive functions of the brain, which, in turn, leads to the development of more adaptable adults.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3758/s13420-017-0264-3DOI Listing
December 2017

Impact of adolescent social experiences on behavior and neural circuits implicated in mental illnesses.

Neurosci Biobehav Rev 2017 05 20;76(Pt B):280-300. Epub 2017 Jan 20.

Department of Psychiatry, Indiana University School of Medicine, 320 West 15th Street, Indianapolis, IN, 46202, USA.

Negative social experiences during adolescence are central features for several stress-related mental illnesses. Social play fighting behavior in rats peaks during early adolescence and is essential for the final maturation of brain and behavior. Manipulation of the rat adolescent social experience alters many neurobehavioral measurements implicated in anxiety, depression, and substance abuse. In this review, we will highlight the importance of social play and the use of three separate social stress models (isolation-rearing, social defeat, and social instability stress) to disrupt the acquisition of this adaptive behavior. Social stress during adolescence leads to the development of anxiety and depressive behavior as well as escalated drug use in adulthood. Furthermore, sex- and age-dependent effects on the hormonal stress response following adolescent social stress are also observed. Finally, manipulation of the social experience during adolescence alters stress-related neural circuits and monoaminergic systems. Overall, positive social experiences among age-matched conspecifics during rat adolescence are critical for healthy neurobehavioral maturation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neubiorev.2017.01.018DOI Listing
May 2017

From Play to Aggression: High-Frequency 50-kHz Ultrasonic Vocalizations as Play and Appeasement Signals in Rats.

Curr Top Behav Neurosci 2017 ;30:91-108

Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.

When rats engage in playful interactions, they emit appetitive 50-kHz ultrasonic vocalizations (USVs). We investigated the role of 50-kHz USVs in the playful behavior of both juvenile and adult rats. A cohort of juvenile rats was surgically devocalized and allowed to interact with either devocalized or intact partners as juveniles and again as adults. A substantial decrease in playful motivation was seen for pairs of devocalized rats, as well as all intact rats housed with devocalized ones. In pairs in which at least one partner could vocalize, there was no difference in the number of playful interactions as compared to controls. Further investigation revealed that, within the playful episode itself, 50-kHz USVs are more likely to appear before a playful attack is launched than after, regardless of the attacking partner's ability to vocalize, and when one partner is pinned on its back by another, it is the rat that is on top that is more likely to emit 50-kHz USVs. These findings suggest that, for juveniles, 50-kHz USVs may have a critical function in maintaining and facilitating playful motivation, but a more limited role in signaling playful actions. In adults, however, whatever the motivational role of such calling may be, the various kinds of USVs appear to serve critical communicatory functions. For instance, when pairs of adult males that are unfamiliar with one another encounter each other in a neutral arena, they play together, but if one partner is devocalized, there is a significantly higher likelihood that the interaction will escalate to become aggressive. While the relative roles of appetitive 50-kHz and aversive 22-kHz USVs in this context remain to be determined, our overall findings for play in both juveniles and adults suggest that 50-kHz USVs likely have multiple functions, with different functions being more prevalent at some ages and contexts than others.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/7854_2015_432DOI Listing
June 2017

Effects of prenatal exposure to valproic acid on the development of juvenile-typical social play in rats.

Behav Pharmacol 2015 Dec;26(8 Spec No):707-19

aDepartment of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta bCanadian Institute for Advanced Research Program in Child Brain Development, Canada.

Autism is a severe neurodevelopmental disorder characterized by qualitative impairments in social behavior, communication, and aberrant repetitive behaviors. A major focus of animal models of autism has been to mimic the social deficits of the disorder. The present study assessed whether rats exposed prenatally to valproic acid (VPA) show deficits in social play as juveniles that are consistent with the social deficits observed in autism. Dams were exposed to an acute dose of VPA on gestational day 12.5. Later, the playful interactions and associated ultrasonic vocalizations of the juveniles were examined. It was predicted that VPA-treated rats should play less than the controls. Characteristic of neurobehavioral insult at this early age, the VPA-treated juveniles showed significant increases in the frequency of body shakes and sexual mounting, but played at the same frequency as the controls. However, when playing, they were less likely to use tactics that facilitated bodily contact and vocalized less. These data suggest that prenatal VPA exposure disrupts some aspects of being able to communicate effectively and engage partners in dynamic interactions - deficits that are consistent with those observed in autism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/FBP.0000000000000169DOI Listing
December 2015

Are 50-khz calls used as play signals in the playful interactions of rats? III. The effects of devocalization on play with unfamiliar partners as juveniles and as adults.

Behav Processes 2015 Apr 30;113:113-21. Epub 2015 Jan 30.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

When playing, rats emit 50-kHz calls which may function as play signals. A previous study using devocalized rats provides support for the hypothesis that 50-kHz function to promote and maintain playful interactions (Kisko et al., 2015). However, in that study, all pairs were cage mates and familiar with each other's playful tendencies that could have attenuated the role of play signals. The present study uses unfamiliar pairs to eliminate any chance for such attenuation. Four hypotheses about how 50-kHz calls could act as play signals were tested, that (1) they maintain the playful mood of the partner, (2) they are used to locate partners, (3) they attract play partners and (4) they reduce the risk of playful encounters from escalating to serious fights. Predictions arising from the first three hypotheses, tested in juveniles, were not supported, suggesting that, for juveniles, 50-kHz calls are not facilitating playful interactions as play signals. The fourth hypothesis, however, was supported in adults, but not in juveniles, in that unfamiliar adult males were more likely to escalate playful encounters into serious fights when one partner was devocalized. These findings suggest that vocalizations at most have a minor role in juvenile play but serve a more central role in modulating adult interactions between strangers, allowing for the tactical mitigation of the risk of aggression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2015.01.016DOI Listing
April 2015

Rough-and-tumble play as a window on animal communication.

Biol Rev Camb Philos Soc 2016 May 25;91(2):311-27. Epub 2015 Jan 25.

Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada.

Rough-and-tumble play (RT) is a widespread phenomenon in mammals. Since it involves competition, whereby one animal attempts to gain advantage over another, RT runs the risk of escalation to serious fighting. Competition is typically curtailed by some degree of cooperation and different signals help negotiate potential mishaps during RT. This review provides a framework for such signals, showing that they range along two dimensions: one from signals borrowed from other functional contexts to those that are unique to play, and the other from purely emotional expressions to highly cognitive (intentional) constructions. Some animal taxa have exaggerated the emotional and cognitive interplay aspects of play signals, yielding admixtures of communication that have led to complex forms of RT. This complexity has been further exaggerated in some lineages by the development of specific novel gestures that can be used to negotiate playful mood and entice reluctant partners. Play-derived gestures may provide new mechanisms by which more sophisticated communication forms can evolve. Therefore, RT and playful communication provide a window into the study of social cognition, emotional regulation and the evolution of communication systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/brv.12172DOI Listing
May 2016

Moderate prenatal alcohol exposure and quantification of social behavior in adult rats.

J Vis Exp 2014 Dec 14(94). Epub 2014 Dec 14.

Department of Psychology, University of New Mexico; Department of Neurosciences, University of New Mexico.

Alterations in social behavior are among the major negative consequences observed in children with Fetal Alcohol Spectrum Disorders (FASDs). Several independent laboratories have demonstrated robust alterations in the social behavior of rodents exposed to alcohol during brain development across a wide range of exposure durations, timing, doses, and ages at the time of behavioral quantification. Prior work from this laboratory has identified reliable alterations in specific forms of social interaction following moderate prenatal alcohol exposure (PAE) in the rat that persist well into adulthood, including increased wrestling and decreased investigation. These behavioral alterations have been useful in identifying neural circuits altered by moderate PAE(1), and may hold importance for progressing toward a more complete understanding of the neural bases of PAE-related alterations in social behavior. This paper describes procedures for performing moderate PAE in which rat dams voluntarily consume ethanol or saccharin (control) throughout gestation, and measurement of social behaviors in adult offspring.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3791/52407DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4396951PMC
December 2014

Are 50-kHz calls used as play signals in the playful interactions of rats? II. Evidence from the effects of devocalization.

Behav Processes 2015 Feb 20;111:25-33. Epub 2014 Nov 20.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

During playful interactions, juvenile rats emit many 50-kHz ultrasonic vocalizations, which are associated with a positive affective state. In addition, these calls may also serve a communicative role - as play signals that promote playful contact. Consistent with this hypothesis, a previous study found that vocalizations are more frequent prior to playful contact than after contact is terminated. The present study uses devocalized rats to test three predictions arising from the play signals hypothesis. First, if vocalizations are used to facilitate contact, then in pairs of rats in which one is devocalized, the higher frequency of pre-contact calling should only be present when the intact rat is initiating the approach. Second, when both partners in a playing pair are devocalized, the frequency of play should be reduced and the typical pattern of playful wrestling disrupted. Finally, when given a choice to play with a vocal and a non-vocal partner, rats should prefer to play with the one able to vocalize. The second prediction was supported in that the frequency of playful interactions as well as some typical patterns of play was disrupted. Even though the data for the other two predictions did not produce the expected findings, they support the conclusion that, in rats, 50-kHz calls are likely to function to maintain a playful mood and for them to signal to one another during play fighting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2014.11.011DOI Listing
February 2015

The role of the medial prefrontal cortex in regulating interanimal coordination of movements.

Behav Neurosci 2014 Oct 11;128(5):603-13. Epub 2014 Aug 11.

Department of Neuroscience, University of Lethbridge.

Rats with juvenile play experience display a greater ability in coordinating their movements with social partners than those deprived of such experience, and this may be due to the play-induced neural restructuring of the medial prefrontal cortex (mPFC). The present study investigates the role of the mPFC in interanimal coordination. Rats with and without bilateral mPFC lesions were tested on a robbing-and-dodging task. This food protection task measures the ability of rats to protect pieces of food by gaining and maintaining an interanimal distance between themselves and the rat attempting to rob the food. Given that mPFC lesions have been associated with sensory and motor deficits, the same rats were also subjected to a task to measure skilled motor movements. Rats with bilateral mPFC lesions had more food stolen and displayed an inability to maintain interanimal distance with partner, but did not exhibit any motor or sensory deficits. These findings suggest that the mPFC is involved in interanimal coordination and that the play-induced neural restructuring of this area may account for the enhanced coordination seen in rats with prior play experience.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/bne0000010DOI Listing
October 2014

Domestication and diversification: a comparative analysis of the play fighting of the Brown Norway, Sprague-Dawley, and Wistar laboratory strains of (Rattus norvegicus).

J Comp Psychol 2014 Aug 21;128(3):318-27. Epub 2014 Apr 21.

Department of Neuroscience, University of Lethbridge.

Laboratory strains of rats are a commonly used subject to study play behavior. Recent research has shown that play in one laboratory strain of rat (e.g., Long-Evans hooded) differs in a number of ways from its wild counterparts. These findings suggest that domestication affects some aspects of play behavior. However, there are multiple strains of laboratory rats, which have been domesticated through different lineages all derived from wild rats and it cannot be assumed that all domestic strains are identical in their play. Therefore, the aim of this study was to compare the play behavior of three other strains of laboratory rats (e.g., Wistar, Sprague-Dawley, and Brown Norway). All strains were similar to each other as they all engaged in high frequencies of play, tolerated similar interanimal distances before initiating playful defense and displayed similar acrobatic capacities, suggesting domestication produces some common changes in play and other factors that influence play. However, strains differed significantly from one another in the use of tactics that promote bodily contact during play. Indeed, in this regard, some strains were more similar to wild rats than others, suggesting that some domestication-induced changes are either unique or more prominent in some laboratory strains than others. Such a mosaic pattern of transformation not only offers the possibility of using strain differences to characterize the genetic factors contributing to different facets of play, but also cautions researchers from making rat-general conclusions from studies on any one strain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/a0036104DOI Listing
August 2014

How domestication modulates play behavior: a comparative analysis between wild rats and a laboratory strain of Rattus norvegicus.

J Comp Psychol 2013 Nov 1;127(4):453-64. Epub 2013 Jul 1.

Department of Neuroscience, University of Lethbridge.

Laboratory rats have been widely used to study the development and neural underpinnings of play behavior. However, it is not known whether domestic rats play in the same way and at the same frequency as their wild counterparts. In this study, the play of juvenile rats from a colony of wild rats maintained in captivity was compared to that of a strain of domesticated rats (e.g., Long Evans hooded). Three predictions were tested. First, it was predicted that wild rats would incorporate more agonistic behavior in their play. This was not found, as in all cases, both the wild and the laboratory rats attacked and defended the nape during play, a nonagonistic body target. Second, because play is typically more frequent in domesticated animals than their wild progenitors, it was predicted that the wild rats should play less than the laboratory rats. This was found to be the case. Third, because wild animals tend to be less tolerant of proximity by conspecifics and tend to be more agile in their movements, it was predicted that there would be less contact between wild pair mates. This was found to be the case; data show that the play of laboratory rats involves the same target (i.e., the nape of the neck) and tactics of defense as those used by wild rats. However, the laboratory rats initiated playful attacks more frequently, and were more likely to use tactics that promoted bodily contact. These similarities and differences need to be considered when using laboratory animals as models for play in general.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/a0032187DOI Listing
November 2013

Peering into the dynamics of social interactions: measuring play fighting in rats.

J Vis Exp 2013 Jan 18(71):e4288. Epub 2013 Jan 18.

Department of Neuroscience, University of Lethbridge.

Play fighting in the rat involves attack and defense of the nape of the neck, which if contacted, is gently nuzzled with the snout. Because the movements of one animal are countered by the actions of its partner, play fighting is a complex, dynamic interaction. This dynamic complexity raises methodological problems about what to score for experimental studies. We present a scoring schema that is sensitive to the correlated nature of the actions performed. The frequency of play fighting can be measured by counting the number of playful nape attacks occurring per unit time. However, playful defense, as it can only occur in response to attack, is necessarily a contingent measure that is best measured as a percentage (#attacks defended/total # attacks X 100%). How a particular attack is defended against can involve one of several tactics, and these are contingent on defense having taken place; consequently, the type of defense is also best expressed contingently as a percentage. Two experiments illustrate how these measurements can be used to detect the effect of brain damage on play fighting even when there is no effect on overall playfulness. That is, the schema presented here is designed to detect and evaluate changes in the content of play following an experimental treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3791/4288DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3582623PMC
January 2013

Obstacle Avoidance amongst Parkinson Disease Patients Is Challenged in a Threatening Context.

J Neurodegener Dis 2013 15;2013:787861. Epub 2013 May 15.

Engineering and Human Performance Laboratory, Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4 ; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 1N4.

We examined whether people with Parkinson disease (PD) have difficulty negotiating a gait obstruction in threatening (gait path and obstacle raised above floor) and nonthreatening (gait path and obstacle at floor level) contexts. Ten PD patients were tested in both Meds OFF and Meds ON states, along with 10 age-matched controls. Participants completed 18 gait trials, walking 4.7 m at a self-selected speed while attempting to cross an obstacle 0.15 m in height placed near the centre point of the walkway. Kinematic and kinetic parameters were measured, and obstacle contact errors were tallied. Results indicated that PD patients made more obstacle contacts than control participants in the threatening context. Successful crossings by PD patients in the threatening condition also exhibited kinematic differences, with Meds OFF PD patients making shorter crossing steps, with decreased initiation and crossing velocities. The findings from this study lend support to the theory that PD patients rely on directed attention to initiate and control movement, while providing indication that the motor improvements provided by current PD pharmacotherapy may be limited by contextual interference. These movement patterns may be placing PD patients at risk of obstacle contact and falling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2013/787861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4437341PMC
August 2015

Introduction to Quo Vadis behavioral neuroscience: a Festschrift for Philip Teitelbaum.

Behav Brain Res 2012 Jun 11;231(2):231-2. Epub 2012 Apr 11.

George Mason University, Department of Psychology, United States.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbr.2012.04.008DOI Listing
June 2012

Closing the circle between perceptions and behavior: a cybernetic view of behavior and its consequences for studying motivation and development.

Dev Cogn Neurosci 2011 Oct 27;1(4):404-13. Epub 2011 Jul 27.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.

The dynamic aspect of behavior is exaggerated during social interactions such as sex, combat and rough-and-tumble play where the movements of the two animals involved continually influence one another. The behavioral 'markers' abstracted from this stream can greatly influence the conclusions drawn about the effects of experimental procedures and how changes during development are interpreted. By using methods of analysis that treat behaving systems as being dynamic and governed by negative feedback processes, the behavioral markers that are abstracted can more accurately reflect the underlying mechanisms. Using examples from rats engaged in play fighting, serious fighting and food defense, it is shown that motivational from non-motivational contributions to behavioral output and changes in that output with age can be discerned. For example, while sex differences in the frequency of initiating play by juvenile rats are shown to reflect differences in the motivation to engage in this behavior, sex differences in preferred motor patterns used during play do not. Rather, they reflect differences in perceptual and motor systems. Although an issue that is often neglected, we show that behavioral description, and the theoretical underpinnings of that description, is critical for the study of the mechanisms that produce and regulate behavior.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dcn.2011.07.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6987549PMC
October 2011

Anatomy is important, but need not be destiny: novel uses of the thumb in aye-ayes compared to other lemurs.

Behav Brain Res 2012 Jun 6;231(2):378-85. Epub 2011 Sep 6.

Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada T1K 3M4.

Aye-ayes (Daubentonia madagascerensis) have highly specialized hands with long digits, especially the thin middle one (D3), which is used for extracting food, such as beetle larvae, under bark. Due to the elongation of their fingers, including the thumb, it is presumed that aye-ayes have a rather limited capacity for delicate manipulation of objects. However, studies have reported independent movement of digits D3 and D4, and one report noted a seemingly independent thumb (D1) movement in holding food. Sixteen captive adult aye-ayes were videotaped feeding on a diverse range of foods so as to document how the thumb is used during food holding. To determine if the patterns observed were unique to aye-ayes, 24 individuals from 9 other species of lemurs were also videotaped. Two patterns of thumb use idiosyncratic to aye-ayes and one other lemur, the sifaka (Propithecus verreauxi), were identified: (1) when holding a food item in one hand, the thumb was used to secure the food, with the other digits playing a secondary role; (2) when holding a food item with both hands, the thumbs once again took a predominant role in securing the food. In the majority of these cases, whether held by one or two thumbs, the thumbs curled around the item, but some descriptive evidence is provided that suggests that aye-ayes exaggerate the role of the thumbs by shifting the hold to the outer edge. The novel uses of the thumbs in aye-ayes demonstrate that brain mechanisms can sometimes override the behavioral (or motor) limitations imposed by the morphology of the body.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbr.2011.08.046DOI Listing
June 2012

The use of the bared-teeth display during play fighting in Tonkean macaques (Macaca tonkeana): sometimes it is all about oneself.

J Comp Psychol 2011 Nov 8;125(4):393-403. Epub 2011 Aug 8.

Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge.

Play signals are viewed as important means by which animals inform each other that bites, strikes, and throws that occur during play fighting are indeed playful rather than serious. One such signal is the open mouth play face that is common in primates and many other mammals. Unfortunately, as most play fighting involves biting, it can be ambiguous as to whether any instance of opening the mouth is performed to communicate playful intent or is simply a preparation for biting. In this study, open mouths co-occurring with the bared-teeth display (teeth-baring) in Tonkean macaques were used to assess the context in which facial gestures only relevant for signaling (i.e., teeth-baring is not necessary for biting) are used during play. Two predictions arising from the hypothesis that play signals are used to facilitate playful contact were tested: that the open mouth with teeth-baring should (1) be most frequent preceding contact, and (2) that it should be performed most often when bites are directed at orientations that is visible to the recipient. The data only partially support these predictions. The open mouth with teeth-baring is also frequently used when a monkey withdraws from playful contact. Moreover, it is associated with bites to body targets, such as the rump, that offer little prospect for detection by the recipient; this supports the possibility that play signals may sometimes be emitted not to communicate with the partner but with the performer itself. Thus, play signals serve multiple functions during play fighting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/a0024514DOI Listing
November 2011
-->