Going beyond the dyadic paradigm: the dynamics of social play and brain development
| dc.contributor.author | Ham, Jackson R. | |
| dc.contributor.author | University of Lethbridge. Faculty of Arts and Science | |
| dc.contributor.supervisor | Pellis, Sergio M. | |
| dc.date.accessioned | 2025-09-18T19:57:41Z | |
| dc.date.available | 2025-09-18T19:57:41Z | |
| dc.date.issued | 2025 | |
| dc.degree.level | Ph.D | |
| dc.description.abstract | Rough-and-tumble play (RTP) during the juvenile period is critical for developing social competency and some of its associated neural underpinnings in the medial prefrontal cortex (mPFC), yet little is known about how individual variability in play experiences affects development. This thesis investigates whether rats show preferences for specific play partners, what factors influence these choices, and how differences in RTP contribute to behavioral and neural outcomes. Using group play paradigms, I found that rats form partner preferences based on factors such as familiarity, play style, and strain; however, these preferences depend on social context. Indeed, among familiar group members, not all individuals are equally preferred, leading to unequal RTP experiences. The effects of juvenile variability in RTP was assessed by manipulating juvenile experiences and by tracking the life history of individuals reared in groups. Rats reared with a higher-playing strain engaged in less RTP and turn taking than those reared with same-strain partners and later exhibited social deficits and altered mPFC neuron morphology. Similarly, when reared in groups, individuals that naturally engaged in less role reversals during RTP showed impaired social competence and atypical mPFC development. These findings suggest that some rats fail to benefit from RTP. A possible reason for such failure is that early-life influences may impair rat sociability. To explore this, I used neonatal isolation as a model of early life adversity (ELA). ELA did not alter role reversals with familiar partners but reduced both RTP frequency and role reversals with unfamiliar individuals, suggesting that pre-juvenile experiences can indeed impair the mechanisms that maximize the benefits gained from juvenile RTP. Together, these results show that rats preferentially play with certain partners, and this can influence the value of experiences derived from RTP, which combined with individual differences in play cooperation, can shape developmental outcomes. | |
| dc.description.sponsorship | This research would not have been possible without financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC), which provided me with a Canadian Graduate Scholarship. I am also grateful to the University of Lethbridge and the Government of Alberta for their financial support throughout my studies. | |
| dc.embargo | No | |
| dc.identifier.uri | https://hdl.handle.net/10133/7137 | |
| dc.language.iso | en | |
| dc.publisher | Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience | |
| dc.publisher.department | Department of Neuroscience | |
| dc.publisher.faculty | Arts and Science | |
| dc.relation.ispartofseries | Thesis (University of Lethbridge. Faculty of Arts and Science) | |
| dc.subject | social play | |
| dc.subject | brain development | |
| dc.subject | rough-and-tumble play | |
| dc.subject | juvenile rats | |
| dc.subject | medial prefrontal cortex | |
| dc.subject | group play paradigms | |
| dc.subject.lcsh | Dissertations, Academic | |
| dc.subject.lcsh | Play behavior in animals--Research | |
| dc.subject.lcsh | Brain--Growth--Research | |
| dc.subject.lcsh | Social skills | |
| dc.subject.lcsh | Prefrontal cortex--Research | |
| dc.subject.lcsh | Rats as laboratory animals | |
| dc.subject.lcsh | Rats--Infancy--Behavior--Research | |
| dc.subject.lcsh | Rats--Play behavior--Research | |
| dc.title | Going beyond the dyadic paradigm: the dynamics of social play and brain development | |
| dc.type | Thesis |