Research in the Kelly lab combines conceptual and empirical tools from comparative neuroanatomy, developmental psychology, behavioral ecology, and molecular neuroscience to understand the proximate and ultimate causes of social behavior.
In a nutshell, we are interested in all things social! Below are brief descriptions of some of the different research trajectories in the lab.
Neuroscience of complex societies
Numerous species, including herds of wildebeest, flocks of birds, and pods of dolphins, live in large groups. Humans, however, are the epitome of this among mammals, with complex societies spanning the globe. Yet, we know surprisingly little about how the brain promotes large group-living. The majority of neuroscience studies examining social behavior focus on bonding in reproductive contexts, such as parent-offspring or mating bonds. While there are certainly reproductive social interactions in large group-living species, there are also numerous social interactions that occur in a nonreproductive context. For humans, we refer to such bonds as friendships, acquaintances, or professional interactions. The primary goals of this line of research are to understand how the brain regulates interactions between individuals in such non-reproductive contexts and to examine how the brain facilitates large group-living and social stability.
Aubrey M. Kelly
Environmental Influences on Behavior
What types of environmental (social and/or physical) stimuli impact social behavior and neural function? And how plastic (i.e., flexible) is social behavior and the social brain once animals are adults? Do certain experiences have more lasting effects than others?
We conduct experiments where we manipulate either the social environment (i.e., group size, exposure to unrelated neighbors) or the physical environment (i.e., temperature, water availability, etc.) in early development or in adulthood to determine how specific environmental factors influence social behavior and underlying neural and physiological mechanisms.
Understanding how one's social environment influences how we behave and can produce long-lasting effects on the brain can provide translational insights important for mental health. Additionally, as the climate continues to change, having an understanding of how physiology, the brain, and behavior may be influenced by changing environmental pressures has the potential to aid in conservation efforts.
The ability to rapidly adapt behavior to best fit a particular social context is crucial to the survival of many animals. In humans, behavioral flexibility facilitates social competence and bolsters interpersonal relations such as aiding in the maintenance of healthy relationships and coping with uncertainty in socially dynamic situations. Therefore, seeking to understand the neural mechanisms that allow individuals to exhibit rapid context-specific responses can not only inform us about complex ways in which the brain has evolved to handle dynamic environments, but it also has translational relevance and can provide insight into mechanisms that promote psychological flexibility in humans.
We conduct experiments in Mongolian gerbils, which readily exhibit rapid changes in prosocial and antisocial behavior when interacting with a pairbond partner vs. an intruder, respectively. Using techniques such as classic endocrine manipulations and state-of-the-art technology (i.e., fiber photometry), we are
examining how peripheral steroids influence neurosteroid mechanisms and other systems (i.e., the nonapeptide system) to produce rapid changes in behavior.
Calcium signaling via fiber photometry
Mapping Social Neural Circuits
Complex social behavior isn't the result of activity in one region of the brain. Rather, behavior is the result of multiple brain regions and multiple cell types working in concert. We seek to understand how the brain produces behaviors such as gregariousness (a preference to affiliate in large groups), general affiliation, and aggression. Using behavioral and immediate early gene (IEG) studies, pharmacological manipulation, and viral technology (i.e., tracing, CRISPR, and DREADDs), we aim to map neural circuits underlying various types of social behavior.
Additionally, we examine how different neural systems interact to modulate behavior. For example, we are interested in how nonapeptides act as neuromodulators and influence the dopaminergic system to play a role in social reward.
Applying a comparative approach
to understand social behavior
If we are to truly understand the evolution of social behavior, we must consider the fact that various aspects of social behavior evolved independently many times. Thus, we cannot assume that relevant mechanisms have evolved similarly in all species. In order to build a solid foundation on which we study behavior and the underlying mechanisms, we must consider several important factors. Principally, we must use comparative approaches to examine a diversity of species within and across taxa. Doing so will ultimately determine the fundamental principle components for particular social behaviors. On the other hand, and equally important, we must consider the behavioral ecology of an organism and how this shapes components of social behavior. This approach helps explain the significant species-specific subtleties that govern the same behaviors. A combination of these approaches will ultimately provide a picture of the primary evolutionary drivers for those behaviors, both in terms of identifying unifying principles that generalize across taxa, and the singularities that make animals different. Without a fundamental baseline that captures the similarity across taxa, comparisons lack reference. To this end, our research incorporates the use of multiple social species across taxa.
Teaming up with colleagues who work with a variety of species across numerous taxa and have expertise in different areas of ecology, behavior, endocrinology, and neuroscience can lead to the development of a comprehensive body of work that examines the evolution of behavior that considers the whole organism (i.e., feedback between the brain and the periphery) and its environment in a manner that is often not feasible within a single laboratory. Thus, the Kelly Lab is always open to collaboration – please feel free to reach out to us if you are interested in developing a collaboration.
ANIMALS IN THE LAB
Spiny mice are precocial rodents found throughout Africa, the Middle East, and southern Asia. They are primarily studied for their late-gestational development and their remarkable regenerative abilities (i.e., they can regenerate skin and musculoskeletal tissue). We are interested in spiny mice because of their highly social nature. Spiny mice are communal breeders and socially cooperative that offer opportunities for studying mammalian grouping behavior, cooperative behavior, neurodevelopment, and neuroplasticity.
Mongolian gerbils are a socially monogamous rodent that hail from grasslands and shrublands of China, Mongolia, and Russia. Although gerbils have been used in science since the late 1800s, they are a surprisingly uncommon study organism today. Gerbils are primarily used for examining the auditory system and studying epilepsy. Spiny mice are more closely related to gerbils than mice, and thus Mongolian gerbils serve as a less social relative for comparative studies. An added bonus is that the gerbils are quite friendly and a delight to work with!
Prairie voles are a well-studied, socially monogamous rodent native to the central and mid-western United States and south-central provinces of Canada. Numerous field studies have resulted in a rich literature on their natural history and behavioral ecology. Importantly, they share some relatively rare, but defining, behaviors with humans – social monogamy and biparental care. Prairie voles have become quite popular for translational social neuroscience and are an emerging model organism for understanding the neurobiology of attachment and bonding (primarily monogamous pair-bonds and parent-offspring bonds). Various molecular tools have been developed for prairie voles over the last decade, so despite prairie voles not representing a traditional laboratory rodent, state-of-the-art technology is available for asking cutting edge questions in this species.
*Although we are currently finishing prairie vole projects, the lab no longer maintains a prairie vole breeding colony.
Estrildid finches are found throughout the Old World tropics and Australasia. They exhibit an array of social phenotypes, ranging from highly territorial to highly social. Some species are solitary and affiliate only with their pairbond partner whereas other species flock in groups of hundreds. Thus, this family of birds lends itself well to the study of the evolution of sociality. Dr. Kelly’s past research in violet eared waxbills, Angolan blue waxbills, and zebra finches elucidated both convergent and divergent neural mechanisms that modulate grouping behavior. Highly social estrildids, such as zebra finches, are also an excellent model for translational social neuroscience given that they exhibit behaviors similar to humans: communal living, social monogamy, and biparental care. Although the Kelly Lab does not currently have ongoing finch studies at Emory, Dr. Kelly worked with estrildid finches for nearly a decade, and eagerly awaits the day to have the opportunity to return to working with birds – either in the lab or through outside collaborations.