The Leuner Laboratory is primarily interested in the maternal brain and behavior. Our research seeks to identify the neurobiological mechanisms underlying changes in emotional, cognitive, parental and motivational functioning during motherhood. Toward this end, the following projects are currently being pursued in the lab:
- The effects of motherhood on prefrontal cortex structure and function
Motherhood is a life altering event accompanied by a host of behavioral and neural changes. We have found that the postpartum period is associated with neuronal growth in the prefrontal cortex and enhanced cognitive flexibility. We are interested in identifying how pregnancy, mothering and hormones contribute to these changes in prefrontal cortex structure and function during the postpartum period.
- Oxytocin and postpartum anxiety
New mothers often undergo substantial modifications in their emotional regulation and mood states that influence the interactions they have with their young. For many, this involves a positive change in mood that includes decreased anxiety mediated, at least in part, by the neuropeptide oxytocin. However, it is not fully understood where and how oxytocin acts in the brain to lower anxiety during the postpartum period. We are currently exploring the possibility that oxytocin interacts with the GABAergic system in the prefrontal cortex to promote maternal anxiolysis.
- Exposure to gestational stress as a translational model for postpartum depression
Not all new mothers experience positive affective change but instead suffer from emotional dysregulation including postpartum depression. Despite the fact that postpartum depression affects up to 20% of new mothers, little is known about the neurobiology of this disorder. To address this issue, my laboratory has developed a rodent model of postpartum depression based on a well-known risk factor, chronic exposure to stress during pregnancy. We have found that postpartum rats exposed to chronic gestational stress exhibit increased depressive-like behavior as well as several other behavioral changes which reflect some of the symptoms seen in depressed mothers including impaired maternal care, cognitive dysfunction and reward-related deficits. Our goal is to understand how stress affects brain circuits that underlie these behaviors in order to elucidate potential mechanisms that may contribute to postpartum depression.
- Neuroimmune alterations in the peripartum brain
There are robust changes in the maternal immune system which are necessary to support a successful pregnancy. To date, these immune changes have been observed in the periphery but a fundamental gap exists in our understanding of whether immune changes extend to the brain to influence behavior. In a collaboration with the Lenz Laboratory, we are investigating how microglia, the primary innate immune cells of the brain, are altered across the peripartum period and following gestational stress. We are also examining their role in maternal care and how they may contribute to stress-induced depressive-like behavior during the postpartum period.
We use a variety of techniques in our research including:
- Behavioral assays to assess cognitive, emotional and social behaviors including attentional set shifting, elevated plus maze, open field, forced swim test, sucrose preference test, social interaction test, conditioned place preference, maternal behavior
- Stereotaxic surgery to provide pharmacological treatments into specific brain regions
- Neuroanatomical techniques such as Golgi and DiI labeling for analysis of neuronal morphology, tract tracing, immunohistochemical and immunoflurorescent staining, brightfield and confocal microscopy
- Molecular biology and biochemical analyses such as Western blot and ELISA.