Exposure to gestational stress as a translational model for postpartum depression
Becoming a mother is usually regarded as one of life’s most emotionally positive and rewarding experiences but for a significant number of women, the postpartum period can instead be a difficult time accompanied by mental illness. Indeed, recent analyses indicate that at least 15% of new mothers worldwide each year are affected by postpartum depression (PPD). Although PPD is common and known to be detrimental for maternal well-being and to adversely affect mother-infant interactions, the neurobiology of PPD is understudied and thus poorly understood. 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 maternal 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 qPCR, Western blot and ELISA