Research

We now know that the brain is a malleable structure—knowledge that inspires both hope and caution.  On the more hopeful side, research indicates that more complex environments enhance neural connections.  However, the “plastic” brain may also transform itself in ways that make us more vulnerable to various forms of mental illnesses such as anxiety disorders and depression.  Below are descriptions of our laboratory’s attempt to understand more about how enriching social environments alter behavior and brain responses (i.e., our maternal and paternal research), as well as our attempts to understand more about adaptive coping strategies when the stress of life can not be avoided.

The Maternal Brain:

In collaboration with Craig Kinsley’s laboratory at the University of Richmond, we have investigated the neurobiological modifications in rats exposed to various forms and durations of maternal experience.  Initially we found that the accumulation of novel stimuli-- such as the visual, auditory, tactile, and olfactory stimuli associated with the new pups—led to more efficient foraging/spatial learning and increased boldness in novel and stressful situations.  Interestingly, in many cases these effects are long-lasting.  We have also found that the rat moms exhibit more focused attention in the attention set shifting paradigm and more efficient responses when hunting for crickets.  Explorations of the effects of maternal experience on the neurobiology of the maternal animals have revealed modifications of cell body size, dendritic connections, and neuroplasticity in key areas of the maternal brain circuit—all pointing to the conclusion that maternal responses lead to more complex and resilient neurobiological modifications.  These maternal-induced brain and behavior modifications likely enhance the female’s ability to protect her offspring—a valuable genetic investment.

The Paternal Brain:

We have also investigated the effects of paternal experience on the brains and behavior of male mice.  For this research we have used the uniquely monogamous and bi-parental species Peromyscus californicus.  These animals stay with the females after they give birth and engage in all parental responses exhibited by the female except lactation.  Similar to our maternal studies, we are finding that these paternal mice also exhibit enhanced foraging and reduced anxiety.  Additionally, non-paternal males who have had limited experience with pups also exhibit neurobiological modifications—namely enhanced responsivity in the brain’s oxytocin and vasopressin systems. Compared to their evolutionary cousins Peromyscus maniculatus, the California mice also show more interest in alien pups, suggesting that the paternal brain circuits are closely tied to social responses extending to pups other than their own.

Flexible Coping and Resilience:

Considering that no mammal is protected from experiencing stress, our laboratory has focused on identifying the most effective coping strategies—leading to diminished allostatic load during chronic stress exposure.  After adapting a coping strategy profile assessment from piglets we are currently determining if young rats are active, passive, or flexible copers.  After exploring brain immunoreactivity, stress hormone levels, cardiovascular responses, and various behaviors in these animals, our data suggest that flexible coping strategies are the most adaptive in our rodent models.  Because the response patterns are less “fixed” in the flexible copers than observed in passive and active coping animals, we have hypothesized that the flexible copers are more in tune with their environments and are more likely to exhibit adaptive responses in subsequent stressful situations

 

First picture was photographed by Doug Buerlein