Current research projects include human and animal investigations into individual differences in the biobehavioral effects of stress.  

Our human studies focus on the examination of sex differences in neuroendocrine and immunologic responses to stress in humans.   In particular, we are interested in the role of posterior pituitary hormones, such as oxytocin,  and cytokines (IL-1B and IL-6) in moderating biobehavioral responses to stress in men and women.   This research, funded by the National Science Foundation, is based on  a new stress theory -- a biobehavioral response we label “tend-and-befriend” (Taylor, Klein, et al., 2000), which is a biobehavioral pattern of stress responses that includes the creation and maintenance of social networks and nurturant activities designed to protect the individual and their offspring.   Other human studies in our lab include investigating the stress-mediating effects of nicotine and caffeine on neuroendocrine, immune, and cognitive responses in men and women.  Portions of this research are funded by the Office of Naval Research and are being conducted in collaboration with colleagues in the Penn State University School of Information Sciences and Technology.

Our animal research is designed to investigate biological stress mechanisms that are difficult to study in humans.  Specifically, we design animal models that are believed to parallel the human stress condition.  We currently are investigating the influence of adolescent nicotine exposure (a potent biological stressor) on drug abuse in adulthood.  Our laboratory was the first to develop an animal model of the epidemiologic report that kids who smoke are more likely to use drugs as they get older (Klein, 2001).  Together with Dr. David Vandenbergh from the Department of Biobehavioral Health and the Center for Developmental and Health Genetics, we now are examining gene responses to nicotine exposure in reward-relevant brain regions to determine underlying mechanisms for the development of drug addiction.