In the lab we use a procedure referred to as Pavlovian threat conditioning (PTC) to create ‘emotional memories’ in rodents so we can study the brain molecules, cells and circuits that underlie responses to threat in health and disease. Recently, we discovered that the activity of neurons in the hypothalamus, known collectively as the orexin (or hypocretin) system, is important for the formation of implicit memories about cues that warn of danger. We speculate that the orexin system may strongly influence normal reactions, as well as pathological overreactions, to environmental stimuli.
In the lab we are also interested in the brain and behavioral mechanisms underlying active responding (versus passive responses such as freezing) to threats. To study this, we use a Signaled Active Avoidance (SAA) behavioral paradigm in which animals can learn to avoid imminent threats. We recently found that interactions between two key brain areas important for emotion and responses to emotional stimuli, the amygdala and the nucleus accumbens, respectively, are important for SAA. Moreover, we have also found the orexin system plays an integral role in motivating SAA behavior.
Understanding the brain mechanisms of coping, both passive and active, is the ultimate goal of our work. In the long term, we hope that this work will lead to better therapies for individuals suffering from anxiety and stress-related disorders.