We use a simple procedure referred to as Pavlovian threat conditioning (PTC) to create ‘emotional memories’ in rodents so we can study the cells, circuits and molecules that underlie responses to threat in health and disease. We discovered that a population of neurons in the hypothalamus, known as orexin or hypocretin cells, are important for the formation of implicit memories about cues that warn of danger. We speculate that the activity of these orexin cells may strongly influence normal reactions, as well as pathological overreactions, to environmental stimuli.
Another procedure we use in the lab, Signaled Active Avoidance (SAA), allows us to study the brain mechanisms underlying the avoidance of threat or harm. Using this procedure, we found that interactions between the amygdala and the nucleus accumbens are important for driving avoidance behaviors.
We will continue to study the role of orexin cells and amygdala-accumbens interactions, with the goal being that with better understanding of these circuits we may find better treatments for individuals suffering from anxiety and stress-related disorders.