The Gross group is interested in understanding, at a molecular and circuit level, the neural control of instinctive fear-related behaviour. The goal of our research is to form novel hypotheses about how human instinctive behaviour is controlled, which could form the basis for clinical research to develop improved diagnostic and therapeutic tools for mental illness.

Fear is a mental state elicited by exposure to threats or cues that signal those threats and is a critical survival mechanism that promotes defensive behaviours and decision-making capacities that help us avoid harm. However, in its pathological form, fear can become excessive or inappropriate – features associated with a wide variety of mental disorders. In mammals, the amygdala plays a central role in processing threat stimuli, which are then integrated by downstream hypothalamic and brainstem circuits to produce appropriate defensive behaviours. However, it remains unclear how threat cues drive the formation of internal neural states in these structures to trigger or bias an animal’s defensive behaviours. Our team has shown that distinct amygdala outputs and downstream circuits are recruited in response to different types of threat, with defensive responses to painful stimuli, predators, and bullies mediated by distinct pathways (Gross & Canteras, Nat Rev Neurosci 2012; Silva et al., Nat Neurosci 2013; Montardy et al., Brain Struct Funct 2020). These data suggest that pathological fear is likely to come in different flavours and may be amenable to selective therapeutic treatment. Current work in the group is aimed at understanding how hypothalamic and brainstem circuits transform information about threat stimuli to trigger defensive behaviour, and how this process is remodelled by social experience and context (Masferrer et al., J Neurosci 2020; Krzywkowski et al., eLife 2020).