Fear and anxiety are essential for survival. Adequate reactions to anticipated and perceived threats strongly depend on the current state, context and previous experience. What are the neurobiological mechanisms that underlie these adaptive behaviors? While synaptic circuits are the backbone to process threat signals and transform them into behavioral responses, increasing evidence suggests that neuropeptides tune these synaptic circuits in a state- and context-dependent manner, thus allowing for temporal control of excitability and plasticity. Neuropeptide receptors are abundantly expressed in neuronal circuits that regulate fear and anxiety. In fact, recent evidence suggests that most neurons synthesize multiple neuropeptides and, in turn, are regulated by multiple neuropeptide receptors that are expressed in highly cell type-specific patterns. Indeed, genetic alterations in humans as well as pharmacological and genetic experiments in mice indicate important roles for multiple neuropeptides in regulating fear and anxiety and, if dysfunctional, increasing the risk for multiple neuropsychiatric disorders. However, due to the lack of specificity of existing tools, the circuit mechanisms underlying these effects are largely unknown.
In this proposal we aim to reveal cell type-specific neuropeptidergic signaling mechanisms for context-dependent regulation of cortical circuit activity, cellular excitability and synaptic plasticity. We are developing and using cutting-edge in vivo imaging and genetic manipulation tools to reveal how these neuropeptidergic signaling mechanisms regulate behavioral responses in the context of fear and anxiety.
