Neuroscience Seminar Series: Heidi Meyer

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Hosted by Janine Kwapis, the seminar is open to faculty, students, staff, other researchers, and the general public.

Abstract

Fear is a fundamental and adaptive process, enabling organisms to detect and respond to threat. However, adaptive behavior requires that fear be flexibly balanced with safety, allowing individuals to suppress defensive responses when danger has passed. Despite its importance for mental health, the neural mechanisms supporting safety learning (and their development across the lifespan) remain poorly understood.

In this talk, I will outline a framework for conceptualizing safety learning, discuss how it is modeled experimentally, and describe what safety looks like behaviorally and neurally in both adult and adolescent animals, including emerging sex differences. Adolescence represents a sensitive period in which fear responses are heightened and anxiety disorders frequently emerge. Paradoxically, this developmental stage may also represent a sensitive window for safety learning, making it especially important to understand how fear-safety balance is established at the circuit level. I will review current models of the neural circuitry supporting fear inhibition and present work from our lab demonstrating a ventral hippocampus-prefrontal cortex circuit that regulates safety learning in both adolescents and adults.

Finally, I will discuss two open questions that follow from this work: which inhibitory populations in prefrontal cortex mediate hippocampal safety signals, and whether fear and safety are encoded by the same neurons via flexible gain control or by distinct, parallel ensembles. I will conclude by highlighting ongoing work showing that developmental engagement of hippocampal safety ensembles can bias long-term fear regulation, with implications for understanding vulnerability and resilience to anxiety across development.

About the Speaker

Dr. Heidi Meyer is an Assistant Professor of Psychological and Brain Sciences at Boston University, where she leads a research program investigating how fear and safety learning are implemented in the brain across development. Her lab combines behavioral models of affective learning with systems neuroscience approaches including circuit-level recordings and activity-dependent methods in mice to understand how neural circuits support flexible regulation of defensive behavior. A central focus of her work is adolescence, a sensitive developmental period characterized by heightened fear and vulnerability to anxiety, but also increased plasticity for learning about safety. Through this work, Dr. Meyer aims to identify mechanisms that promote adaptive emotional regulation and resilience throughout the lifespan.