Mazen Kheirbek, PhD

Assistant Professor

Neural circuits for emotional behaviors

Our primary goal is to delineate the neuronal circuits that underlie emotional behavior. In particular, we are interested in those circuits that are disrupted in mood and anxiety-related disorders. Our main focus is the hippocampus, which, in addition to its role in learning and memory, has become increasingly implicated in the pathophysiology of anxiety disorders. We take an integrative approach; applying novel technologies to both monitor and control genetically identified neural networks in real time. For example, we recently used optogenetic techniques to dissect the functional heterogeneity of the hippocampus along its dorsoventral axis.  We showed that the dorsal pole plays important roles in exploratory behavior and contextual processing, while the ventral pole drives anxiety-related behavior.
Our current efforts are focused on dissecting the mechanisms by which distributed neural circuits generate affective behaviors.  In one line of research, we are focused on understanding the role of the ventral hippocampus in behavior. Specifically, we are mapping the neuronal subtypes, projection streams and the subcortical targets of the ventral hippocampus to determine how this network controls fear and anxiety-related behavior. In a complementary line of research, we are investigating how the dentate gyrus subfield of the hippocampus processes information about contexts with varying emotional valences  - for instance, how is a fear-inducing context encoded differently than a safe one? Here, we are especially interested in the role of adult hippocampal neurogenesis--the incorporation of new neurons in the adult dentate gyrus--plays in the encoding and retrieval of fear memories. To address these questions, our group employs a variety of in vivo techniques. Currently, we use cell-type specific Ca2+ imaging (both miniaturized microscopes and 2-photon imaging), behavioral, electrophysiological, and optogenetic techniques.

Current Projects

1. How does the hippocampus modulate subcortical circuits to control anxiety-related behavior?

2. What is the functional relevance of adult neurogenesis in the dentate gyrus to behavior and local circuit function?

3. How does the ventral hippocampus encode innately aversive environments?

4. How are emotionally salient stimuli represented in the hippocampus, and how does emotional state modulate hippocampal function?

5. How does the early-life development of limbic circuits impact adult emotional behavior?

Lab Members

Jeremy Biane, PhD
Postdoctoral Fellow

Nick Woods
Neuroscience Graduate Student

Kelsey Clausing

Annie Erickson

Lab Website