How the Immune System May Shape Behavior

Title of Project: Complement convertase imaging techniques for optimization of complement therapeutic amelioration of antibody mediated rejection

Reesha Patel, PhD, is assistant professor of Psychiatry and Behavioral Sciences and of Neuroscience. She recently received her first R01 grant to study allergic inflammation and neural circuit function.

Tell me about the grant you received.

This is a five-year R01 from the National Institute of Mental Health (NIMH) under the Stephen I. Katz Early Stage Investigator Research Project Award (PAR-24-075), a mechanism that supports ESI investigators proposing research in an area distinct from their prior work. The total award is approximately $3.49 million in estimated total costs over five years, beginning April 2026.

What are the aims of the project?  

The project asks how allergic inflammation reshapes brain circuits to drive avoidance behaviors, a core feature of mood and anxiety disorders. We focus on interleukin-4 (IL-4), a signaling molecule elevated during allergic responses, and its actions in the medial prefrontal cortex (mPFC) and its projections to the basolateral amygdala (BLA).

There are three aims:

• Aim 1: Map the relationship between mPFC IL-4 levels, the cells producing it and avoidance behavior during allergic inflammation, including how IL-4 shapes mPFC–BLA circuit responses.
• Aim 2: Test whether IL-4 acts as a non-classical neuromodulator of mPFC microcircuits, to define how it tunes interneuron and pyramidal cell activity.
• Aim 3: Determine whether IL-4 receptor signaling in the mPFC is necessary for allergic inflammation, driven changes in mPFC-BLA activity and avoidance behavior.

What are your next steps? 

Right now, we're in the setup phase, establishing the allergic inflammation model, building the tools for cell-type-specific IL-4 manipulations and recruiting a postdoc to lead the project.

What do you hope will come out of this funded research? 

Allergic disease affects a huge fraction of the population, and there's growing evidence it carries a mental health cost that we don't yet understand mechanistically. My hope is that this work reframes IL-4 as a brain signaling molecule, not just an immune one, and reveals how peripheral immune states reach into prefrontal circuits to shape behavior. If we can pinpoint where and how IL-4 acts in the brain, that opens the door to immune-based therapeutic strategies for the avoidance symptoms that cut across mood and anxiety disorders.

Learn more about the project here.