Fenna Krienen, Ph.D.

Research

My lab will explore whether sex differences shape how the brain’s resident immune cells influence neural development and behavior. Immune cells called microglia play a role in sculpting neuronal circuits, particularly in brain regions that show marked differences between males and females. In previous work, we made the surprising discovery that in marmosets, fraternal twins—which develop from different fertilized eggs but share a placenta—are born with a mixed set of microglia: although many of the cells are “native” to the individual, a sizable portion also comes from the twin. Now, taking advantage of this naturally “chimeric” or mixed cell distribution, we will use state-of-the-art methods in immunology, single-cell genomics, and behavioral analyses to determine how the “sex” of microglia (whether the cells carry XX or XY chromosomes) contributes to the development of male versus female brains. My group will also assess whether immune challenges such as maternal infection during pregnancy affect microglial activity or the subsequent social behavior of offspring, work that could lead to new treatments for neurodevelopmental disorders, including those that affect social interactions.