Margaret McCarthy

Margaret McCarthy received a PhD from the Institute of Animal Behavior at Rutgers University, postdoctoral training at Rockefeller University and was a NRC Fellow at NIAAA before joining the faculty of the University of Maryland School of Medicine in 1993.  She was a professor in the Department of Physiology before becoming the Chair of the Department of Pharmacology in 2011. She has received numerous awards and recognition for her research  and for mentoring of graduate students. McCarthy has a long standing interest in the cellular and molecular mechanisms establishing sex differences in the brain.  She uses a combined behavioral and mechanistic approach in the laboratory rat to understand both normal brain development and how these processes might go selectively awry in males versus females and has discovered numerous novel signaling processes along the way. 

Surprising origins of sex differences in the brain

Elucidating the cellular and molecular mechanisms by which sex differences are developmentally programmed into the brain has been a central goal of neuroendocrinology since the discipline was formed half a century ago. Neuroanatomical sex differences range from cell number, to phenotype to dendritic morphology and synaptic patterning.  Research emphasis has largely been on the intersection of steroids, neurotransmitters and growth/survival factors. Our laboratory has found a central role for a different source of neuromodulation, the neuroimmune system, and has discovered that at least two immune cells, microglia and mast cells, are critical partners in the process of brain masculinization. We further find that membrane derived signaling molecules, in particular the prostaglandins and endocannabinoids, are also essential drivers of the sexual differentiation process by modulating the activity of immune cells in the brain.  Why males have higher levels of all of these is a mystery but may have its origins in the maternal immune system and its response to male fetuses during mammalian gestation.