By Lauren Quinn
“Autism […] is one of the most gender-biased of all disorders actually worldwide,” stated Dr. Margaret M. McCarthy.
Dr. McCarthy, Director of UM-MIND at the University of Maryland, spoke in Stretansky Hall at 7:30 p.m. on Wednesday, November 5 as Susquehanna’s 2025 Claritas Distinguished Speaker in Science.
McCarthy received both her bachelor’s and master’s degrees in biology and went on to earn her PhD in behavioral neuroscience. She now works in the department of Pharmacology at the University of Maryland’s School of Medicine and is the director of the university’s Medicine Institute for Neuroscience Discovery (UM-MIND).
The title of McCarthy’s speech was “Multifaceted Origins of Sex Differences in the Brain.”. She discussed the differences between males and females concerning nervous system disorders and playfulness.
“Boys are much more likely to be diagnosed with neuropsychiatric or neurological disorders with their origins in development,” stated McCarthy. She elaborated that male disorders tend to originate at birth or during development, while female disorders tend to develop later on in life.
Autism is one disorder that primarily shows up in males, as well as schizophrenia.
“Young men are significantly more likely to be diagnosed with schizophrenia, they’re also more likely to have very negative outcomes, whereas then there is a late in life, sort of perimenopausal, onset of schizophrenia more frequently in women,” said McCarthy.
To study disorders in a laboratory setting, McCarthy explained that mental health disorders typically lead to some sort of social behavior impairment, which can be studied in lab rats.
“We turn to animal models to explore the biological basis of brain sex differences.”
McCarthy explained her process of injecting testosterone into newborn female rat pups to cause the brain to be more male-oriented and “induce brain masculinization.”.
The behaviors that are affected later in life by the increased testosterone include social play, mating, and aggression.
McCarthy’s research focuses on what testosterone is doing to change the behavior of specifically social play.
In rats, social play occurs “only during a restricted developmental period, which is post-weening and prior to puberty […] so it is the first independent social behavior away from mom,” explained McCarthy.
She said that in almost every species, play tends to be more obvious and prominent in males, including rats. However, through research she has discovered that play is as actively programmed in the female rat brain than it is the male rat brain.
In McCarthy’s lab, they use Artificial Intelligence and pose-estimation technology to accurately and efficiently track play behaviors in rats. This allows for grad students to not have to sit and watch video footage of rats playing for hours on end while recording their play behaviors.
McCarthy stated that the technology has assisted with coming to conclusions such as when rats have been isolated for a long time, they are likely to play more intensely when reunited with a playmate.
Just like humans, rats miss each other when they’re apart.
From neurological disorders in people to play behaviors in rats, McCarthy’s captivating speech explained why and how each gender is necessarily unique.