Dr. Rebecca Shansky
Professor Northeastern University Postdoctoral Researcher Mount Sinai School of Medicine
PhD Yale University
During college, Dr. Rebecca Shansky was “living the liberal arts dream” – taking classes in literature, art, Eastern religion, film, psychology…but no basic science. That is, until she took a behavioral neuroscience class during her junior year that was required for her psychology major, and suddenly she was hooked. She took as many neuroscience classes as she could in her remaining time in college and started doing some research in a behavioral neuroscience lab as part of work-study. She has been doing research ever since. Today, Rebecca is a Professor in the Department of Psychology at Northeastern University, doing groundbreaking work on sex differences in stress-related neural circuits.
After enjoying her first behavioral neuroscience research experience during college, Rebecca was encouraged to pursue a PhD, so she applied to and joined the graduate program in Neurobiology at Yale University. She felt very behind, not having a strong basic science background and not fully knowing what graduate school would entail. Nevertheless, she knew she loved rodent behavioral neuroscience and was particularly excited about the prospect of doing animal research with relevance to mental illness. That interest led her to join the lab of Dr. Amy Arnsten, who was studying stress. Amy had a small, internal grant to look at sex differences in the effects of stress on working memory performance in rats, and Rebecca was more than happy to take that on as her thesis project. This proved to be fortuitous, as it set the course for much of the rest of her career in exploring sex differences in brain and behavior. Her findings of striking sex differences in stress responses — specifically, that female rats had a lower threshold for stress-induced cognitive deficits — were significant and surprising. Most behavioral neuroscience labs at the time were exclusively studying males and assuming that everything would pretty much be the same in females (just without all those messy hormones!). Rebecca’s work highlighted the importance of studying both male and female animals in order to gain a full understanding of diverse brain function, such as in response to stress.
Excited about her findings and eager to dig further into sex differences in the brain, Rebecca decided to do a postdoc. In contrast to some other transition points in her career, this one proved to be remarkably smooth. She wanted to move back to New York and to get deeper into the brain after having primarily focused on behavior and pharmacology during her PhD. She reached out to Dr. Bruce McEwen at Rockefeller University, who was studying how stress impacts neuronal structure and circuit function. Fortunately, he had just received a big collaborative grant with Dr. Joseph LeDoux at NYU and Dr. John Morrison at Mount Sinai that provided funding for a postdoc. Rebecca applied and got the job. She began working primarily with John Morrison at Mount Sinai with co-advising support from the other two PIs, and she delved into her project exploring how chronic stress affects neuronal structure.
It was already known that in brain areas such as the hippocampus and prefrontal cortex, chronic stress reduces dendritic material in male rats – in other words, neurons shrink and lose some of their ability to receive information. Given Rebecca’s PhD findings of exacerbated stress responses in females, the obvious hypothesis was that dendrites in females would shrink even more. To her great surprise, she found the opposite: prefrontal cortex neurons projecting to the amygdala actually got bigger in chronically stressed females. This highlighted for her the importance of thinking about what it means for a system to be adaptive or maladaptive and that in many instances, “getting bigger” can be just as maladaptive as “getting smaller”. Moreover, this provided yet further evidence of how diverse the brain’s responses can be to experiences such as chronic stress and how much of that diversity the field had been missing out on by only studying males.
It was clear that there was much still to be understood about the diversity of brain function and behavior across the sex spectrum, and Rebecca was motivated to start her own lab in order to explore these many questions. However, this transition proved to be much rockier than the one from her PhD to her postdoc. First, there’s a greater bottleneck at this particular transition point – many fewer PI positions exist than postdocs, and thus obtaining a faculty position is intensely competitive. For Rebecca, it took more time to acquire the publications she felt she needed to be truly competitive. The subject of sex differences was still new and unfamiliar to much of the field, so publishing much of her work proved to be challenging as many of the journals “just weren’t quite sure what to do with it." Meanwhile, her postdoc funding provided by her PIs’ collaborative grant wasn’t limitless, and it eventually ran out once the grant ended. Thus, there were a few months when Rebecca was unemployed while applying to faculty positions, which was both practically and existentially stressful. Thankfully, a unique opportunity presented itself whereby a brand new lab at Columbia University, run by Drs. Alex Dranovsky and David Leonardo, was happy to hire her for as little or as long as she wanted in order to benefit from her expertise and help get the lab up and running. This helped hold her over while she was in the process of applying for jobs and ultimately securing a position at Northeastern University in Boston.
Upon starting her own lab at Northeastern, Rebecca envisioned studying sex differences in neuronal structure and function underlying fear conditioning and extinction. But interestingly, her nascent lab found that even the expression of fear was different between males and females. “Time spent freezing” is a common metric of fear expression, but once again, this was based on countless studies focusing solely on males. It turns out that females less reliably freeze when afraid, instead responding in a more active manner (e.g., by “darting”). Thus, her lab is investigating the circuits that underlie this sex-dependent expression of fear, as well as other projects about sex differences in endocannabinoid signaling, interactions between estrogen and dopamine-mediated learning, and more.
Rebecca sees her lab not only as contributing to the scientific body of knowledge, but also as engaging in a broader conversation about how to go about conducting behavioral neuroscience research. “There’s more to what we’re doing than just our own research,” she reflects. To this end, Rebecca has also authored a number of important opinion pieces, such as a widely shared and cited perspective for Science titled “Are hormones a ‘female problem’ for animal research?”. She finds it immensely gratifying to see how the field has been changing as a result of the NIH’s “Sex as a Biological Variable” mandate and to feel like she’s played some part in that. While every neuroscientist may hope to add to or change what we know about the brain, it’s not every day that a body of research changes how we go about studying the brain in the first place – yet Rebecca’s has done just that.
Find out more about Rebecca and her lab’s research here.
Listen to Meenakshi’s full interview with Rebecca on August 30, 2023 below!
