Dr. Emily Jacobs
Professor, University of California, Santa Barbara
Postdoctoral Fellow, Harvard Medical School
PhD, University of California, Berkeley
To Dr. Emily Jacobs, the brain is a dynamic endocrine organ—one that is in constant conversation with the body’s shifting hormonal tides. Through precision brain imaging, data sharing, and a commitment to interdisciplinary collaborations, she is building both the knowledge and infrastructure that neuroscience needs to understand women’s health across every stage of life. In doing so, Emily is challenging long-held assumptions about what, and whose, biology matters. By listening closely to hormonal rhythms that were once dismissed as noise, Emily and her lab at the University of California, Santa Barbara, are ushering in a new era of neuroscience that honors biology’s beautiful mess and champions women’s health.
Emily attended Smith College in Northampton, Massachusetts, which had a growing neuroscience program that offered fertile ground for her blossoming interests. Inspired by her first-year roommate, she enrolled in a neuroscience course taught by Dr. Mary Harrington and quickly caught the “neuroscience bug.” From then on, Emily spent every summer conducting basic human brain imaging research with Dr. Maryjane Wraga, using early functional magnetic resonance imaging (fMRI), a non-invasive technique that tracks localized changes in blood oxygenation as a proxy for neural activity. When neurons fire, nearby blood vessels dilate to deliver more oxygen to the region. fMRI leverages the differing magnetic properties of oxygenated and deoxygenated blood to detect what is known as the BOLD (blood-oxygen-level-dependent) signal. For Emily, fMRI was the perfect tool to peer into the workings of the human brain in action.
Eager to explore the neurochemical mechanisms underlying human brain function, Emily joined Dr. Mark D’Esposito’s lab at the University of California, Berkeley. The D'Esposito lab was interested in the basic functions of dopamine in the brain. Inspired by literature demonstrating that high estradiol (the primary form of estrogen) potentiates dopamine release in rodents, Emily developed a project to explore the hormonal modulation of dopamine systems in humans. Using fMRI in combination with genetic and hormonal assays, she discovered that working memory (the brain’s ability to hold and manipulate information over short periods of time) fluctuates with estradiol levels. This effect differed depending on an individual's baseline dopamine. Women with low baseline dopamine genotypes showed improved working memory when estradiol was high, while those with high baseline dopamine genotypes performed better when estradiol was low. Since Emily’s doctoral research revealed how hormonal states could shape working memory, a core aspect of cognition, she began to wonder how the body’s rippling endocrine rhythms might affect brain organization as a whole.
Emily loved her time in graduate school. During her 5 years at UC Berkeley she felt energized by her research and buoyed by her strong support system of mentors and friends both in and outside of academia. This is also where Emily met her now-husband, a fellow scientist. When it came time for them to find postdoctoral positions, they faced the familiar challenge of the two-body problem. The couple ultimately decided to brave what they hoped would be a temporary long-distance stretch as he settled into his postdoc position at MIT, and she joined the Robert Wood Johnson Foundation Health & Society Scholars postdoctoral program at UCSF. While conducting research with Drs. Elissa Epel and Elizabeth Blackburn on the links between telomere biology and endocrine aging, Emily also engaged in interdisciplinary dialogues with lawyers, historians, physicians, and population health scientists. It was there that Emily began to see her neuroscience research as part of a broader effort to understand how health is shaped across the lifespan. Her time in the program deepened her conviction that science should both generate knowledge and serve society.
That conviction led her next to Harvard Medical School, where she joined the NIH-funded Building Interdisciplinary Research Careers in Women’s Health (BIRCWH) program. This was both a professional and personal step, as she and her partner were now finally living on the same coast. Emily joined a cohort of ten PhDs and ten MDs all united by a shared interest in women’s health. This was a scholarly research environment designed to dismantle silos by bringing together endocrinologists, neuroscientists, and clinicians to tackle the complex realities of women’s health across the lifespan. Within this environment, Emily found what she describes as “a room of one’s own”: research independence, protected time, and a team of visionary mentors and colleagues who supported her growth.
In 2015, Emily and her partner faced a fortunate but challenging career crossroads: an opportunity at an Ivy League institution in New York, or one at the University of California, Santa Barbara. Their decision was guided by a shared belief in “science first, ego last”—the idea that good science can happen anywhere, and that feeling at home in their community mattered just as much as the work itself. For them, it wasn’t just about where they could build strong labs, but also where they could build meaningful lives. UCSB offered all of this, and in the years since joining, it has proven to be fertile ground for both of them in science and life. This shared foundation has recently culminated in their first co-authored publication.
Building on her commitment to understanding the brain’s dialogue with hormones, Emily established the Jacobs lab to move beyond traditional group-average snapshots and to instead embrace a more individualized approach to human neuroscience research. They did this by using dense sampling: imaging participants repeatedly across key hormonal transitions to capture how the same brain responds to dynamic internal environments. Inspired by early efforts like the MyConnectome Project, Emily’s team launched 28andMe, a landmark study that tracked brain scans, blood samples, and mood data across a natural menstrual cycle, and then repeated the protocol after a year of oral contraceptive use. This project, led by PhD student Laura Pritschet, resulted in a rare and intimate window into how the brain slowly pulses with hormonal rhythms, and how those rhythms are reshaped by pharmaceutical intervention. Among their many discoveries, they found that estradiol enhances whole-brain connectivity, while progesterone reduces it. They also discovered that progesterone rhythmically reshapes the medial temporal lobe, including the hippocampus, across the menstrual cycle, and that suppressing progesterone with oral contraceptives abolishes these changes. The Jacobs lab’s work has shown, with striking clarity, that hormone fluctuations shape networks like the default mode system, alter hippocampal morphology, and modulate cognitive performance—not just in women, but across sexes. Projects like 28andHe revealed that testosterone, estradiol, and cortisol follow precise daily rhythms in men as well, and that the brain responds to these pulses in kind, sculpting cortical thickness and subcortical volume in sync with the endocrine tide.
Just as importantly, the data from these dense sampling studies is freely available—extending the reach of this work and inviting the scientific community to explore new questions grounded in rich, open-access datasets. Now, by leading initiatives like the Ann S. Bowers Women’s Brain Health Initiative, Emily is scaling the lab’s work into something even bigger: a shared, open-access neuroimaging database enriched for women’s health phenotypes, designed to seed countless new ideas. Inspired by models like the Human Connectome Project and the UK Biobank, the Bowers WBHI team is building the infrastructure needed for large-scale, high-quality, collaborative science—with women at the center from the start.
With each study, Emily pushes against the idea that hormonal variability is mere noise. Instead, she reframes it as a fundamental biological rhythm worthy of attention. From menstrual cycles to pregnancy, menopause, and circadian rhythms, her lab’s work shines light on the brain as a dynamic endocrine organ, continuously shaped by its internal environment. These transitions are not marginal, they are central to the story of the human brain.
Find out more about Emily and her lab’s research here.
Listen to Meenakshi’s full interview with Emily on March 13, 2025 below!
