Dr. Rocio Servin
Postdoctoral Researcher Scripps Research
PhD in Cellular and Molecular Biology Max Delbrück Center for Molecular Medicine
When Dr. Rocío Servín was a child, her teachers became concerned when she was visibly upset by the fairytale Little Red Riding Hood. But little Rocío did not think the story was too scary—on the contrary, she was upset that the story portrays the wolf as evil, when clearly wolves are incredibly interesting and wonderful creatures! Her reaction was a foreshadowing of the awe-filled scientist she would become. Rocío’s parents are both biologists, and her father did field work with wolves, so Rocío developed an early, voracious curiosity for nature and all its wonders. This inquisitiveness later drove her to forge her own path in science, and today, Rocío is applying for faculty positions. Building off her postdoctoral work in the Patapoutian Lab at Scripps Research, she aims to start a lab that studies the role of the sensory system in gastrointestinal tract function.
When she matriculated at the Universidad Nacional Autónoma de México, Rocío chose to study general biology. While the choice was motivated merely by an instinct that she would enjoy it, Rocío was soon certain that she had made the right decision. As she learned more and more about biology, she felt a whole world opening in front of her—a world she was eager to explore. For her undergraduate thesis project, Rocío researched ion channels in sperm cells. Feeling at home in the lab, she made up her mind that she wanted to have her own research group one day. Working towards that goal, Rocío stayed on in the lab after graduating to do a master’s thesis. She examined the effects of progesterone on intracellular calcium transients in sperm, gaining an appreciation for ion channel biology, which has remained an undercurrent throughout her work.
As she wrapped up her master’s degree, Rocío knew that she wanted to move abroad for her PhD. She was thrilled to be offered an interview at Freie Universität Berlin. Between the adventure of exploring Berlin for the first time and the excitement of the scientific conversations she had with professors there, it was an easy “yes”. She joined Dr. Gary Lewin’s lab at the Max Delbrück Center for Molecular Medicine. For her thesis work, Rocío continued studying ion channels, but this time in chondrocytes—the cells that make cartilage. Using electrophysiology, she tested chondrocyte responses to different types of mechanical stimuli, characterizing these responses and determining which mechanoreceptors were responsible for the resulting currents. This first foray into mechanosensory biology was paradigm-shifting for Rocío. Through her undergraduate and master’s research as well as in classes and textbooks, she had become deeply familiar with ligand-gated ion channels. The idea that mechanoreceptors could be activated by their physical environment rather than by a chemical cue was mind-blowing. The first direct evidence of mechanosensation in chondrocytes, Rocio’s work demonstrated that, while TRPV4 and PIEZO1 channels contribute to the chondrocytes’ response to a disruption to the points of contact between the cell and what it’s attached to, sensation of cell stretch is mediated only by PIEZO1. These results suggest that different mechanical stimuli in the environment can affect chondrocytes in distinct ways via channel selectivity.
As she wrapped up her PhD, Rocío was eager to pursue the next big challenge, and she felt that there was so much more to discover in the realm of mechanosensation. PIEZO1, one of the channels she had studied during her dissertation, had been discovered only two years before she started her PhD, and Rocío wanted to understand what other roles it might play in the body. She thus began a postdoctoral fellowship in the lab that had discovered the PIEZO channels: the Patapoutian lab at Scripps Research in California. While she had become an expert in electrophysiology during her PhD, Rocío wanted to branch out and study mechanosensation at the level of an entire biological system rather than just a single cell type. She chose to explore mechanosensation in the gastrointestinal (GI) tract and discovered that the mechanoreceptor PIEZO2 is required for proper transit of material through the gut. The GI tract is an extremely dynamic system that, in addition to receiving information via nutrients and circulating factors, is innervated by several different types of neurons: those of the enteric nervous system within the intestine, as well as extrinsically from the dorsal root ganglia (DRG) and nodose ganglia. DRG neurons—whose cell bodies are in clusters near the spinal cord—have been shown to mediate interoception (information about the internal state of the body) but largely in the context of pain. On the other hand, the nodose ganglia—whose cell bodies reside near the neck—are widely known to innervate internal organs and mediate their functions. Based on this literature, when Rocío first discovered that knocking out PIEZO2 altered transit time through the gut, she hypothesized that gut mechanotransduction was mediated by the nodose ganglia. After several careful, elegant experiments, however, she proved herself wrong and found that it was the DRG neurons that were regulating gut transit via PIEZO2-mediated sensation. Her study is one of the first to link DRGs to homeostatic function of internal organs.
While her postdoctoral work culminated in an important and exciting finding, the postdoc was not all smooth sailing. About two years in, Rocío began to doubt that she had the necessary skills to become a PI. Because this was a goal she had been chasing since she was an undergraduate, this doubt brought with it a total identity crisis that left Rocío feeling like the long journey might end in failure. It took a couple years, but Rocío experienced immense personal growth during her postdoc, coming not only to believe in her abilities as a scientist, but also to be content with the idea of an alternate career if academia did not work out, reframing it from a “failure” to simply another path. Importantly, she learned to appreciate the skills she has gained during her training and how they could be advantageous across several other careers. Laughing, she relates that she is now almost more afraid of starting her lab than the prospect of not getting the opportunity to do so!
Compounding her crisis of conviction within the lab, Rocío also faced difficulties outside the lab during her postdoc. She found herself overwhelmed by the sudden feeling of culture shock, which came as a huge surprise given the geographical proximity between her postdoc lab in southern California and her home in the north of Mexico. It was perhaps even more unexpected because it was something she had not felt in Germany thousands of miles away. Rocío found that, here in the U.S., she was not just “Rocío”, she was “a Latina”, and people harbored stereotypes and opinions about her based on this cultural identity. While the initial shock has died down, it’s something she still grapples with. She feels that if she does end up leading a lab, she would like to use her position of power to be proactive in helping to ease the experiences of those facing similar race- and ethnicity-based difficulties.
As she navigates the faculty job market, Rocío has put a lot of thought into the scientific questions she would like to answer in her own lab. She feels lucky to have built a solid foundation studying sensory innervation in the gut—there is so much more to uncover in terms of how our nervous system senses and regulates the dynamic environment of the GI tract. Furthermore, while everyone knows from experience that stress or other emotional states can influence gut function, the neural underpinnings of emotion-GI interactions are still unknown. When Rocío starts her lab, I have a gut feeling that she and her team will lead the way in answering these fundamental questions.
Listen to Catie’s full interview with Rocio on November 4th, 2023 below!
