Dr. Jennifer Resnik
Assistant Professor Ben-Gurion University
Postdoctoral fellow Massachusetts Eye and Ear Infirmary, Harvard Medical School
PhD Weizmann Institute of Science
Dr. Jennifer Resnik’s early scientific work was in immunology, but she realized that this area of research was not the right fit for her. After spending two years researching white blood cells for her master’s degree at the Weizmann Institute of Science in Rehovot, Israel, Jennifer sought a more tangible connection to her research. She desired to feel the science: to hear cells spike with electrophysiology, see cells illuminated with imaging, and observe real-time behavior. This led her to find a home in the field of neuroscience. Now, as an assistant professor at Ben-Gurion University, she studies the connection between sound and perception, how perception of sounds can adapt based on experience, and how this change can influence behavior. Her story demonstrates how embracing change and trusting your intuition can lead to a fulfilling and impactful career in science.
Jennifer’s pursuit of feeling the science led her to cross paths with Dr. Rony Paz, a new PI at the Weizmann Institute, whose research on the neuroscience of learning and memory in humans and non-human primates sparked her curiosity. Despite having no formal background in neuroscience, she was drawn to the Paz lab’s research questions, approach, mentor, and environment. Jennifer trusted her instincts and committed to pursuing her PhD in the lab, where she went on to produce a substantial body of research on how fears are learned and generalized.
When confronted with a potential threat, animals refer to their past experiences with similar threats (fear memories) to select a defensive response. This process is referred to as fear generalization. To study this, Jennifer used fear conditioning, which is a classic behavioral neuroscience paradigm where a subject is trained to associate a conditioned stimulus (such as a tone) with something that induces fear (such as an electric shock). In fear conditioning, quickly recognizing and responding to potential threats helps individuals avoid dangerous situations. However, sometimes this heightened threat perception can extend to harmless stimuli. For example, a veteran with PTSD might react with panic to the sound of fireworks because it resembles gunfire. While this reaction was protective in combat, it becomes disruptive in everyday, safe environments. Through her research in both humans and non-human primates, Jennifer observed a broadening of fear generalization after experience with an aversive auditory stimulus. This was due to changes in tuning properties of amygdala neurons that receive input from the auditory cortex. Her findings suggest that even small changes in amygdala activity or in its inputs from the auditory cortex can result in exaggerated fear responses to a broader range of stimuli, as seen in PTSD.
Jennifer came away from her PhD curious about the flexibility of the brain’s auditory system, which led her to Dr. Dan Polley’s lab at Harvard. Moving to a different country and adapting to using mice, a new model organism for Jennifer, presented a unique challenge. However, Jennifer was eager for a change that she foresaw as opening more avenues for her future research. In the Polley lab, Jennifer made major discoveries related to compensatory plasticity in the auditory system. She investigated how auditory cortex activity changes when it receives less input due to auditory nerve damage. After observing hyperactivity in the auditory cortex of mice who recovered cortical sound processing after auditory nerve damage, Jennifer hypothesized that neural inhibition might be reduced to facilitate recovery. Using a combination of in vivo electrophysiology and optogenetics in the mouse auditory cortex, Jennifer identified that compensation for hearing loss was due to changes to the strength of cortical inhibition from parvalbumin expressing neurons. Her findings highlighted the brain's remarkable ability to compensate for significant damage.
In the latter half of her postdoc, Jennifer shifted her focus to explore the effect of the environment on auditory processing. Similar to the cocktail party problem, Jennifer investigated how mice with auditory nerve damage can isolate and attend to relevant acoustic stimuli within a noisy environment. She found that although mice with severe hearing loss can detect sounds in silence, they struggle in more challenging auditory contexts (such as picking out a person’s voice in a crowded room, for humans). Using two-photon calcium imaging, Jennifer observed that auditory nerve damage triggers a cascade of compensatory processes, including hyperactivity of excitatory putative pyramidal neurons and hypoactivity of inhibitory parvalbumin neurons. While these mice could restore their hearing enough to detect sounds in silence, the shift in excitatory-inhibitory balance disrupted the normal processes needed to allow them to adapt to continuous background noise.
As she considered her next steps, Jennifer became increasingly interested in combining her expertise from her PhD and postdoc to investigate how different internal states, such as stress, modulate auditory processing. Jennifer returned to Israel where she established her own lab in the Life Sciences department at Ben-Gurion University. Her lab’s research focus continues to evolve as she investigates how different internal states impact auditory processing and perception. She is now also collaborating with the Ben-Gurion University Autism Research Center to uncover how sound hypersensitivity neurobiologically manifests in different mouse models of autism.
During her career Jennifer received advice that helped her reach this point: perfection can often stand in the way of progress, and sometimes good is good enough. She also recognizes that rejection and negative results are unavoidable in this career path. Jennifer has now learned to celebrate her successes, find joy in the process of doing science, and be resilient in the face of rejection. “Science isn’t something you can do alone,” she reflects. Strengthened by supportive mentors and peers, she always managed to get back up again after things didn’t go according to plan. Jennifer makes sure to instill these principles in her trainees today, focusing on fostering a lab environment that prioritizes collaboration and mutual support.
Through her work on fear generalization, auditory plasticity, and the brain’s remarkable ability to compensate for sensory loss, Jennifer has already contributed significantly to our understanding of how the brain processes sound. Her path demonstrates that trusting your instincts and following your curiosities, even when venturing into unfamiliar territory, can lead to a fulfilling career and impactful scientific discoveries. Jennifer’s drive to feel the science that once drew her to neuroscience still remains at the heart of her work, where the hands-on experience of discovery continues to inspire her as she explores new frontiers.
Find out more about Jennifer and her lab’s research here.
Listen to Meenakshi’s full interview with Jennifer on May 29, 2024 below!
