Dr. Sepiedeh Keshavarzi
Assistant Professor & Group Leader University of Cambridge
Postdoctoral Researcher Sainsbury Wellcome Centre UCL, London
PhD University of Queensland, Australia
Seven and a half years into her medical education in Iran, Dr. Sepiedeh Keshavarzi decided to change course. After finishing her medical exams and graduating as a medical doctor, a brief foray into clinical research convinced her to take the drastic step of changing careers. Sepiedeh is now an Assistant Professor at the University of Cambridge, where her lab studies the neural circuitry underlying spatial orientation and self-motion perception.
Sepiedeh was originally passionate about math and physics and was considering pursuing a university degree in these subjects. However, she was dissuaded because she was told there were limited career opportunities in these fields. Instead, at the age of 18, she redirected her focus towards a career in medicine – a path that typically entailed seven and a half years of rigorous training in her home country of Iran. As she neared the completion of her medical degree, Sepiedeh became concerned about the potential monotony of a medical career. Although the training process was full of novelty, the prospect of routine practice in medicine left her wanting more. In contrast, research provided an ongoing cycle of discovery and experimentation, an aspect that resonated deeply with her curiosity-driven mindset. Sepiedeh approached a faculty member conducting epilepsy research and decided to join the lab as a visiting researcher after completing her medical degree. In the lab, she started a project studying the neuroprotective effect of calorie restriction in a rat model of epilepsy. Alongside acquiring basic laboratory techniques such as perfusion, animal handling and behavioral assessment, this experience ignited her profound fascination with exploring the intricate mechanisms of brain function. It was this newfound passion that prompted her to forgo her career as a medical doctor and instead enter a PhD program in neuroscience.
For her PhD, Sepiedeh wanted to integrate her original interests in math and physics with her growing passion for neuroscience. Believing that an electrophysiology lab would provide the ideal setting, she sought out the lab of Dr. Pankaj Sah at the University of Queensland in Australia. Sepiedeh describes the beginning of her PhD as somewhat terrifying; transitioning to a new country with limited lab experience was overwhelming. Some of the pressure was relieved as Sepiedeh still had the option of returning to a career in medicine. However, as she delved deeper into her doctoral studies, she became increasingly certain that she had found her true calling in neuroscience.
In the Sah lab, Sepiedeh focused on a project studying the organization of olfactory circuits in the amygdala, characterizing the cell types, circuit connections and electrophysiological signatures contained within this brain region. At the time, the part of the amygdala responsible for processing olfactory stimuli remained largely unexplored. Unlike areas directly implicated in Pavlovian fear conditioning, which garnered significant research attention, this particular region lacked a comprehensive map. Sepiedeh found that distinct types of olfactory information originating from the accessory and main olfactory systems converged onto the same neurons in the amygdala. However, these different types of olfactory input were distinguished by their projection sites along the dendritic tree and exhibited distinct temporal integration properties.
As she was transitioning to a post-doc, concerns about visas and her immigrant status heavily influenced her decision-making regarding her next steps. Sepiedeh decided to extend her stay in Australia to attain permanent residency, and thus face fewer visa challenges in the future. She was offered a temporary post-doc position in the lab of Prof. Greg Stuart at the Australian National University, where she gained experience in in vivo techniques while pursuing permanent post-doctoral positions outside Australia.
For her post-doc, Sepiedeh aimed to transition towards a systems-level approach to study multisensory integration in vivo and during behavior. She had interviews scheduled with two labs in the UK, one in the US, and one in Germany. However, her American visa never arrived, leading to the cancellation of her interview. This made it apparent to Sepiedeh that taking a job in the US would be incredibly challenging. The visa system often creates significant hurdles for individuals attempting to re-enter the US after a temporarily departure; even brief trips for family emergencies or conferences can turn into months-long delays in returning to one’s post-doc position.
Taking this into consideration, Sepiedeh joined Prof. Troy Margrie’s lab in the UK at the Sainsbury Wellcome Centre, UCL. Her postdoctoral work aimed to unravel how the brain combines external and internal sensory signals to track one's own motion. She specifically focused on the role of the vestibular sense, both independently and in conjunction with vision, in the brain's computation of self-motion. To this end, Sepiedeh pioneered a sophisticated two-photon calcium imaging technique that allowed optical recording of cortical neurons during natural vestibular stimulation (whole-body rotation of the mouse). By combining this method with viral tracing, she discovered that mouse visual cortical neurons receive head motion information from the retrosplenial cortex (RSC), a key region in the brain’s navigation system. Building upon these findings, Sepiedeh further developed sophisticated methods that allowed her to uncover the contribution of various sensory/motor signals to head-motion coding in the RSC. She was particularly intrigued by how self-motion signals in freely moving animals relate to those typically recorded under restrained and passive conditions. By recording the spiking activity of the same neurons during passive rotation and free exploration sessions, she established that RSC neurons can reliably track the direction and speed of head turns using vestibular inputs alone. These experiments further revealed that the addition of vision increases the accuracy of this head-motion signal and improves the animal’s perception of self-motion.
As she was nearing the end of her post-doc, Sepiedeh knew she wanted to pursue her own experimental ideas, recognizing that establishing her own lab would offer the optimal avenue to fulfill this aspiration. She obtained an assistant professorship at the University of Cambridge and, with the support of a Wellcome Trust Career Development Award, opened her lab in 2023, where she and her team are studying the organization and function of thalamocortical circuits implicated in spatial orientation. She is also interested in studying how these circuits undergo alterations with aging, which is often marked by a loss of navigational abilities. While the focus has traditionally been on spatial memory loss, Sepiedeh’s interest lies in understanding how the online processing of multimodal sensory information for navigation might be implicated. Although her responsibilities have shifted substantially since assuming a faculty role, she finds immense fulfillment in both teaching and overseeing the lab’s setup. She eagerly anticipates the imminent opening of the behavioral wing of her lab. Once opened, it is likely you’ll be able to find Sepiedeh at the bench, actively engaged in the experiments she has so enthusiastically pursued since she fell in love with neuroscience.
Find out more about Sepiedeh and her lab’s research here.
Listen to Margarida’s full interview with Sepiedeh on November 30, 2023 below!
