BME7900 Seminar: Antonio Fernandez-Ruiz (Cornell)

Novel neural interfaces for large-scale, long-term recordings and manipulation in behaving animals A central challenge in neuroscience is to understand how neuronal activity across brain areas generates complex behaviors. Recent advances in implantable bioelectronics have enabled simultaneous recordings of hundreds of neurons in behaving animals. However, existing neural interfaces often remain bulky, constraining animal behavior, and rigid recording electrodes do not allow recording the same neurons over multiple days due to tissue micromovements, limiting the study of learning and memory mechanisms. In this talk, I will present our recently developed implantable platforms for large-scale, long-term neural recording and manipulation in rodents and other animals. We created parylene-C–based, high-density flexible electrodes using a multilayer design and micro-patterned conducting polymers, achieving a higher density-to-volume ratio than existing silicon probes. These devices allow stably tracking hundreds of the same neurons for months, overcoming the limitations of rigid recording electrodes. We further engineered a wireless neural interface enabling untethered recording and closed-loop modulation in freely behaving small animals. Direct under-chip bonding of flexible probes yielded a compact system weighing under 1.2 g. Integrated onboard sensors captured behaviorally relevant variables, including locomotion, vocalization, and pupil dynamics. An AI-driven embedded signal-processing pipeline detected neural and behavioral biomarkers in real time to trigger targeted interventions. Together, these technologies have enabled us to investigate neural mechanisms of behavior under conditions that were previously inaccessible. Bio: Antonio Fernandez-Ruiz is an associate professor at the Department of Neurobiology and Behavior in Cornell University. He studied physics and biology at the Universities of Sevilla and Madrid, in Spain. He completed his Ph.D. at the University of Madrid, where he developed machine learning methods to study the biophysical basis of brain dynamics. He then moved to New York University to work as a postdoctoral fellow in the laboratory of Gyorgy Buzsaki. His research focused on the neural circuit mechanisms of learning and memory in rodents. His work elucidated how the temporal coordination of excitatory and inhibitory inputs mediates communication between brain areas and supports learning. He developed a novel approach to causally probe the role of specific patterns of neural activity in behavior and used it to demonstrate the key function of neuronal sequence in memory formation. The overarching mission of his lab at Cornell is to understand how neuronal dynamics in distributed brain circuits support complex cognitive functions and how small imbalances can lead to pathological states. His group investigates the algorithmic and mechanistic underpinnings of learning, memory and decision making in health and disease at the computational, circuit, and cellular levels. Work from his laboratory elucidated how cellular heterogeneity and circuit dynamics contribute to the computational capabilities of hippocampal and cortical structures, found novel circuit for the associative and predictive functions of memory and discovered how the temporal organization of brain dynamics in sleep contribute to memory consolidation and integration. They also develop novel technology for a more precise interrogation of neural circuit activity in health and disease. Antonio is a Pew, Klingenstein and Sloan Scholar, and the recipient of the Gruber International Research Award in Neuroscience (SfN), the Blavatnik Award for Young Scientists in the Life Sciences, the Freedman Prize for Exceptional Basic Research (BBRF), the New Innovator Award (NIH) and the MIND Prize (PSF).