Yosif (Joe) Zaki, PhD
2026 Leon Levy Scholar in Neuroscience
New York University
Sub-disciplinary Category
Systems Neuroscience
Previous Positions
- BS, Northeastern University
- PhD, Icahn School of Medicine at Mount Sinai (Dr. Denise Cai)
Bio
Dr. Yosif (Joe) Zaki completed his BS at Northeastern University, during which he worked with Dr. Sandeep Robert Datta, Dr. Leon Reijmers, and Dr. Steve Ramirez. He then completed his PhD at Icahn School of Medicine at Mount Sinai with Dr. Denise Cai, where he studied how periods of rest after learning promote the integration of recently formed memories with memories from days past. Dr. Zaki’s PhD work on how sleep and wake states differentially support memory processes ultimately enkindled his interest in investigating the rich spatiotemporal structure of sleep in the pursuit of understanding how sleep supports cognitive function. Dr. Zaki is currently conducting his postdoctoral research at NYU with Dr. André Fenton. As a Leon Levy scholar, he will be investigating the spatiotemporal structure of local sleep.
Research Summary
Mapping the spatiotemporal structure of sleep across the mouse brain, and to test whether and how this structure is modified by experience and neuronal activity while awake.
Technical Overview
Sleep has historically been viewed as a globally uniform state—when an animal is in a state of sleep, the entire brain is in the same state. However, recent studies have discovered evidence for local sleep during which specific brain areas display electrophysiological signatures of sleep independently of the rest of the brain. Evolution has produced remarkable diversity of sleep structure across the animal kingdom, including species that sleep with only one hemisphere of their brain at a time (e.g., dolphins), species that switch between this “unihemispheric” sleep and bihemispheric sleep in an environmental-dependent manner (e.g., seals, penguins, certain birds), and species that have subtler forms of local sleep where specific regions of the brain deviate from an otherwise globally uniform state (e.g., rodents). These observations of local sleep disrupt the notion that sleep is invariably a brain-wide state. Dr. Zaki seeks to investigate the spatiotemporal structure of local sleep across the mouse brain, and to test whether and how experience and neuronal activity during wake periods alter the structure of subsequent sleep. Dr. Zaki is employing state-of-the-art electrophysiological recording tools, engineering solutions to record electrophysiology broadly across the mouse brain, and combining these electrophysiology tools with calcium imaging, chemogenetics, optogenetics, and behavioral assays in freely moving mice to observe and perturb neuronal dynamics to investigate how sleep is structured in space and time across the mouse brain.
Learn about the The Leon Levy Scholarships in Neuroscience.