University of Southern California

Segil Lab

USC Stem Cell

Lab Overview

Sensory regeneration and inner ear biology

Hearing loss and balance disorders affect more than half of all adults in the U.S. by the time they reach retirement age. The death of sensory hair cells in the inner ear and their failure to regenerate are the major cause of deafness. The long-term goal of our laboratory is the treatment of deafness through regeneration of these sensory hair cells. Our current research is on the developmental processes that shape the complex structures of the inner ear, in particular, the mechanisms that control cell division and cell fate during embryonic development. We also study the homeostatic mechanisms that allow for the lifelong survival of hair cells, as well as the particular sensitivity of these cells to environmental stress from noise, certain antibiotics and chemotherapy agents, and how this relates to the cell cycle, DNA damage and repair.

Cross-section through postnatal day 1 organ of Corti. A single inner hair cell and three outer hair cells are stained green with antibody to Myosin VIIa; the surrounding supporting cells express the cell cycle inhibitor p27Kip1, which is stained red. (Image courtesy of the Segil Lab)
A merged image of a cochlea stained for BrdU (red), indicating regions of cell division, and p27Kip1 (green) from an E14.5 mouse. (Image by Lee et al.)
A whole cochlea dissected from a postnatal day 1 mouse and stained with antibody to BrdU (red, cell division) and MyosinVIIA (green, hair cells). (Image courtesy of the Segil Lab)
Organ of Corti cultured for 48 hours in the absence and presence of gamma-secretase inhibitor DAPT. Supernumerary hair cell-like cells are present in the right-hand panel. Cells are stained with MyosinVIIA (red), and harbor an Atoh1-GFP transgene, which is normally expressed in differentiating hair cells. (Image courtesy of the Segil Lab)
Cultured P1 mouse organ of Corti in the absence (left) and presence (right) of the gamma-secretase inhibitor DAPT for zero, 24 and 48 hours (top to bottom). (Image courtesy of the Segil Lab)