Cochlear Stress Responses - Adams Laboratory
Much of the work in the Adams laboratory deals with non-sensory cells of the cochlea. This is not because sensory cells are thought to be uninteresting or even well understood, but rather because non-sensory cells are clearly essential for cochlear function and because there is growing evidence that they are often affected earlier and more severely by cochlear stresses than are sensory cells. This suggests that many poorly understood cochlear pathologies may be caused by insults that begin by compromising non-sensory cells. It is therefore reasonable to expect that the study of stress responses in non-sensory cells will lead to a better appreciation of the causes of cochlear disorders and this will provide insight into better prevention and treatment of these disorders.
Somewhat more than half the cells in the inner ear are connective tissue cells and most of these are present in the spiral ligament. The description of the distribution of the gap junction protein connexin 26 in epithelial and connective tissue cells (Kikuchi et al.), together with much previous work from other labs, convinced most cochlear researchers that K+ ions re-circulate from the perilymphatic space to the interior of the stria vascularis via gap junctions among and between fibrocytes of the spiral ligament. There is growing evidence, however, that cells within the spiral ligament have additional functions other than acting as mere conduits of K+ ions. Experiments are underway which are designed to help determine these functions.
A primary concern in this lab is with seeking ways to complement the work of the Otopathology Laboratory on basic and applied research issues. This includes efforts as disparate as optimizing tissue processing protocols and studying poorly understood cochlear cells whose malfunction may account for hearing loss. The applied research includes ongoing efforts to develop and improve techniques for processing and analyzing both newly acquired and archived temporal bones of patients who had inner ear disorders during their lives. Analyses and interpretations of these pathological specimens are aided by insights provided by results of the basic research program.
NF kappaB reporter mouse showing yellowish green type II fibrocytes that have activated NF kappaB in response to a systemic injection of the inflammatory agent LPS. The stria vascularis and type II fibrocyte regions (red) are stained for ATPase.
Joe C. Adams, Ph.D.
243 Charles Street
Boston, MA 02114