OHSU

Karla S. Kent

Karla S. Kent Karla S. Kent, Ph.D. (1986, Harvard University)


Associate Professor

Research: Hormonal Influences on Neural Development

Steroid hormones exert profound effects on the nervous system, but the mechanisms underlying steroid-induced remodeling of neuronal morphology are incompletely understood. Metamorphosis of the moth, Manduca sexta, provides a dramatic example of hormonally mediated changes associated with remodeling of both the nervous system and the body. The large size of the insect and the simplicity of its nervous system have allowed us to identify individual neurons and manipulate hormone titers to characterize steroid mediated regressive and regenerative changes at the level of dendrites and synaptic terminals. Recently, we have identified molecules that are expressed by motor neurons and their target muscles during metamorphic remodeling. These molecules include adhesion receptors that have been proposed to play important roles in development, regeneration, and learning and memory. Our current work is focused on determining the role of these molecules during neuronal remodeling and identifying the levels at which steroid hormones regulate their expression and localization. These studies will contribute to a more thorough understanding of the multiple effects and mechanisms by which steroids and steroid-like molecules affect the nervous system during development, learning, and regeneration.

Research Support

National Science Foundation
Medical Research Foundation of Oregon

Representative Publications

Knittel LM, Kent KS. Remodeling of an identified motoneuron during metamorphosis: hormonal influences on the growth of dendrites and axon terminals.J Neurobiol. 2005;63(2):106-25.

Knittel LM, Kent KS. Remodeling of an identified motoneuron during metamorphosis: central and peripheral actions of ecdysteroids during regression of dendrites and motor terminals. J Neurobiol. 2002;52(2):99-116.

Knittel LM, Copenhaver PF, Kent KS. Remodeling of motor terminals during metamorphosis of the moth Manduca sexta: expression patterns of two distinct isoforms of Manduca fasciclin II. J Comp Neurol. 2001;434(1):69-85.

Kent KS, Oland LA, Hildebrand JG. Development of the labial pit organ glomerulus in the antennal lobe of the moth Manduca sexta: the role of afferent projections in the formation of identifiable olfactory glomeruli. J Neurobiol. 1999;40(1):28-44.

Kent KS, Fjeld CC, Anderson R. Leg proprioceptors of the tobacco hornworm, Manduca sexta: organization of central projections at larval and adult stages. Microsc Res Tech. 1996 15;35(3):265-84.