The taste system develops over a prolonged period and is particularly malleable (i.e., plastic) during development. Although much is known about plasticity in other sensory systems, there is only rudimentary information about plasticity in the taste system. The overall goal of this proposal is to delineate specific morphological and functional changes to the taste system that occur after peripheral neural injury during development. The projects in this proposal build upon our recent work that describes profound alterations in peripheral and central morphology of the taste system after transection in neonatal rats of the nerves that innervate the tongue. Experiments in Aim 1 will track in vivo, degenerative and regenerative changes to the morphology of fungiform papillae after neonatal chorda tympani or lingual nerve transection. In addition, the source and pattern of the few taste buds that remain will be determined.
Aim 2 will build upon our recent finding that the nerve that innervates palatal taste receptors (the greater superficial petrosal nerve) undergoes reorganization and expansion of its central terminal processes after neonatal transection of the chorda tympani nerve. Through the use of tract tracing techniques, experiments will determine the degree to which the modified greater superficial petrosal nerve invades regions of the nucleus of the solitary tract already occupied by the glossopharyngeal nerve.
Aim 3 will examine the structural and functional reorganization of individual neurons of the greater superficial petrosal and the chorda tympani after neonatal chorda tympani transection.
Aim 4 will determine morphological changes that occur after neonatal chords tympani transection to second-order neurons that reside in the gustatory zone of the nucleus of the solitary tract. Proposed studies will provide new information about: 1) the ability of fungiform and filiform papillae to switch phenotypes established during development, 2) the stability of the relationship between taste bud size and number of innervating neurons following severe disruption of that innervation, 3) central gustatory reorganization as it relates to interactions between different populations of afferent neurons, 4) the dynamic relationship between the structure and function of individual gustatory neurons following central reorganization, and 5) morphological changes that occur to central neurons that receive innervation from reorganized afferents. Thus, these studies will contribute not only to an understanding of taste stem plasticity, but also to an understanding of the development of nerve/target interactions.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC004846-03
Application #
6516289
Study Section
Integrative, Functional and Cognitive Neuroscience 8 (IFCN)
Program Officer
Davis, Barry
Project Start
2001-05-01
Project End
2006-04-30
Budget Start
2002-05-01
Budget End
2003-04-30
Support Year
3
Fiscal Year
2002
Total Cost
$236,835
Indirect Cost
Name
University of Nebraska Omaha
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
190827162
City
Omaha
State
NE
Country
United States
Zip Code
68182
Riquier, Andrew J; Sollars, Suzanne I (2017) Microglia density decreases in the rat rostral nucleus of the solitary tract across development and increases in an age-dependent manner following denervation. Neuroscience 355:36-48
Omelian, Jacquelyn M; Berry, Marissa J; Gomez, Adam M et al. (2016) Developmental time course of peripheral cross-modal sensory interaction of the trigeminal and gustatory systems. Dev Neurobiol 76:626-41
Omelian, Jacquelyn M; Samson, Kaeli K; Sollars, Suzanne I (2016) Chronic Oral Capsaicin Exposure During Development Leads to Adult Rats with Reduced Taste Bud Volumes. Chemosens Percept 9:95-104
Sollars, S I; Walker, B R; Thaw, A K et al. (2006) Age-related decrease of the chorda tympani nerve terminal field in the nucleus of the solitary tract is prevented by dietary sodium restriction during development. Neuroscience 137:1229-36
Sollars, Suzanne I (2005) Chorda tympani nerve transection at different developmental ages produces differential effects on taste bud volume and papillae morphology in the rat. J Neurobiol 64:310-20
Carr, V McM; Sollars, S I; Farbman, A I (2005) Neuronal cell death and population dynamics in the developing rat geniculate ganglion. Neuroscience 134:1301-8
Farbman, Albert I; Guagliardo, Nick; Sollars, Suzanne I et al. (2004) Each sensory nerve arising from the geniculate ganglion expresses a unique fingerprint of neurotrophin and neurotrophin receptor genes. J Neurosci Res 78:659-67
Hendricks, Susan J; Sollars, Suzanne I; Hill, David L (2002) Injury-induced functional plasticity in the peripheral gustatory system. J Neurosci 22:8607-13
Sollars, Suzanne I; Smith, Peter C; Hill, David L (2002) Time course of morphological alterations of fungiform papillae and taste buds following chorda tympani transection in neonatal rats. J Neurobiol 51:223-36