The purpose of the proposed research is to examine the role of specific visual pathways in the recovery of vestibulo-ocular and vestibular neuronal responsiveness following unilateral labyrinth lesions. We will test hypotheses concerning the influence of different inputs to the brainstem and cerebellum that may provide visual signals that promote the development of and are necessary for the maintenance of vestibular compensation. Neurons in the vestibular nuclear complex and prepositus nucleus will be assessed for their responses to linear and angular head acceleration, for visual sensitivity and for oculomotor-related activity, in trained primates, prior to and during recovery from unilateral labyrinthectomy. Those data will be compared with that obtained from additional animals in which hemilabyrinthecomy is preceded by lesions of one of two structures involved in the transmission of signals relayed from visual motion processing areas in the cortex. We hypothesize that lesions of the nucleus of the optic tract, which are known to impair optokinetic responses, will also result in deficits in the recovery of vestibulo-ocular responses to horizontal head acceleration. We will evaluate, in additional animals, another pathway that has been implicated in the early component of optokinetic and smooth pursuit eye movements, the dorsal lateral pontine nucleus, which provides visual inputs to a portion of the vestibulo- cerebellum. Vestibulo-ocular, optokinetic and vestibular neuronal responses will be assessed. The findings of the proposed studies combined with our previous results on the response characteristic of neurons in each visual pathway will provide insights as to the type of visual stimuli that are implicated in the development and maintenance of vestibular compensation. This would in turn suggest strategies for new therapies that could be used in the rehabilitation of patients following labyrinthine injury.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC002726-02
Application #
2414664
Study Section
Hearing Research Study Section (HAR)
Project Start
1996-05-01
Project End
2001-04-30
Budget Start
1997-05-01
Budget End
1998-04-30
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
041367053
City
Galveston
State
TX
Country
United States
Zip Code
77555
McCarthy, Jillian H; Hogan, Tiffany P; Catts, Hugh W (2012) Is weak oral language associated with poor spelling in school-age children with specific language impairment, dyslexia or both? Clin Linguist Phon 26:791-805
Hogan, Tiffany P; Bowles, Ryan P; Catts, Hugh W et al. (2011) The influence of neighborhood density and word frequency on phoneme awareness in 2nd and 4th grades. J Commun Disord 44:49-58
Adlof, Suzanne M; Catts, Hugh W; Lee, Jaehoon (2010) Kindergarten predictors of second versus eighth grade reading comprehension impairments. J Learn Disabil 43:332-45
Catts, Hugh W; Bridges, Mindy Sittner; Little, Todd D et al. (2008) Reading achievement growth in children with language impairments. J Speech Lang Hear Res 51:1569-79
Catts, Hugh W; Adlof, Suzanne M; Weismer, Susan Ellis (2006) Language deficits in poor comprehenders: a case for the simple view of reading. J Speech Lang Hear Res 49:278-93
Finestack, Lizbeth H; Fey, Marc E; Catts, Hugh W (2006) Pro-nominal reference skills of second and fourth grade children with language impairment. J Commun Disord 39:232-48
Catts, Hugh W; Adlof, Suzanne M; Hogan, Tiffany P et al. (2005) Are specific language impairment and dyslexia distinct disorders? J Speech Lang Hear Res 48:1378-96
Stewart, C Matthew; Mustari, Michael J; Perachio, Adrian A (2005) Visual-vestibular interactions during vestibular compensation: role of the pretectal not in horizontal VOR recovery after hemilabyrinthectomy in rhesus monkey. J Neurophysiol 94:2653-66
Hogan, Tiffany P; Catts, Hugh W; Little, Todd D (2005) The relationship between phonological awareness and reading: implications for the assessment of phonological awareness. Lang Speech Hear Serv Sch 36:285-93
Catts, Hugh W; Hogan, Tiffany P; Fey, Marc E (2003) Subgrouping poor readers on the basis of individual differences in reading-related abilities. J Learn Disabil 36:151-64

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