Although the vestibular system has exquisite sensitivity in signaling head movement in space, additional information about the orientation of the body in space is needed for the control of balance. Vestibular afferent information is interpreted and shaped in the context of proprioceptive and visual information. To achieve stable balance, it is likely that integration of vestibular and leg proprioceptive afferent signalsis critical, since the legs typically serve as the sole interface with the ground and limb position shapes vestibulospinal responses. However, virtually nothing is known about how limb afferent signals are integrated with vestibular afferent signals in central vestibular pathways. The primary goal of this application is to determine the influence of somatosensory limb inputs on the activity of vestibular nucleus (VN) neurons.
Three specific aims are proposed. In the first specific aim, we will characterize how hindlimb movements affect the responses of VN neurons to rotations of the head that activate labyrinthine receptors. We will additionally determine which subclass of VN neurons is sensitive to hindlimb movement. In the second specific aim, we will determine whether VN neurons differentiate between self-generated hindlimb movement and externally applied movement. In the third specific aim, we will determine whether hindlimb movement signals to VN neurons are amplified following loss of labyrinthine inputs, and substitute for the lost vestibular signals. These experiments are expected to advance understanding regarding the processing of limb somatosensory inputs in central vestibular pathways and may ultimately lead to novel therapies for vestibulopathic patients.

Public Health Relevance

The proposed experiments will investigate the contributions of hindlimb proprioceptive signals to balance control through their influences on vestibular nucleus neurons. It is anticipated that the results of these experiments will ultimately suggest novel therapeutic treatment strategies for patients with balance disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08DC013571-03
Application #
9184550
Study Section
Communication Disorders Review Committee (CDRC)
Program Officer
Rivera-Rentas, Alberto L
Project Start
2014-12-01
Project End
2019-11-30
Budget Start
2016-12-01
Budget End
2017-11-30
Support Year
3
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
McCall, Andrew A; Miller, Derek M; Yates, Bill J (2017) Descending Influences on Vestibulospinal and Vestibulosympathetic Reflexes. Front Neurol 8:112
Miller, Derek M; DeMayo, William M; Bourdages, George H et al. (2017) Neurons in the pontomedullary reticular formation receive converging inputs from the hindlimb and labyrinth. Exp Brain Res 235:1195-1207
McCall, Andrew A; Miller, Derek M; DeMayo, William M et al. (2016) Vestibular nucleus neurons respond to hindlimb movement in the conscious cat. J Neurophysiol 116:1785-1794