The reticulospinal tracts are a major descending system, but their role in motor control has received limited study. Understanding reticulospinal function is important because when brain injuries affect cortex, extrapyramidal systems like the reticulospinal system may be critical for functional recovery. The present investigations are designed to reveal the function of reticulospinal outputs originating in the pontomedullary reticular formation (PMRF), in nucleus reticularis gigantocellularis and nucleus reticularis pontis caudalis. Experiments for Aim 1 are designed to measure reticulospinal outputs to muscles of the arm and shoulder girdle bilaterally (24 muscles). Understanding how arm muscles are controlled bilaterally by the reticulospinal system will permit understanding of this systems capacity for contribution to functional recovery after stroke. Experiments for Aims 2-3 explore mechanisms for corticospinal and reticulospinal interaction in the control of movement.
Aim 2 uses physiological methods to study corticoreticular coordination through paired stimulus-triggered averaging studies in the cortical motor areas (Ml, SMA, and PMd) and the PMRF. Experiments for Aim 3 will use neuroanatomical methods to reveal the sources of corticospinal cells with collaterals to reticulospinal cells and to determine the strengths of projections from SMA, PM, and Ml to the reticulospinal system. Combined, Aims 2 and 3 examine substrates for coordination of corticospinal and reticulospinal control of movement. Experiments for Aim 4 will test for kinematic and kinetic coding in the activity of PMRF neurons, testing for directional tuning and coding of force. Together, these experiments will measure the outputs and functions of the reticulospinal system along with the relevant sources of input from cortical projections for the preparation and performance of reaching. Much of the focus will be on coordination of bilateral arm movements, which is proposed to be a key function of the reticulospinal system. Bilateral coordination of arm movements is important for functional activities, such as wheelchair mobility, walking with assistive devices, and bed mobility, which are central to neurological rehabilitation after stroke. Thus, the proposed studies will significantly extend our understanding of a critical but poorly understood part of the motor control system of the brain. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
2R01NS037822-05A2
Application #
6927620
Study Section
Sensorimotor Integration Study Section (SMI)
Program Officer
Chen, Daofen
Project Start
1999-07-30
Project End
2009-01-31
Budget Start
2005-02-15
Budget End
2006-01-31
Support Year
5
Fiscal Year
2005
Total Cost
$326,043
Indirect Cost
Name
Ohio State University
Department
Other Health Professions
Type
Schools of Medicine
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Ortiz-Rosario, Alexis; Adeli, Hojjat; Buford, John A (2017) MUSIC-Expected maximization gaussian mixture methodology for clustering and detection of task-related neuronal firing rates. Behav Brain Res 317:226-236
Hirschauer, Thomas J; Buford, John A (2015) Bilateral force transients in the upper limbs evoked by single-pulse microstimulation in the pontomedullary reticular formation. J Neurophysiol 113:2592-604
Ortiz-Rosario, Alexis; Adeli, Hojjat; Buford, John A (2015) Wavelet methodology to improve single unit isolation in primary motor cortex cells. J Neurosci Methods 246:106-18
Ortiz-Rosario, Alexis; Berrios-Torres, Ioannisely; Adeli, Hojjat et al. (2014) Combined corticospinal and reticulospinal effects on upper limb muscles. Neurosci Lett 561:30-4
Montgomery, Lynnette R; Herbert, Wendy J; Buford, John A (2013) Recruitment of ipsilateral and contralateral upper limb muscles following stimulation of the cortical motor areas in the monkey. Exp Brain Res 230:153-64
Herbert, Wendy J; Davidson, Adam G; Buford, John A (2010) Measuring the motor output of the pontomedullary reticular formation in the monkey: do stimulus-triggered averaging and stimulus trains produce comparable results in the upper limbs? Exp Brain Res 203:271-83
Sakai, S T; Davidson, A G; Buford, J A (2009) Reticulospinal neurons in the pontomedullary reticular formation of the monkey (Macaca fascicularis). Neuroscience 163:1158-70
Davidson, Adam G; Schieber, Marc H; Buford, John A (2007) Bilateral spike-triggered average effects in arm and shoulder muscles from the monkey pontomedullary reticular formation. J Neurosci 27:8053-8
Davidson, Adam G; Buford, John A (2006) Bilateral actions of the reticulospinal tract on arm and shoulder muscles in the monkey: stimulus triggered averaging. Exp Brain Res 173:25-39
Davidson, Adam G; Buford, John A (2004) Motor outputs from the primate reticular formation to shoulder muscles as revealed by stimulus-triggered averaging. J Neurophysiol 92:83-95

Showing the most recent 10 out of 11 publications