My proposed project will examine the influence of the descending monoaminergic systems on the movement related receptive fields of spinal interneurons. The overall hypothesis is that the monoamines inhibit divergent sensory input to various spinal interneurons. These interneurons, which are interposed in various reflex pathways, thus have relatively narrow receptive fields. When monoaminergic control to these interneurons is disrupted, such as in spinal cord injury, previously inhibited sources of movement related sensory input are released, exerting uncoordinated facilitation or inhibition of the interneuron. Briefly, I plan to test this hypothesis by performing extracellular recordings of various classes of interneurons utilizing a computer controlled robotic arm that can impose passive movements in three dimensions. I will examine the movement related receptive field size of interneurons before and after varying the monoaminergic input. I will also identify the specific monoaminergic receptor sub-types involved and determine if the neurotransmitter glutamate, which can have similar effects on neurons as the monoamines, works with the monoamines in regulating movement related receptive fields of spinal interneurons. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS048757-03
Application #
7161700
Study Section
Special Emphasis Panel (ZRG1-F02B (20))
Program Officer
Chen, Daofen
Project Start
2004-12-01
Project End
2007-10-31
Budget Start
2006-12-01
Budget End
2007-10-31
Support Year
3
Fiscal Year
2007
Total Cost
$24,129
Indirect Cost
Name
Northwestern University at Chicago
Department
Physiology
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Hyngstrom, Allison; Johnson, Michael; Schuster, Jenna et al. (2008) Movement-related receptive fields of spinal motoneurones with active dendrites. J Physiol 586:1581-93
Hyngstrom, Allison S; Johnson, Michael D; Heckman, C J (2008) Summation of excitatory and inhibitory synaptic inputs by motoneurons with highly active dendrites. J Neurophysiol 99:1643-52
Hyngstrom, Allison S; Johnson, Michael D; Miller, Jack F et al. (2007) Intrinsic electrical properties of spinal motoneurons vary with joint angle. Nat Neurosci 10:363-9