The long-term goal of this research is to understand the basic computational and control principles which the central nervous system uses to generate functional behavior. Some fundamental principles are implicit in the interaction of the central controller with its peripheral effectors, most importantly muscles. The motor commands of the nervous system and the peripheral response characteristics of the neuromuscular system must be mutually matched for optimal performance. In many systems this matching is accomplished by peripheral modulation which dynamically tunes the properties of the muscle so as to enable it to perform the behavior being commanded by the nervous system. But, although set up as part of the behavior, the modulation generally has much slower dynamics than those of the behavior. In effect, the modulatory state represents a memory, maintained peripherally in the muscle, of past behavior. This memory then prepares the muscle to perform future behavior. It facilitates performance especially of the same kind of behavior as in the past, but may complicate performance if the nervous system commands a different behavior without its presence into account. This peripheral memory and its consequences for control of motor performance and behavior by the nervous system will be studied in a well known, experimentally advantageous model neuromuscular system. The system participates in several behaviors and exhibits a rich variety of neuromuscular modulation on a wide range of time scales. Preliminary studies demonstrate prominent peripheral memory in the system. A strategy combining experiments with mathematical modeling will be used to address the following questions: What motor commands does the nervous system send in the different behaviors? What corresponding modulation occurs? How do the commands and modulation interact to produce functional movement? How does the functional movement change when on the one hand the motor commands, and on the other hand the modulation, are altered? Altogether, this work will test a two-part hypothesis, reflecting the mutual interdependence of controller and effector: that the peripheral memory is required for smooth, efficient integration of successive cycles of a behavior and even for transitions from one behavior to another; but that, at the same time, its existence requires modification of the commands sent by the central nervous system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS041497-01
Application #
6321951
Study Section
Integrative, Functional and Cognitive Neuroscience 8 (IFCN)
Program Officer
Heetderks, William J
Project Start
2001-06-15
Project End
2005-05-31
Budget Start
2001-06-15
Budget End
2002-05-31
Support Year
1
Fiscal Year
2001
Total Cost
$304,250
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Physiology
Type
Schools of Medicine
DUNS #
114400633
City
New York
State
NY
Country
United States
Zip Code
10029
Brezina, Vladimir (2010) Beyond the wiring diagram: signalling through complex neuromodulator networks. Philos Trans R Soc Lond B Biol Sci 365:2363-74
Stern, Estee; GarcĂ­a-Crescioni, Keyla; Miller, Mark W et al. (2009) A method for decoding the neurophysiological spike-response transform. J Neurosci Methods 184:337-56
Proekt, Alex; Wong, Jane; Zhurov, Yuriy et al. (2008) Predicting adaptive behavior in the environment from central nervous system dynamics. PLoS One 3:e3678
Nadim, Farzan; Brezina, Vladimir; Destexhe, Alain et al. (2008) State dependence of network output: modeling and experiments. J Neurosci 28:11806-13
Stern, Estee; Fort, Timothy J; Miller, Mark W et al. (2007) Decoding modulation of the neuromuscular transform. Neurocomputing 70:1753-1758
Brezina, Vladimir (2007) Functional penetration of variability of motor neuron spike timing through a modulated neuromuscular system. Neurocomputing 70:1863-1869
Zhurov, Yuriy; Brezina, Vladimir (2006) Variability of motor neuron spike timing maintains and shapes contractions of the accessory radula closer muscle of Aplysia. J Neurosci 26:7056-70
Lum, Cecilia S; Zhurov, Yuriy; Cropper, Elizabeth C et al. (2005) Variability of swallowing performance in intact, freely feeding aplysia. J Neurophysiol 94:2427-46
Zhurov, Yuriy; Brezina, Vladimir (2005) Temperature compensation of neuromuscular modulation in aplysia. J Neurophysiol 94:3259-77
Zhurov, Yuriy; Weiss, Klaudiusz R; Brezina, Vladimir (2005) Tight or loose coupling between components of the feeding neuromusculature of Aplysia? J Neurophysiol 94:531-49

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