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Department of Biology, Neuroscience and Cognitive Science, and the Institute for Systems Research Biology/Psychology Building University of Maryland College Park, MD 20742 E-Mail: avis@isrmail.isr.umd.edu Phone: 301.405.0069 Fax: 301.314.5683 |
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Nervous systems are complex systems of interacting centers of activity. Workers in my laboratory study the organization of complex systems, in general, and the lamprey central pattern generator for locomotion, in particular. We study both the normal and the injured spinal cord. Most neuroscientists choose to study either the behavior of whole animals or isolated pieces of nervous systems. However, the intellectual link between these two groups of scientists is often difficult to make. What is the relationship between the behavior of the organism and its nervous system? Clearly, the nervous system generates the behavior, but how?
My colleagues and I study an isolated piece of the nervous system, but an isolated piece that can perform a "behavior." In particular, we study the isolated spinal cord of a primitive vertebrate, the lamprey. For these studies, we use whole animals and semi-reduced preparations. In this way, we are able to bridge the gap between the parts of the system and the whole animal's behavior. The work is focused on the mechanisms underlying the generation of an organized motor behavior, locomotion.
In addition to the normal animal, we also study the process of regeneration in the lamprey spinal cord. The animal spontaneously regenerates after injury, but the regeneration can be either functional or dysfunctional. We study how the spinal cord is organized under the two sets of conditions in hopes of preventing problematic regeneration in people when regeneration is finally achieved in human spinal cord injury patients.
We use neurophysiology, immunohistochemistry, computational and neuromorphic engineering to disentangle the various threads of the system. People using the diverse experimental methods all interact and inform each other. Thus, we hope to understand a complex behavior in a relatively simple animal, and apply the understanding to a much more complex animal - the human.
In related work, engineers and our group work to develop robotic and engineering solutions to the creation of autonomous legged robots as well as working toward a neuroprosthetic device to aid spinal cord injury patients.
Cohen, A.H., Guan,L., Pate,V., and Kiemel, T. 1999. Temperature can alter the functional outcome of spinal cord regeneration in larval lampreys. "Neuroscience," 90:957-965.
Cymbalyuk, G. S., Patel, R. L. Calabrese, G.N, DeWeerth, S. P., Cohen, A.H. 2000. Modeling Alternation to Synchrony with Inhibitory Coupling: A neuromorphic VLSI Approach. "Neural Comput.," 12:2259-2278.
Guan, L. Kiemel, T., and Cohen, A.H. Impact of movement and movement related feedback on the central pattern generator for locomotion in the lamprey. J. Exp. Biol., 204:2361-2370
Cohen, A. H., and D.L. Boothe (in press) "Sensorimotor interactions: Principles derived from central pattern generators." In Handbook of Brain Theory and Neural Networks, ed. M. Arbib. MIT Press.
M. A. Lewis, Etienne-Cummings, R. Hartmann, M.J., Xu, Z.R., Cohen, A.H. (2003) An in silico central pattern generator: Silicon oscillator, coupling, entrainment, and physical computation. Biocybern. 88:137-151.
Fukuoka, Y., Kimura, H., and Cohen, A.H. (2003) Adaptive dynamic walking of a quadruped robot on irregular terrain based on biological concepts. Int. J. of Robotics Research. 22:187-202.
T. Kiemel, Gormley, K.M., Guan, L., Williams, T.L., and Cohen, A.H. (2003) Estimating the strength and direction of functional coupling in the lamprey spinal cord. J. Comput. Neuro.. 13:233-243.
A. H. Cohen, M. Abdelnabi, B. Bent, C. Coleman, L. Guan, A. Mitra, M. A. Ottinger, and L. Chakrabarti (2005) Changes in distribution of serotonin induced by spinal injury in larval lampreys: evidence from immunohistochemistry and HPLC. J. Neurotrauma, 22:172-88.
The Genome of the Sea Urchin, Strongylocentrotus purpuratus(2006) G. M. Weinstock, R. A. Gibbs, E. Sodergren, E. H. Davidson, R. A. Cameron, The Sea Urchin Genome Sequencing Consortium Science A.H. Cohen, ..., 314: 941-952.
D. L. Boothe, Cohen, A. H., Troyer, T. W. (2006) Temporalp pcorrelations in stochastic models of double bursting during simulated plocomotion. J. Neurophysiol. 95: 1556-1570.
Vogelstein, Etienne-Cummings, R.J, Thakor, N.V. and Cohen, A.H. (2006) Phase Dependent Effects of Spinal Cord Stimulation on Locomotor Activity, IEEE Trans Neural Syst Rehabil Eng. 14:257-65.
Hibino, T., Loza-Coll, M., Messier, C., Majeske, A.J., Cohen, A.H., David P. Terwilliger, D.P., Buckley, K.M., Brockton, V., Nair, S.V. Berney, K., Fugmannf, S.D., Anderson, M.K., Pancer, Z., Cameron, R. A., Smith, L.C., Rast,J.P. (2006) The immune gene repertoire encoded in the purple sea urchin genome. Developmental Biology 300:349.
R. J. Vogelstein, F. Tenore, R. Etienne-Cummings, M. A. Lewis, A. H. Cohen (2006) Dynamic control of the central pattern generator for locomotion, Biol. Cyber. 95:555-566.
H. Kimura, Y. Fukuoka and A. H. Cohen, (2006) Adaptive Dynamic Walking of a Quadruped Robot on Natural Ground Based on Biological Concepts, Int. J. of Robotics Research, 26:475-490.
S. Gelman, A. Ayali, E. D. Tytell, A. H. Cohen (2007) Larval lampreys possess a functional lateral line system. J. Comp. Physiol. A.193(2): 271-7.
H. Kimura, Y. Fukuoka and A. H. Cohen (2007) Biologically Inspired Adaptive Walking of a Quadruped Robot, Philosophical Transactions of the Royal Society A, Vol.365, No.1850, pp.153-170
A.H. Cohen,"Growing
Up Female", an Autobiography published in the "Neuroethology Newsletter."
Zurich power point presentation: 10/02 zurich02.ppt
Biosciences Review Day: biosciences_review_02.pdf
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