Download C Description of Symposium

C Description of Symposium
This description is the basis upon which the program committee will select
proposals. Please describe the symposium in non-technical terms (so that
the committee members with a diverse background can understand the
relevance). Write it like you write the proposal summary of an NSF
proposal. You have to convince the committee that the topic is a)
important b) relevant and c) interesting for more than a few specialists in
the field. Describe the role of each speaker and what she/he will present
and how it complements the other speakers. In other word, we would like
to see an overall plan and coherence between the speakers. Like an NSF
summary, please stay within 1 page.
FORMATION AND CONTROL OF WAVE DYNAMICS IN THE BRAIN
Symposium Chair: S. J. Schiff
During the past several years, there have been substantial developments in our
understanding of neuronal network pattern formation in both theory and
experiment. Spiral waves have been discovered in mammalian brain, as
predicted by theory. Progress in both the theory of controlling wave
synchronization and propagation, as well as experiments confirming propagation
control, have been performed. Lastly, the first intracellular interaction data from
spontaneous seizure formation has revealed the unexpectedly important role that
inhibitory interneurons play in the orchestration of seizures. These findings shed
new light on our understanding of neuronal pattern formation in normal and
disease states.
SPEAKERS:
S. J. Schiff (George Mason University)
W. Troy (University of Pittsburgh)
B. Gluckman (George Mason University)
P. So (George Mason University)
ABSTRACTS:
S. J. Schiff, X. Huang, Q. Yang, H. Ma, J-Y Wu
'Spiral Waves in Mammalian Brain - Experiments'
We report stable rotating spiral waves in mammalian tangential brain slices
visualized by voltage-sensitive dye imaging. Spiral waves occurred
spontaneously and alternated with plane, ring, and irregular waves. Spiral
rotation rates were about 10 turns per second, and the rotation was linked to the
oscillations in a one-cycle-one-rotation manner. A small slowly drifting phase
singularity occurred at the center of the spirals. Such spiral waves may provide a
spatial framework to organize cortical oscillations.
------------------------------W. Troy, C. R. Liang
'Spiral Waves in Brain – Theory'
We investigate wave formation in a two dimensional Wilson-Cowan type model of
neural media. Two dimensional waves that are observed in the model include
rotating spirals, ring shaped plane waves, and periodic waves. All of these have
experimental counterparts recently discovered in the occipital cortex of the rat.
Movies will be shown which compare both model and experimental results.
------------------------------B. Gluckman
'Controlling Wave Propagation in Cortex – Theory and Experiment'
We experimentally confirmed predictions that modulation of neuronal threshold
with electrical fields can speed up, slow down, and even block traveling waves in
neocortical slices. The predictions are based on a Wilson-Cowan type
integrodifferential equation model of propagating neocortical activity. Wave
propagation could be modified quickly and reversibly. To the best of our
knowledge, this is the first example of direct modulation of threshold to control
wave propagation in a neural system.
------------------------------P. So
'Controlling Neuronal Synchronization with Electrical Fields - Theory
Heterogeneous model neurons were synaptically coupled and embedded within
a resistive array, thus allowing the neurons to realistically interact both chemically
and electrically. An applied electric field was found to be effective in controlling
the transition of synchrony between these neurons. A simple phase oscillator
reduction was successful in qualitatively reproducing these results. These
findings suggest a larger scale model in which the effects of electric fields on
seizure activity may be simulated. Predictions on the control of wave propagation
for future experiments are detailed.
D For each invited speaker:
Name: S. J. Schiff
Affiliation: George Mason University
Phone: 703-993-4336
Email: [email protected]
Postal Address: Krasnow Institute, MS 2A1, GMU, Fairfax, VA 22030
Name: W. C. Troy
Affiliation: University of Pittsburgh
Phone: ___________________
Email: [email protected]
Postal Address: University of Pittsburgh, Pittsburgh, PA 15260,
Name: B. J. Gluckman
Affiliation: George Mason University
Phone: 703-993-4384
Email: [email protected]
Postal Address: Krasnow Institute, MS 2A1, GMU, Fairfax, VA 22030
Name: P. So
Affiliation: George Mason University
Phone: 703-993-4377
Email: [email protected]
Postal Address: Krasnow Institute, MS 2A1, GMU, Fairfax, VA 22030
E. Session Chair (this can be you)
It is very important that a session chair is selected at the time of proposal
submission. The session organizer can act as chair. The chair needs to be
absolutely committed to attend the March meeting and chair the session.
The chair needs to be absolutely committed to attend the March meeting
and chair the session. The session chair needs to be available for phone
calls during the sorters meeting December 10-11.
Name: S. J. Schiff
Affiliation: George Mason University
Phone: 703-993-4336
Email: [email protected]
Postal Address: Krasnow Institute, George Mason Univ., Fairfax, VA 22030