DATE: | Tuesday, Jan. 31, 2006 |
TIME: | 2:30 pm |
PLACE: | Council Room (SITE 5-084) |
TITLE: | Chaotic Systems for Brain Modeling |
PRESENTER: | Dragos Calitoiu Carleton University |
ABSTRACT:
Neuromodeling is usually motivated by a desire to better understand
specific neural circuits, particularly those whose failure triggers human
illnesses. Depression, anxiety, schizophrenia, Alzheimer's disease,
memory impairment, paralysis, epilepsy, multiple sclerosis, Parkinson's
disease, etc. are areas in which intense research efforts are being made
so as to better understand and treat these conditions. In this respect,
from a modeling perspective, one hypothesis is that the analysis of the
connections between the neurons is fundamental. Apart from providing a
better understanding of the conditions and symptoms of a disease, such an
analysis also leads to a better understanding of the development and
function of the normal brain. The brain is virtually unique in its
exquisitely complex three dimensional structure. Although the structure
and the functionality of other types of tissues can be explained without a
precise knowledge of their shape and the specific connections of each cell,
this is not easily achieved for the brain. The tools used today to analyze
the shape and structure at the brain^Rs cellular level are scarcely
capable of describing the precise performance of systems consisting of
more than a handful of neurons. One must analyze the shape and connections
of at least thousands, probably millions and perhaps billions of nerve
cells before claiming to fully understand the structures that determine
the behavior of flies, worms, mice, and humans. To the best of our
knowledge, the problem of defining the minimum scale for modeling the
brain (or large sections of the brain) remain unsolved.
In this context, research involving brain modeling has followed two
distinct approaches, namely (a) those which involve a large scale network
of neurons, and (b) those which incorporate a small scale network of
neurons. Each of these models has advantages and disadvantages.
Objectives of our research:
1. We would like to demonstrate that if the brain is modeled as a
large scale network of neurons, where each neuron has a fairly elementary
model, the resulting network can demonstrate chaotic phenomena. In this
regard, we intend to work with a primitive model of the pyramidal neuron
of the piriform cortex.
2. We would like to demonstrate that if portions of the brain are
modeled as small scale networks, the latter again demonstrates chaotic
behavior. In this regard, we shall utilize the Hodgkin-Huxley neuron and a
Bursting neuron to demonstrate that the chaos in the networks of such
neurons can be controlled.
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