Interim Report

Team Number: 070
School Name: Las Cruces High School
Area of Science: Computer Science
Project Title: A Simulation of Neural Impulses
Project Abstract: http://mode.lanl.k12.nm.us/97.98/abstracts/070.html
Interim Report: http://mode.lanl.k12.nm.us/97.98/interims/070.html
Final Report: http://mode.lanl.k12.nm.us/97.98/finalreports/070/finalreport.html

The goal of our project is to accurately simulate nerve impulses in common neurons. By simulating the neurons we hope to better understand neural activity and aid in the invention of devises that simulate nerve impulses. Although there are four classes of neurons, all neurons have five common components including the cell body, the dendrites, the axon, the axon hillock, and the synapse. The cell body contains the nucleus and much of the metabolic machinery of the cell and can vary in size and shape. The dendrites are usually numerous, short, threadlike cytoplasmic extensions that receive stimuli from other cells. The axon is a long process that is capable of rapidly conducting an electrochemical signal, the nerve impulse, over great distances, reaching up to 2 meters in humans. Axons are also known as nerve fibers. The axon hillock is the sight where the axon is joined to the cell body and is where the electrical firing known as action potential usually occurs. Finally, the synapses are the junctions formed with other nerve cells where the presynaptic terminal of one cell comes into contact with the postsynaptic membrane of another. One of the fundamental activities that we must take into consideration when simulating a nerve impulse is the electrical propagation of the impulse along neural network. Sodium, Na-, and potassium, K+ ions play a key role in maintaining the nerve impulse. Nerve cells maintain a gradient in both sodium and potassium. The sodium-potassium pump keeps a high concentration of potassium inside the cell and a low concentration of sodium inside the cell. As a nerve impulse moves along a neuron, sodium rushes into the cell and potassium rushes out. This depolarizes the next adjacent area of the membrane, opening Na- ion channels to open, allowing the process to be repeated.

In order to accurately simulate nerve impulses we will create a computer model containing only as many of the components of actual neurons as are required. In our research we have discovered a compartmental model that breaks neurons into compartments based on function. A problem with some of the current models, is that they do not take into consideration the length of time it takes a neuron to regain its normal chemical gradients so it can successfully conduct another nerve impulse. We intend to break the problem into small parts that become increasingly detailed and create a simpler model that yields comparable accuracy. Due to the large scale of neural interaction the use of a supercomputer will be necessary. We are currently working on determining what details of a neuron we must accounted for in our simulation. We plan to build our program from a very simple neural model adding details until have created a sufficiently accurate model. Using this method we can solve problems as they arise and will have a completed project at each successive revision of the neural model. The program will be written in C and will produce text output that will be displayed graphically using AVS (an advanced visualization program).

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New Mexico High School Supercomputing Challenge