Challenge Team Interim Report
Team Number: 054
School Name: Manzano High School, Albuquerque, NM
Area of Science: Medicine
Project Title: The Effects of Ethanol on the Brain
We are interested in modeling how certain chemicals affect the
function and characteristics of the brain. To do this, we are studying the
effects of Ethanol (alcohol) on the brain. By modeling the effects of certain
concentrations of Ethanol on the various areas of the brain, we wish to be
able to show the magnitude of this effect on a normal human brain. This model
will show the probability of receptors that will fire as opposed to receptors
that will not fire due to the effects of Ethanol. In this model, we
will deal with two separate types of neurotransmitters: The Gamma Amino
Butyric Acid, GABA, neurotransmitter, which is a major inhibitory
neurotransmitter in the brain, and the Glutamate neurotransmitter, which is a
major excitatory neurotransmitter in the brain. These two types of
neurotransmitters are affected most by Ethanol, and therefore affect the body
most when one is intoxicated. By mapping out the effects of Ethanol on these
transmitters, and adjusting the figures due to tolerance, we will be able to
display the probable changes that would occur in the brain.
The human body is one of the most complex systems known to man. The nervous network of the human body, which controls all of what occurs in the body, is made of two parts: the central nervous system and the peripheral nervous system. The central nervous system, which includes the brain and the spinal cord, processes and integrates signals received from the peripheral nervous system as well as return signals to it. The peripheral nervous system provides a communication link between the central nervous system and other parts of the body. The basic unit of both parts of the human body's nervous network is a neuron.
The neuron is what is called an excitable cell, which means that the membrane of the neuron is capable of generating and directing an electrical impulse in the form of a temporary reversal of its membrane potential. In the resting state, neurons are electrically negative on the inside with respect to the outside. If a cell reduces its charge beyond a fixed limit, a reversal of polarity occurs. This polarity reversal is known as a spike potential. The spike potential is one of several kinds of active membrane responses involving changes in the electrical properties of membranes and known collectively as action potentials. There are mechanisms for transmitting the action potential from one cell to another that permit nerve cells to communicate with other nerve cells, actuate muscles and other cells, and receive signals from the sense organs.
The main body of the neuron, which contains the nucleus, has many short processes radiating from it, called dendrites. A single longer process, called the axon, also radiates from the main body of the neuron. With most neurons, the impulse originates at the dendrites and travels past the cell body to the tip of the axon, from which it is then passed to the dendrites of another nerve cell or to a muscle cell membrane. The junction between two neurons is called a synapse.
Neurotransmitters enter the neuron and affect the polarity of the cell, affecting the message that the neuron will send out. There are hundreds of neurotransmitters in the brain. The neuron receives these neurotransmitters by way of receptors. Each neuron may have up to 100,000 different types of receptors to receive different neurotransmitters. The two neurotransmitters, Gamma Amino Butyric Acid (GAMA) and Glutamate are affected by alcohol more than the other neurotransmitters in the brain. GAMA is an inhibitory neurotransmitter, which means that it causes the neuron to cease firing signals. Glutamate is an excitatory neurotransmitter, which means it increases the signals that the neuron will fire. GAMA and Glutamate are naturally balanced so that each neuron is not overly inhibited or excited. However, when alcohol is consumed, GAMA production will increase and Glutamate production will decrease. The body will try to rebalance these neurotransmitters again by producing more Glutamate to match the increased GAMA. This is the build up of tolerance. When an alcoholic stops drinking, the body is still producing the extra amount of Glutamate. The alcoholic may then seize because his neurons are unnaturally excited.
The calming and exciting of a cell is a matter of simple chemical
reactions. Each receptor on a neuron is a pore made of proteins . When GAMA
meets the receptor, it causes an increase in the amount of Cl- going into the
cell. This anion makes the neuron resistant to polarization. Glutamate, on
the other hand, causes an increase in Na+ going into the neuron. The cat
causes the neuron to polarize, therefore allowing the cell to send a signal.
METHOD OF SOLUTION:
The basis of our mathematical model is the effect of Ethanol on the GAMA and Glutamate neurotransmitters and how the change in the neurotransmitters will the affect overall neuron activity. The effect can be expressed as a function of the alcohol concentration in the brain. We will express this effect by comparing the normal activity of certain neurons in the brain with the affects of alcohol using probability. The model will show the comparative brain activity with different alcohol concentrations to normal brain activity.
We will use a C++ program to model our project. The basic function of the program will be to analyze input, variable, and constant parameters which affect how GABA and Glutamate are affected by Ethanol and output the results to files for the purposes of viewing them graphically.
After the computer program is completed, the data points from the
output files will be placed into tables and graphed.
So far we have completed the basic research and have the background necessary to start the modelization process of out project. We have met with an expert in our project's field who is in the process of helping us come up with equations, variables, and assumptions. We have clearly defined our goal and are now ready to complete our project. We expect that the GABA neurotransmitter will be activated first. We also expect that with more consumption, the more the neurotransmitters will be affected.