The Brain Lesson Plan

The Brain: What is going on in there?

Time: 45 minutes

Overview

At the end of this lesson, people will learn that neurons are the functional unit of the brain and understand the hierarchical organization of the brain. Students will learn how neurons convey, and interpret information. Students will also understand how neurons communicate using electrical impulses and how chemical messengers also known as neurotransmitters activate or inhibit neurons. Students will also be introduced to my current research on depression and how it affects the population and activity of neurons in the brain.

Lesson Objectives At the end of this lesson students will understand:

1. How the brain is organized, and that the neuron is the basic unit of the nervous system 2. How neurons communicate at their synapses 3. How chemical messengers, also known as neurotransmitters, can either excite or inhibit neurons 4. The changes that current research has found to occur in people suffering from depression

Background Information

What is the brain?

The brain is the most important organ of the body. The brain controls how we think, what we feel and how we act. The brain also controls body functions such as breathing, sleep, our heart rate and body temperature. The field of neuroscience studies the brain and the nervous system. The field of neuroscience studies how people control their behaviors, thoughts, and feelings, and how these actions sometimes get out of control. The brain is responsible for processing a huge amount of information in a remarkably efficient manner. Most of the activities that we do without thinking such as driving a car involves a number of tasks that are processed by the brain.

How does the brain carry out multiple tasks at one time?

The brain splits larger tasks into smaller ones. Each part of the brain is divided into special parts that analyze smaller information to create a bigger picture. For example, the back of the brain, called the occipital lobe, specializes in seeing while the side portions of the brain called temporal lobe is responsible for hearing. The downside to this type of organization is that if there is anything wrong with one part of the brain, that part cannot perform the function it is designed to do. For example, if there is something wrong with the occipital lobe of a person, that person may loose his or her sight without any impairment in hearing or smell. This way of information processing is referred to as parallel processing and has been used in the development of computers.1

How does the brain communicate with the body?

The brain communicates with the body through the help of nerves. Nerves can be seen as the extension of the brain and they carry information about the way we feel to the brain. For example if you put your hands in cold water, the nerves in your hands carry the information from the water (known as the stimulus) to your brain which then interprets this information to you as the water being cold. There are millions of nerves in the body and these nerves communicate with each other via chemicals known as neurotransmitters and these are secreted by nerves. There are various types of neurotransmitters in the body and nerves are classified based on the types of neurotransmitters that they secrete. For example, nerves that secrete dopamine, the neurotransmitter that plays a major role in alertness and mood are called dopaminergic neurons.

How do drugs affect the brain?

The part of the brain that controls our emotions and motivations is referred to as the limbic system. The limbic system controls how we respond to the world around us. The limbic system uses memories, information about how your body is working, and current sensory input to generate your emotional responses to current situations. The limbic system is composed of various parts namely the amygdale which plays a major role in anger, and the hippocampus, which plays a major role in learning and memory. Drugs can affect how neurotransmitters are released and broken down in the limbic system, and thus affect the way we respond to our environment. For example, cocaine blocks the reuptake of dopamine into the neuron, which prolongs the effects of dopamine. There is a lot of ongoing research in the role of the limbic system in depression and how anti depression drugs affect neurotransmitters in the human body.

Materials needed:

1. Projector 2. computers 3. pencils and paper

Procedure:

1. Have a brief 20 minute introduction of the brain with the students. Define what the nervous system is and how the brain fits into the nervous system. It is important that students realize that the neuron is the functional unit of the nervous system just as the cell is the functional unit of the body. Then explain the roles of neurotransmitters in the nervous system. Make mention of the types of neurotransmitters and how they either excite or inhibit neurons in the nervous system. 2. Divide students into groups with no more than three to a computer. There are a series of activities that involve critical thinking that students will perform. Select a leader for each group and instruct the leader to write their response to the activities which would be presented later on in class. This should take no more than 10 minutes. The activities are designed to acquaint students with the brain, how it functions, and how neurotransmitters work. Most of these activities are available at www.scicenceposse.org 3. Have each group report their results of the critical activity which should take no longer than 10 minutes. 4. I will then present the results of my research to the class with videos showing the roles of neurons in depression in the brain of rats.