Right now, ask yourself how you feel; emotionally and physically. For example, at the moment I am writing this I am happy because I am looking forward to some ribs tonight from this great BBQ place called Q’s. At the same time, I am anxious because I have to teach in five days when school starts for the year. My left shoulder is sore because I hurt it last year in a collision at home plate in the Westchester Temple softball league (Jewish men and softball is a dangerous combination- if you want to see the championship video recap for Larchmont Temple- my team click here). I am thinking about where this example is actually going. Oh yeah, I am also feeling some pressure deep down in my bowels (probably from the vegetarian burrito from Harry’s Burritos last night) and I am looking forward to some quality reading time on the porcelain throne.
The point is that every feeling, thought and emotion I have are due to millions of small nerve cells called neurons. Without these neurons working and carrying messages throughout our body we would feel and be able to do nothing, kind of like a normal day in math class.
So the first and most basic structure in the biological school of psychology is the neuron which kind of looks like:
These neurons send information throughout our whole body. Let’s go through the specific parts of a neuron and their functions (isn’t this edge of your seat, biting your fingernails exciting?)
| Neuroanatomy | Function |
| Dendrites | The root like part of the cell that stretches out from the cell body. Dendrites will receive messages from other neurons by grabbing on to neurotransmitters (chemicals we will talk about soon). |
| Soma (cell body) | Contains the nucleus (brain) of the cell. Tells the cell to fire of not to fire. |
| Axon | Wire like structure that extends from the soma to the axon terminal buttons. It is like a highway in which the messages will travel down the neuron. |
| Myelin Sheath | A fatty layer of tissue that surrounds the axon. It helps speed up neural impulses. |
| Axon Terminal Buttons | The branches at the end of the axon that contain neurotransmitters and send them shooting across the synapse. They also suck up excess neurotransmitter in a process called reuptake. |
| Neurotransmitters | Chemicals contained in the terminal buttons that enable neurons to communicate. Neurotransmitters fit into receptor cells on the dendrites on other neurons like a key in a lock. |
| Synapse | The space in between neurons (neurons never touch each other). |
Ok- when a neuron is hanging out doing nothing, it is called resting potential and it has a slightly negative charge inside of it. When a neuron decides to go to work its called action potential (the process by which a neuron fires). Action Potential is a electro-chemical process, which means half of the job is electrical and half is chemical.
Lets explain action potential by talking about three neuron buddies named Bikita, Fabian and Joe. There is a rumor going around that Joe’s girlfriend is cheating on him with a toenail cell, but Joe does not know about it yet. Lets call that rumor a neurotransmitter (chemical messengers that run throughout our body). Pieces of the rumor (neurotransmitter) first get shot over to Bikita and stick to her dendrites. Bikita cannot send the rumor along because she is not yet sure it is true and does not want to hurt Joe’s feelings. When enough of the rumor (neurotransmitter) is attached to Bikita’s dendrites it hits her threshold and she cannot hold it in any more (she has to tell Joe). She does not believe in telling just a bit of the story, she wants to tell the whole damn thing (called the all-or-none response). So Bikita opens up a portal on her axon and lets in positive ions into her causing an electrical charge. The electrical charge travels down the axon to the axon terminal (or terminal buttons) where the rumor (neurotransmitter) is stored to tell the next neuron. The rumor is shot across the gap in between Bikita and her buddy Fabian called the synapse. Fabian uses his dendrites to collect the rumor so he can proceed to use action potential to send the process to Joe. When Fabian has had enough of the rumor and decides to send the information to Joe, he signals Bikita to stop send messages (neurotransmitter). Bikita will then suck up the rest of the rumor (neurotransmitter) that is in the synapse in a process called reuptake. It you actually understood any of this you are a freakin genius because that may be the worst analogy of all time. I better go over this in detail in class!!!
Just like there are different rumors in your school, there are different neurotransmitters in your body. Just like various rumors will effect you differently, various neurotransmitters do different things to your body. I CANNOT underestimate how important these chemicals (neurotransmitters) are to our body. Everything we do, we need a neurotransmitter to do well. Every time you move, think, smile, or even feel emotion; you are at the mercy of your neurotransmitter.
Here are the important ones you should know for the AP Exam.
| Neurotransmitter | Function | Issues with it. |
| Acetylcholine (ACH) | Motor Movement and Memory | To much you spasm. Too little you do not move. Lack of it has been linked to Alzheimer’s disease. |
| Dopamine | Motor movement and Alertness | Lack of it has been linked to Parkinson’s disease. Too much of it has been linked to schizophrenia. |
| Endorphins | Pain Control | Involved in addictions. |
| Serotonin | Mood Control | Lack of it is linked to depression. |
Neuron Definition Psychology
Now although we have all of these neurotransmitters naturally in our bodies, modern medicine has figured out a way to manipulate them using what we call drugs.