This week’s reading on Neurobiology reminded me why I am an English Major. I have no interest in science (beyond chemistry, which helps with cooking) and lack the ability to understand “sciencey” words.
“A single cubic centimeter of the human brain may contain well over 50 million nerve cells, each of which may communicate with thousands of other neurons in information-processing networks that make the most elaborate computer look primitive.” (Campbell and Reese qtd in “Neurobiology,” 1).
What intrigued me the most about the reading was that neurons communicate constantly. I immediately thought of the communication networks that many of us depend on today. We are constantly communicating in some way, using some technology. Neurons primary activity is cellular communication. This system has billions of neurons and trillions of connections. What does neurotransmission look like?
There are big neurons and small neurons. Each neuron has two ends dendrite (tree that branches) and axon. The axon end is made up of presynaptic neuron and the postsynaptic neuron. The interesting part of this, to me, were the vesicles. The vesicles–described as soap bubbles–enable neurons to listen and talk at the same time. Vesicles are loaded with transmitters and stand-by waiting for release the neurotransmitters. What was inside the vesicle ends up outside of the cell (exocytosis).
This entire process reminded me of HowStuffWorks? from the beginning of the term. The discussion of computers, WiFi and Mobile, and Networking. We examined hardware systems and the infrastructure needed for our devices. There are several networks that work together to allow our devices to function and to allow them to communicate with one another. As complex as all this seems, it has nothing on the connections that neurons make. Neurons transmissions are highly complex. Neurons use “both electrical and chemical communication” (1). This complexity is exemplified by the fact that the neuron, as sophisticated as it may be, is assisted by other cells in the brain (glial cells).
Another aspect of the journey into neurobiology that intrigued me was the nerve impulse, or action potential. This is “a series of electrical responses that occur in the cell” (4). Action potential requires depolarization in the membrane, which allows sodium channels to open up. The sodium ions enter the axon, causing a change in charge. One the voltage becomes positive the channel becomes inactive, and the potassium channels open. The potassium ions exit the axon, causing the charge to change to negative. These channels stay open until the membrane “becomes even more negative than the resting potential for a brief period” (4). The action potential lasts only a few milliseconds (Amazing!). This entire process made me think of magnets. The switching of positive to negative moving the nerve impulse along the axon. I also thought of Leslie’s post on buses. Buses allow data to transfer from one component to another. Both focus on transferring, moving information, through the network.
This foray into neurobiology was not as horrible as I thought it would be. The neuronal network is quite remarkable. We learn about all this in school, but I never noticed the communication aspect. The neuronal network is all about communicating and transmitting. It is receiving data and transmitting data simultaneously. It moves the information forward and has a system in place to prevent information from going backwards and causing confusion in the system (sodium channel refractory period). The neuronal network is replicated (accidentally? intentionally?) all around us in the devices that we use everyday.
Action potential or nerve impulse also made me think of Snapchat. The movement of the nerve impulse forward via the opening and closing of channels and the inability of information to be sent backwards made me think of Snapchat communication as a nerve impulse. The user taking the snap after being sparked by an event or situation. The user receiving the snap and having that small window of time in which to consume the information. This entire process is not as fast as a nerve impulse and much simpler, but worth exploring.
Does, Amy, Johnson A. Norman, and Teresa Thiel. “Unit 10: Neurobiology.” Rediscovering biology: Molecular to global perspectives. (n.d) . Web. 31 March 2014.