It is estimated that our body contains around 1 billion neurons with about 1 trillion connections between them. When you feel that itch on your nose, it is because of neurons, when you feel the heat of the sun during a warm day, it is because of neurons, when you stub your toe and feel that excruciating pain, it is because of neurons. However, when we feel our emotions, it is also because of neurons. When you feel something, whether it be emotions, pain, an itch, or being tickled, it is because neurons are transmitting and receiving signals between each other. A neuron receives a signal through the dendrites. Once a signal is received, it sparks an action potential that travels down the axon to the terminal branches at the end of the neuron. These terminal branches connect to the dendrites of other neurons and this is how the signal travels. This junction between the dendrites and the terminal branches of neurons is called the synapse. Signals from one neuron are released by way of neurotransmitters which travel to the connecting neuron. The neurotransmitter connects to the dendrites of the receiving neuron and releases the signal which triggers another action potential. This process continues until the signal has reached its destination and proper action is taken.
As I previously mentioned, neurons are one of the factors for why we feel when we feel it. Depression affects millions of people around the world. One of the causes of depression are due to a lack of serotonin within certain people. Serotonin is a neurotransmitter that affects mood, hunger, sleep, and arousal. A lack of this neurotransmitter can lead to feelings of sadness or lack of feeling, lack of appetite, troubles sleeping, and other symptoms. One of the reasons people may have a lack of serotonin is due to serotonin uptake from the neuron. Once serotonin is released from the neuron, there are serotonin re-uptake sites that serotonin bind to. This means that some of the serotonin never reaches the next neuron, causing pretty much a serotonin deficiency in some people. However, there are certain drugs that can help. Prozac, which is one of the most commonly prescribed drug for depression is known as a SSRI (selective serotonin re-uptake inhibitor). It is an antagonist drug that inhibits the effect of a neurotransmitter. Prozac blocks the serotonin re-uptake sites so that it cannot re-enter the cell and can proceed to the connecting neuron.
My best friend since middle school has suffered with depression and anxiety for pretty much her entire life, as has her sister (names will not be mentioned for confidentiality purposes). When either of their depression gets bad, they describe their symptoms as feelings of sadness, lack of motivation, lack of appetite, and too little or sometimes too much sleep. They usually feel these symptoms when they have failed to take their medication for an extended period of time. They are both prescribed with Prozac. They likely are prescribed with Prozac in order to prevent the re-uptake of serotonin within their neurons. However, when they are properly taking their medication, they describe that they feel “normal” in a sense. They have a regular mood and appetite. This could be due to the fact that since Prozac is a SSRI, then their serotonin may reach a normal level.
(Please refer to this image for a visual of how serotonin affects the neurotransmitters and neuron)
Copeland, M., editor. “The Effects of Prozac on the Brain.” Packer
Intersections, 2019, www.packerintersections.com/
the-effect-of-prozac-on-the-brain.html. Accessed 19 Sept. 2019.