Codes for depression

As a student of science and psychology, I am interested in learning about inherent biological mechanisms that are responsible for the various external experiences we go through on a daily basis. Why do people act the way they do, or why do humans feel a certain kind of way when watching a sad movie, or a funny movie or a scary movie?

Module 15.1, addresses the broad topic of Mood Disorders.

I wanted to know specifically about the chemical responsible for "depression". Why do we feel sad or down during not so happy times? What makes us feel that way? well, there are many factors that can help explain this mechanism, but in this post, I will talk mainly about the chemical imbalance in the brain.

Neurotransmitters, which are chemicals responsible for relaying most neural information from one neuron or nerve cell to the next have been helpful in explaining the case of depression.

The cause of depression, is dependent upon the volume or amount of these neurotransmitters being communicated throughout the neural pathways. If there is too much or too little then there is an imbalance or a breach to homeostatic event, which can then lead to the person feeling depressed or sad. The family of neurotransmitters that have been linked to depression are all classified in a group called monoamines which are further classified into three: 

Serotonin, Dopamine, and Norepinephrine

Low levels of monoamines cause depression in humans. One study have found that high levels of an enzyme responsible for breaking down serotonin, the Monoamine Oxidase-A (MAO-A), is significantly higher in cases of depression. 

Chemically, that is the explanation. Physiologically, the parts of the brain depression is most prevalent are: 

The Amygdala, Thalamus, Hippocampus.

Depression, once again, is experienced by the human in effect of a biological mechanism... Some argue that this is not the only cause of depression, things like the environment, and genetics also influence the occurrence of depression. However, for me chemically and biologically explained is much more satisfying. If you want to learn about the physical effects of depression, I have included an image below: 

Good luck and happy day! 

The Immune-Brain Loop and Stress

So the title might boggle you, because you did not come across that specific terminology in the text. But in fact it is just another synonym we did visit in the text: psychoneuroimmunology. I was interested in this topic because it explains a relationship between the immune system (yes) and the central nervous system. Yes, in fact, chemicals involved in fighting infection can be linked to emotional feelings like depression and other mental mechanisms.

To illustrate, first I must introduce what is called the HPA axis which stands for the hypothalamus-pituitary-adrenal cortex.

The image below depicts what happens when a stimulus of stress is introduced via externally (i.e., you experience through your sense of sight, smell, touch, etc.). It leads to a cascade of responses that involves the HPA axis. First response, through the hypothalamus, which releases CRF and so on....

Stress is a broad term. It can change its meaning and purpose if you place "stress" in a different context. Like in psychology, when we mention stress, we immediately associate it with emotions, like frustration or anger. However, in physical biology, stress means an injury. A physical trauma to the foot or finger or what have you. And the immune system is directly involved in eradicating stress to the physical aspect of your body. Levels of white blood cells (WBCs) that fight infection, such as cytokines and natural killer cells, are elevated in response to a physical stress like a cut in your bleeding finger, etc. But it has been shown that elevated levels of cytokines, are also correlated with emotional stress. One explanation is that (as shown in the table below) increased cortisol production directs its energy to increasing metabolism and therefore detracts energy synthesizing proteins. In other words, increasing the cortisol production will lead into a deprivation of normal levels of B cells, T cells, and natural killer cells, which are all WBCs found in the immune system. Having low levels of WBCs mean depression and extreme sadness.

Prolonged stress also harms the physiological aspect of the brain. In the hippocampus elevated levels of cortisol can mean toxicity that eventually leads to damage in the neurons of the hippocampus, which is responsible for maintaing stability in emotional pursuits.

The Pain Killers

I thought I'd start off with that powerful quote by Murakami. Although it might seem irrelevant to the topic I will address, I thought it was a good opening statement. Pain for humans can be experienced physically, psychologically or emotionally. And pain is not a good sensation. It hurts, no matter where we experience it. But it is a necessary fact we have to accept in life. 

Despite the unpleasant feeling it gives, pain is actually a natural response our body makes for survival. Pain, as humans experience it, hurts but biologically our body is repairing itself or working its defense system for the "harmful" stimuli that it encountered. Fortunately, there are ways to relieve pain for the human experiencing the side effects of this physiological response. For example, if we happen to have a burn on our hand, we can rub it repeatedly, so the intensity of the pain will diminish. It's as if by rubbing, we're numbing the feeling of the pain. If we're experiencing a headache or a muscle ache, we can ingest over the counter medications like Tylenol to relieve the pain. Also think of the "fever". That feverish feeling that we call as "being sick" is actually our body's immune system attacking the virus that invaded our body cells, to help us survive. Humans just interpret it differently than our physiological system. It's pretty neat stuff.

For this particular blog, I will illustrate the use of Over-the-Counter Pain Medications and its uses for both physical and emotional pain.  

Those are the generic names for the many brands available for over the counter pain relief medications (aka analgesics). And if you recall from our readings, acetaminophen (Tylenol) have actually been linked, in addition to physical pain relief properties, to relieving "hurt feelings" as well. Acetaminophen, as depicted in the illustration above, is best for headaches and toothaches. However, it has also been found in the brain to diminish responses in the cingulate cortex (responsible for emotional pain). Interestingly, researchers found used in this study, subjects taking acetaminophen progressively show less frequency in hurt feelings! 

I know there are much more complex and intricate explanations out there about the mechanisms and pathways of drug interaction in the human body system, but this is what I found interesting. I find it interesting how our bodies react pain and how we as humans interpret this biological mechanism. Everything that we experience can have a biological explanation. Of course I will sound biased because I am getting my inspiration from our biological physiology book, but this is one explanation that is scientific and factual, free of ambiguity. 

Effects of Stress on Memory

I want for you to take a minute and watch a clip below from the National Geographic channel titled Brain Games! It is an interactive, as well as informative, video where they have a memory matching game in the beginning to do yourself! Give it a go! 

That was pretty neat right?! All right let's move on… 

If you recall from our textbook, emotionally significant memories form quickly. This is because emotions increase adrenaline (epinephrine) and cortisol in the hippocampus and amygdala where the brain enhances the storage and consolidation of recent experiences, i.e., better memories. But what happens when the same chemicals are elevated continuously in our system? And how do these levels affect human memory in the long run? Will it have a positive or negative effect? 

To answer, take a quick look at the image below. It illustrates how a type of stress, called chronic stress, negatively affects human memory. 

Adrenaline and cortisol are natural occurring chemicals in our body that are apparent for homeostasis. In fact, initial stages of adrenaline insurgence can cause a feeling of euphoria (i.e. adrenaline junkie) and is necessary for fight-or-flight to cope in fear-causing situations, but prolong stress (or abnormal levels of both chemicals) actually result to memory impairment. 

The hippocampus, amygdala and prefrontal cortex are the brain structures associated with memory. Glucocorticoids are stress chemicals that directly impair memory. Cortisol is a bio-marker that triggers the impairment of memory. Adrenaline is a stress hormone used for flight-or-fight situations, how humans cope with stressful situations for survival. 

Below is a chemical structure of the stress hormone cortisol

Below is adrenaline

In conclusion, stress negatively affects memory if the chemicals associated with it are imbalanced. If not observed early, it can not only affect our emotions but our cognition as well. I found a neat chart that exposes stress we can experience in different human levels. I thought I could also benefit from this in the future: 

 

So now you have an idea about the negative consequences of seemingly good chemicals in our memory and emotional wellness. I want to know if this inspired you to change something in your life regarding stress? Also, I would appreciate your own strategies on how to cope with stress! Comment below! Thank you!  

Impact of Meditation on Attention

We've all heard about meditation. And we've seen others do it. But have you ever wondered why they do it? And how? In this post, I will attempt to outline some of the numerous benefits of this silent practice to inspire you to change the way you think about the ritual, or if you've never cared about it, I will attempt to make you take a second look!

So what is attention? According to Merriam-Webster, it is "the act or power of carefully thinking about, listening to, or watching someone or something"

Attention is an important component of making humans an animal capable of higher forms of cognition. At this very moment, you are only focusing on reading this passage (or so I hope) and not even aware of other stimuli bombarding you, like the sensation of your clothes against your skin, or how your legs are positioned while reading this visual text. But I bet now I have turned your attention to the feeling of your clothes against your body or the position of your legs simply through reading! You've now become aware of all those other things, while still reading this text! How cool is that right? Absolutely cool! 

So where in the brain exactly is attention processed? Well neuroscientists have associated attention to the cerebral cortex, the largest component of the human brain that covers both left and right hemispheres: (Click on image to expand) 

The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex. The dopamine is a chemical in the brain that is associated with the reward system, attention, short-term memory tasks, planning and motivation. Basically it's what makes humans the smartest of all animals! 

So now we know about the physical structure of attention on the brain. How does meditation associate with attention and what are its benefits? A study done by Eileen Ruders and colleagues at the UCLA Laboratory of Neuro Imaging have found that long term meditators have larger amounts of gyrification (folds and fissures that compress cerebral cortex) compared to those who do not practice meditation. Neuroscientists believe gyrification is responsible for making better decisions, stronger at forming memories, and improving attention. 

There are numerous other literature review out there that are done specifically on meditation and attention, but the key message is that there are physical changes to the brain (good changes) that directly impact human attention. 

Below is an image that charts a number of researches done on the many benefits of meditation, not just attention: 

To close I will include an informative chart that appeals to the student. Enjoy! 

Let's plant some stem.... cells!

Yep... That cartoon is just one example of an opinion among many others, concerning the controversy that encircles stem cell research... Ok so what exactly makes stem cell research "controversial?" Well before I get into that I did some investigating about the basics of stem cells and how it develops in the human body:

1. Stem cells are formed in the bone marrow and are undifferentiated, meaning they can become any type of cell that the body needs in order for it to survive and continue living without complications.
2. Stem cells can either be embryonic or non-embryonic (adult) cells.
3. Embryonic cells will develop on to become a fetus. The embryo is the union of an egg and sperm cell, later develop into a fetus.
4. Non-embryonic (adult) cells are repairable and found in both children and adults.
5. In-vitro fertilization (IVF) is the destruction of the embryonic cell and is performed in laboratories. Instead of continuing in the womb, the embryo that is 3-5 days old, is taken from the mother (with consent from the couple, or mother) and cultured in the lab to commence the study.

Below is an image of the manipulation of an embryonic stem cell in a research lab... This is the most focused stem cell research and the one that poses much controversy in society. The reason why researchers focus on this study particularly, is because the embryonic cell has the potential to become any cell in the body that can provide cure, if researchers find a way...

Perhaps the main cause of the controversy that surrounds stem cell research, is the varying opinions about where life begins... Opponents argue that the embryonic stage (the mere fusion of egg and sperm cells) should already be considered as the start of life and tampering with that, is posing harm to the "person." Supporters of the research, on the other hand, argue against it. They believe there is no harm being done since it is still too early in the development for it to be considered a real human being.


So where should we stand? Now that we have been making progress not only on technological development, but also in medical advancement? Are we going on the right direction here? There are still research out there hoping to find a cure. Should we still persist? Or should we not resist the degeneration of life as it presents to us? There have been more questions now than ever before. Is that a good thing? Where do you think we are headed in terms of curing diseases?

Below is a neat image that illustrates the potential benefits of stem cell research to the ailments of the human body...

Please voice your opinions in a comment down below! Thank you! 

The Science Behind Addiction

Why does addiction exist? Why do people get addicted? Well just like any external experiences we go through,  there are scientific and biological explanations that can help demystify such occurrence. So let's dive right in!

It is a common fact of life that people are exposed to different stresses and worries everyday. And often times, people medicate with drugs and harmful substances to cope. Drugs like alcohol and marijuana have chemical substances that not only suppresses the pain associated with our stress, but most importantly provide a shortcut to the brain's reward system or pleasure center by flooding the Nucleus Accumbens in the brain with high and intense doses of a satisfying chemical, called dopamine. This chemical is associated with euphoric feelings we experience such as having sex, eating your guilty-pleasure food, gambling and shopping.

Below is an image illustrating the brain's Reward Center:
Nuclues Accumbens - highly related to addiction because of drug's effect of high release of dopamine

Click on image to expand

Dopamine is a double-edged sword because not only does it make drugs feel good ("getting high") but it also plays a role in learning and memory- which is a crucial element in learning to like something to learning to become addicted to the same thing.

Chemical Structure of Dopamine

But don't fret, just like your brain learns how to become addicted to shopping or alcohol, it can learn to get away from that as well over time. As mentioned, drugs are addictive because they can intensify the doses of dopamine from 2 to 10x as much in the brain. But over time, the brain can be overwhelmed, which means producing less dopamine or eliminating dopamine receptors. People with addiction, over time, have to take even stronger doses of their drug because they have developed a level of tolerance.

I found a diagram that illustrates the different brain structures and the behaviors associated with it, all from the perspective of dopamine receptors!

Addiction is a tricky thing. We possess biological characteristics that can interact with substances, that may not be harmful by itself, but coupled with the chemicals in our brain can become harmful to us, because of a strong chemical reaction. We, often times, do not know what we are capable of. And that lack of awareness of ourselves, in return, can be the gateway to our own addiction and abuse.