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Biomedical Research Health and Disease

Stem Cells: Why Are They So Crucial In Medicine?

Stem Cells constitute an intriguing and promising field of medicine because of their ability to regenerate and heal damaged tissue. This article covers the biology of stem cells, the pros and cons, and their promising abilities to further our study of medicine.

Introduction

Stem cells are the raw materials of the body, the cells that give rise to all other cells with specialized roles. Under the appropriate conditions, these unique human cells can develop into a variety of cell types by dividing themselves to generate new cells known as daughter cells in the body or in a laboratory. This can include everything from muscle cells to brain cells. In some situations, they can also repair damaged tissues. These daughter cells can either continue to differentiate into new stem cells or can become specialized cells with a more narrowly defined function, such as bone, brain, heart, or blood cells. No other cell in the body has the capacity to naturally produce different cell types. Because of these distinguishing traits, stem cells have historically been assumed to be everlasting and ageless.

Types of Stem Cells 

Every organ and tissue in your body is built on stem cells. There are numerous types of stem cells that originate in various parts of the body or form at various stages throughout our lifetimes. These include embryonic stem cells, which exist only during the early stages of development, as well as other types of tissue-specific (or adult) stem cells, which appear during fetal development and remain in our bodies throughout our lives. All stem cells have the ability to self-renew (produce copies of themselves) and differentiate (develop into more specialized cells). Aside from these two fundamental capacities, stem cells differ greatly in what they can and cannot do, as well as the conditions under which they can and cannot do specific things. To begin with, there are three fundamental types of stem cells: Embryonic Stem Cells, Adult Stem Cells, and Induced Pluripotent Stem Cells.

  • Embryonic Stem Cells

Embryonic stem cells are extracted from the blastocyst, a mostly hollow ball of cells that forms three to five days after an egg cell is fertilized by a sperm in humans. The size of a human blastocyst is around the size of the dot above this “i.” During normal development, the cells within the inner cell mass give rise to the more specialized cells that give rise to the complete body—all of our tissues and organs. When scientists extract the inner cell mass and cultivate it in a particular laboratory environment, the cells retain the qualities of embryonic stem cells. Embryonic stem cells are pluripotent, which means they can give rise to every cell type in the fully developed body save the placenta and umbilical cord. These cells are extremely significant because they provide a sustainable supply for researching normal development and disease, as well as evaluating medicines and other therapies. Human embryonic stem cells were predominantly produced from blastocysts developed by in vitro fertilization (IVF) that were no longer required for assisted reproduction. (3) Scientists seek to learn more about how these cells differentiate as they develop. As we learn more about these developmental processes, we may be able to apply them to stem cells produced in a lab and maybe regenerate tissues like the liver, intestines, nerves, and skin for transplantation. (4).

Figure 1: The Journal Of Clinical Investigation 

  • Adult Stem Cells

Adult stem cells, also known as somatic stem cells, are undifferentiated cells found in nearly all creatures’ bodies, including humans, in a variety of organs. Adult stem cells, which have been found in a variety of tissues including skin, heart, brain, liver, and bone marrow, are normally restricted to becoming any type of cell in the tissue or organ in which they dwell, as opposed to embryonic stem cells, which can become any cell in the body. Adult stem cells are believed to be multipotent, meaning they can differentiate into certain types of body cells exclusively, not into any type of cell. (6). These adult stem cells, which can live in tissue for decades, replace cells that are lost in the tissue as needed, such as the daily generation of new skin in humans. (5). Most adult tissues, including bone marrow and fat, contain a tiny amount of these stem cells. Adult stem cells, in comparison to embryonic stem cells, have a more limited potential to give rise to various bodily cells. Adult stem cells were thought to only be capable of producing comparable types of cells until recently. For example, researchers previously believed that stem cells found in bone marrow could only give rise to blood cells. However, new research reveals that adult stem cells can generate a variety of cell types. For instance, bone marrow stem cells might be able to develop into heart or bone cells. This research has resulted in early-stage clinical trials to assess the usefulness and safety of the product in humans. (1)

Using genetic reprogramming, scientists successfully turned ordinary adult cells into stem cells. Researchers can reprogram adult cells to behave like embryonic stem cells by modifying their DNA. This new technology may allow for the use of reprogrammed cells rather than embryonic stem cells, as well as the prevention of immune system rejection of the new stem cells. However, scientists are unsure whether employing changed adult cells will have a negative impact on humans. Researchers were able to transform ordinary connective tissue cells to become functioning heart cells. In experiments, animals with heart failure who were injected with fresh heart cells had better heart function and survival time.(1)

Types of Adult Stem Cells 

  • Hematopoietic Stem Cells (Blood Stem Cells)
  • Mesenchymal Stem Cells
  • Neural Stem Cells
  • Epithelial Stem Cells
  • Skin Stem Cells

Figure 2: Sciencedirect

  • Induced Pluripotent Stem Cells 

Induced pluripotent stem (iPS) cells are lab-engineered cells that have been transformed from tissue-specific cells, such as skin cells, into cells that act like embryonic stem cells. They are a happy medium between adult stem cells and embryonic stem cells. iPSCs are generated by inserting embryonic genes into a somatic cell (such as a skin cell) and causing it to return to a “stem cell like” state. IPS cells are important tools for scientists to understand more about normal development, illness start and progression, and for creating and testing new medications and therapies. While iPS cells share many of the same properties as embryonic stem cells, such as the potential to give rise to all cell types in the body, they are not identical. Scientists are trying to figure out what these distinctions are and what they represent. For starters, the first iPS cells were created by inserting extra copies of genes into tissue-specific cells using viruses. Researchers are exploring a variety of methods for creating iPS cells, with the goal of eventually using them as a source of cells or tissues for medical therapies. One example is that the first iPS cells were created by inserting extra copies of genes into tissue-specific cells using viruses. (3). These cells, like ESCs, are thought to be pluripotent. This method of genetic reprogramming to make embryonic-like cells, discovered in 2007, is unique and requires several more years of research before it can be used in clinical therapy. (4). 

The Importance Of Stem Cells

Stem cells may benefit your health in a variety of ways and through a variety of novel treatments in the future. Stem cells, according to researchers, will be used to help build new tissue. For example, healthcare providers may one day be able to treat patients with persistent heart disease. They can accomplish this by cultivating healthy heart muscle cells in the lab and transferring them into damaged hearts. Other medicines could target type 1 diabetes, spinal cord injury, Alzheimer’s disease, and rheumatoid arthritis. New treatments could potentially be evaluated on pluripotent stem cell-derived cells.

Stem cells, with their unique regeneration powers, hold fresh promise for treating diseases such as diabetes and heart disease. However, substantial work in the laboratory and clinic remains to be done to understand how to employ these cells for cell-based therapies to cure disease, often known as regenerative or reparative medicine. Laboratory studies of stem cells allow scientists to understand about the cells’ basic features and what distinguishes them from other types of cells. Scientists are already employing stem cells in the lab to test novel medications and create model systems for studying normal growth and determining the reasons of birth abnormalities. Stem cell research continues to enhance understanding of how an organism grows from a single cell and how healthy cells replace damaged cells in mature creatures. Stem cell research is one of the most exciting areas of modern biology, yet, like with many burgeoning domains of scientific endeavor, it raises scientific concerns as quickly as it generates new discoveries. (4)

Although adult stem cell research is encouraging, adult stem cells might not be as adaptable and resilient as embryonic stem cells. The potential for using adult stem cells to cure diseases is constrained by the fact that not all cell types can be produced from adult stem cells. Adult stem cells are also more likely to have abnormalities because of chemicals or other environmental dangers, or because the cells made mistakes during replication. Adult stem cells, on the other hand, have been discovered to be more versatile than previously imagined. (1).

Stem Cell Line

A stem cell line is a collection of in vitro-grown cells that all descended from a single initial stem cell. A stem cell line’s cells continue to multiply without differentiating into other types of cells. Ideally, they continue to produce more stem cells and are genetically flawless. From a stem cell line, groups of cells can be extracted and shared with other researchers or frozen for future use.

Potential Therapies using Stem Cells 

Regenerative medicine, often known as stem cell therapy, uses stem cells or their metabolites to stimulate the body’s natural healing process in diseased, dysfunctional, or injured tissue. It is the next step in organ transplantation and employs cells rather than donor organs, which are in short supply. In a lab, researchers cultivate stem cells. Through manipulation, these stem cells can be made to specialize into particular cell types, such as heart muscle cells, blood cells, or nerve cells. The specialised cells can then be injected into the patient. If the patient has cardiac issues, the cells might be injected into the heart muscle, for example. The transplanted, healthy heart muscle cells could then help the injured heart muscle repair.

Embryonic Stem Cell (ESC) Therapies

ESCs have the potential to treat some diseases in the future. Scientists are still learning how ESCs differentiate, and once this process is more understood, the objective is to apply what they’ve learned to get ESCs to develop into the cell of choice that is required for patient therapy. Diabetes, spinal cord injury, muscular dystrophy, heart illness, and vision/hearing loss are among the diseases being treated by ESC therapy. (4) 

Adult Stem Cell Therapies

For more than 40 years, bone marrow and peripheral blood stem cell transplants have been used to treat blood illnesses such as leukemia and lymphoma, among others. Scientists have also discovered that stem cells may be found in nearly all parts of the body, and research is ongoing to learn how to identify, remove, and multiply these cells for future application in therapy. Scientists want to develop treatments for ailments such as type 1 diabetes and cardiac muscle restoration after a heart attack. Scientists have also demonstrated the potential for reprogramming ASCs to cause them to transdifferentiate (revert to a cell type other from the one it was replenishing in the local tissue). (4)

Induced Pluripotent Stem Cell Therapies

Therapies based on iPSCs are intriguing because recipient somatic cells can be reprogrammed to a “ESC like” state. The necessary cells could then be produced by using processes to differentiate these cells. This appeals to physicians because it avoids the issue of histocompatibility and lifelong immunosuppression, which is required when donor stem cells are used in transplants. iPS cells are pluripotent cells that mirror most ESC traits, but they do not currently carry the ethical baggage of ESC study and use because iPS cells have not been induced to grow the outer layer of an embryonic cell essential for the cell’s growth into a human individual. (4)

 Pros and Cons of Stem Cells

Figure 2: University of Nebraska Medical Center: Types of Stem Cells

Potential Problems in using Stem Cells

Stem cells require considerably more research before their use may be increased. Scientists must first discover more about how embryonic stem cells develop. They will learn how to manage the kind of cells that are produced from them thanks to this. Using adult pluripotent stem cells presents difficulties for scientists as well. Researchers are trying to find a better approach to cultivate these cells because they are challenging to do so in a lab. The body also contains trace amounts of these cells. There is a bigger possibility that they will have DNA issues.

 Another issue is that the embryonic stem cells that are now available are likely to be rejected by the body. Additionally, some people believe that using stem cells derived from embryos violates moral principles. For embryonic stem cells to be effective, researchers must be confident that they will develop into the required cell types. Researchers have identified ways to control stem cells to become specific types of cells, such as directing embryonic stem cells to become heart cells. In this field, research is underway. Additionally, embryonic stem cells have the capacity to develop erratically or innately specialize in certain cell types. Researchers are investigating how to control the proliferation and differentiation of embryonic stem cells. Embryonic stem cells could possibly set off an immunological reaction in which the body of the receiver assaults the stem cells as foreign invaders, or they could simply stop working as they should, with unknown repercussions. Researchers are still investigating how to prevent these potential complications. (1).

Akshaya Ganji, Youth Medical Journal 2022

References 

  1. MayoClinic: Stem cells: What they are and what they do-https://www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art-20048117
  2. Standard Medicine: What Are Stem Cells?-https://www.stanfordchildrens.org/en/topic/default?id=what-are-stem-cells-160-38 
  3. A Closer Look at Stem Cells: Types of Stem Cells-https://www.closerlookatstemcells.org/learn-about-stem-cells/types-of-stem-cells/ 
  4. University of Nebraska Medical Center: Types of Stem Cell-https://www.unmc.edu/stemcells/educational-resources/types.html 
  5. University of Notre Dame: Adult Stem Cells-https://stemcell.nd.edu/research/alternative-stem-cell-sources/adult-stem-cells/ 
  6. Yo Topics: What is a stem cell?- https://www.yourgenome.org/facts/what-is-a-stem-cell/ 
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Neuroscience

The Neuroscience Behind Emotions: Exploring The Science Behind Emotions 

Introduction

 Our daily lives are significantly impacted by our emotions. The emotions you encounter on a daily basis can spur you to action and have an effect on both major and minor life decisions. They can either be short-lived, or long-lasting. We make decisions based on how pleased, angry, depressed, bored, or dissatisfied we are. We choose activities and hobbies based on the feelings they elicit. Understanding these different types of emotions can help us navigate life more easily and steadily. (3). According to the Project on the decade of the brain: “The Science of Emotion”, emotions are a brief period of synchronized brain, autonomic, and behavioral changes that aid in responding to an event. They are a highly adaptable type of physiological response that governs our existence and are low-level responses that are encoded in our DNA. Emotion is mostly exhibited in the body’s theater, through posture and facial expression, as well as through internal processes such as heart rate and blood pressure. Feelings are high-level responses that provide a mental and perceptual representation of what is happening physiologically inside our bodies. 

What are Emotions? 

Authors Don Hockenbury and Sandra E. Hockenbury claimed in their book “Discovering Psychology” that an emotion is a complex psychological state with three separate components: a subjective experience, a physiological response, and a behavioral or expressive response. (4). In addition to attempting to explain what emotions are, scholars have attempted to identify and categorize the various sorts of emotions. Over time, the explanations and insights have evolved.

Emotions are reactions that people have in response to events or situations. The circumstance that causes the emotion determines the type of emotion the individual feels. There are four major emotions: happiness, sadness, fear, and anger, which are associated with three core affects: reward, punishment, and stress. The fundamental emotions are internal states that are controlled by neuromodulators. These internal states are expressed externally as certain stereotypical actions, such as instinct, which is thought to be one of the first means of survival. (2). According to the study on Drosophila and other insects, it states that emotion is essential in both regular human experience and psychiatric diseases. Despite the importance of emotion, the relative absence of objective approaches for scientifically examining emotional phenomena restricts our existing understanding and hence necessitates the creation of novel methodologies. To add on, using behavioral studies of Drosophila, they have created a theory of the fundamental emotions. Basic emotions are internal states generated by fundamental physical changes, which can then lead to genetically “hardwired” innate responses. They have been substantially preserved throughout evolution and share key functional and adaptive features across a broad phylogenetic range.

How do emotions work?

Our brain is covered in neural networks that become stronger or weaker as they are used. Those that are utilized repeatedly form very strong ‘neural highways,’ defining our default thinking, emotional profile, and personality. The good news is that neuroplasticity, the ability to modify brain connections, exists. (5). The interoceptive network in the brain constantly monitors your bodily sensations, such as your heartbeat, lungs filling and emptying, intestines operating, and stomach (slightly) aching. Your brain (encased in its dark, quiet cage known as the skull) attempts to decipher what these physiological feelings signify based on both information received from the outside world via your senses and past experience. (6). Each emotion has a distinct location in the brain. 

Three brain areas appear to be most closely associated with emotions: the amygdala, the insula or insular cortex, and the periaqueductal gray tissue in the midbrain. 

The amygdala, a paired, almond-shaped structure deep within the brain, integrates emotions, emotional behavior, and motivation. It interprets fear, distinguishes friends from opponents, and identifies social incentives and how to obtain them. The amygdala is also involved in classical conditioning, a sort of learning. According to Brainfacts: “The Anatomy of Emotions”, they talk about Russian biologist Ivan Pavlov, who in his experiments on digestion in dogs, initially described classical conditioning, in which a stimulus evokes a certain response through repeated exposure. When a lab technician offered them food, the dogs salivated. Over time, Pavlov saw that even when the technician was empty-handed, the dogs would start to salivate at his sheer presence. 

The insula is the source of distaste — a strong negative reaction to an unpleasant odor, for example. The sensation of revulsion may keep you from consuming poison or damaged food. When someone feels or expects pain, the insula lights up with activity, according to studies utilizing magnetic resonance imaging (MRI). According to neuroscientists, the insula receives a status report on the body’s physiological state and develops subjective feelings about it, hence connecting internal states, feelings, and conscious actions.

The periaqueductal gray, which is found in the brainstem, has also been linked to pain perception. It has receptors for pain-relieving substances such as morphine and oxycodone, and it can assist quiet activity in pain-sensing nerves, which may explain why you can occasionally distract yourself from pain so you don’t experience it as keenly. In addition to protective and reproductive activities, maternal bonding, and anxiety, the periaqueductal gray is involved in anxiety.

Together, these different parts of the brain, including the central and peripheral nervous system make up our vast sense of emotions.

How do emotions influence our daily life?

If you were asked what makes you human, emotions – or some component of your personality that is closely tied to emotions – could be near the top of the list. Our emotions have an impact on our relationships, our career, our lifestyle, our sense of ourselves, and our large and small decisions. Darwin was captivated by emotions and came to the conclusion that they exist to alert us quickly whether a situation is safe. Wrecognize the significance of our emotions in this and many other ways. We are aware that anger may be a source of strength, love keeps us connected to other people, and fear encourages us to cross the street carefully. However, we frequently have a tangled connection with our emotions, labeling some as positive and others as harmful. We may conceal and dismiss those we don’t want or consider ‘acceptable,’ while pursuing those we do, potentially to our cost. However, we frequently have a tangled connection with our emotions, labeling some as positive and others as harmful. We may conceal and dismiss those we don’t want or consider ‘acceptable,’ while pursuing those we do, potentially to our cost. Overall our emotions have a big influence on how we live our daily lives. You can be motivated to take action and have an impact on both major and minor life decisions by the feelings you encounter every day.

Akshaya Ganji, Youth Medical Journal 2022

References

  1. Project on the decade of the brain: “The Science of Emotion”-https://www.loc.gov/loc/brain/emotion/Damasio.html 
  2. Frontiers: “A Model for Basic Emotions Using Observations of Behavior in Drosophila”-https://www.frontiersin.org/articles/10.3389/fpsyg.2019.00781/full 
  3. Verywellmind: “Emotions and Types of Emotional Responses (The Three Key Elements That Make Up Emotion)”-https://www.verywellmind.com/what-are-emotions-2795178 
  4. Hockenbury D. Hockenbury SE. Discovering Psychology. Worth Publishers 
  5. Welldoing: “The Neuroscience of Emotions”- https://welldoing.org/article/neuroscience-emotions 
  6. Behavioral Research Blog: “How emotions are made” –https://www.noldus.com/blog/how-emotions-are-made 
  7. Brainfacts: “The Anatomy of Emotions”-https://www.brainfacts.org/thinking-sensing-and-behaving/emotions-stress-and-anxiety/2018/the-anatomy-of-emotions-090618 
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Commentary

Exploring The Nervous System

The Nervous System is the body’s internal communication system. These sensory cues are interpreted by the brain to understand what is going on outside and inside the body. Without the Nervous System, we would never understand what’s going on.

Introduction

Your nervous system serves as the command center for your body. It is controlled by your brain and governs your emotions, thoughts, and automatic responses to the environment around you. Almost all of what you think, feel, say, and do is controlled by your nervous system. It manages complex functions like memory, cognition, and movement. Furthermore, it is crucial for bodily functions like breathing, blushing, and blinking that occur automatically. It regulates other bodily functions and systems, including digestion, breathing, and sexual development (puberty). Your nervous system can be harmed by diseases, accidents, pollutants, and the natural aging process. The nervous system is split into two parts. Each component comprises billions of neurons, also known as nerve cells. These unique cells communicate with your body by sending and receiving electrical impulses. The main divisions of the Nervous System are the Central Nervous System (CNS), and the Peripheral nervous system, which then is further organized into other systems. (1)

What does the Nervous System do?

A nerve cell, or neuron, is the basic unit of the neurological system. The human brain has about 100 billion neurons. A neuron has a cell body, which contains the nucleus, as well as unique extensions known as axons (pronounced AK-sonz) and dendrites (pronounced DEN-drahytz). Nerves are bundles of axons found throughout the body. Neurons can interact across extended distances thanks to axons and dendrites. (2). When a neuron transmits a message to another neuron, it sends an electrical signal down the length of its axon. At the end of the axon, the electrical signal changes into a chemical signal. The chemical signal is then released by the axon via chemical messengers known as neurotransmitters (pronounced noor-oh-TRANS-mit-erz) into the synapse (pronounced SIN-aps)—the gap between the end of an axon and the tip of a dendrite from another neuron. The neurotransmitters carry the signal across the synapse to the adjoining dendrite, where it is converted back into an electrical signal. The electrical signal is subsequently transmitted across the neuron and through the same conversion steps as it travels to neighboring neurons.  

The nervous system also consists of glia, or non-neurons, cells (pronounced GLEE-uh). Glial cells provide a variety of critical activities that keep the nervous system running smoothly. To send impulses or messages throughout your body, the nervous system employs neurons. These electrical signals go through your body, connecting your brain, skin, organs, glands, and muscles. The messages assist you in moving your limbs and sensing sensations such as discomfort. Your eyes, hearing, tongue, nose, and nerves throughout your body gather information about your surroundings. The data is then transmitted to and from your brain via nerves. Neurons of various types send out messages in various ways. 

Image 1: Sciencefacts

The Different Parts of the Nervous System

The Nervous System is divided into two main parts. The Central Nervous System, which comprises the brain and the spinal cord, and the Peripheral Nervous System, which is made up of all the body’s parts that are connected by nerves that emerge from the spinal cord. The Peripheral Nervous System is then divided into Sensory Division and the Motor Division. The Motor Division is then organized into the Somatic and Autonomic Nervous System. The Autonomic Nervous system is then finally composed of the Sympathetic and Parasympathetic Divisions. 

Central Nervous System (CNS)

The brain and spinal cord contain the central nervous system (CNS). The central nervous system is the processing center of the body. The brain is in charge of the majority of the body’s operations, including awareness, movement, thinking, speaking, and the five senses of seeing, hearing, feeling, taste, and smelling. 

The spinal cord is a brain addition. Through the network of peripheral nerves that link to it, it transmits and receives messages to and from the brain. (3)

Peripheral Nervous System (PNS)

Your peripheral nervous system is everything else, and it includes nerves that flow from your spinal cord and brain to feed your face and the rest of your body. The term “peripheral” is derived from the Greek phrase for “around or outside the center.”

The peripheral nervous system (PNS) is the part of your nervous system that is not directly connected to your brain or spinal cord. It is responsible for both transmitting information from various sections of your body back to your brain and carrying out commands from your brain to various parts of your body. Some of these signals are automatic, such as those to your heart and gut. Others, such as those that control locomotion, are under your command. (4) 

Image 2: Cleveland Clinic

Sensory Division

The afferent division, also known as the sensory division, transfers impulses from peripheral organs to the CNS.

Motor Division

The efferent or motor division sends impulses from the CNS to the peripheral organs in order to produce an effect or action.

Somatic Nervous System (SNS)

The peripheral nervous system includes the SNS, which is connected with the voluntary control of body movements through the use of skeletal muscles. (6). The somatic nervous system’s primary roles are to transport sensory information from nerves to the central nervous system and to transport motor information from the central nervous system to muscles via motor neural pathways to govern their activity. The sensory-somatic nervous system is made up of cranial and spinal nerves, whereas the autonomic nervous system is made up of sensory and motor neurons that connect the CNS to the internal organs.

  Autonomic Nervous System (ANS)

The autonomic nervous system is the part of your nervous system that controls automatic actions such as heartbeat and blood vessel widening or narrowing. When something goes wrong in this system, it can lead to major complications, such as high blood pressure. (5)

Sympathetic Nervous System (SNS)

Your autonomic nervous system is made up your sympathetic nervous system. It could be referred to as your “automatic” nervous system because it controls numerous functions that you do not have to think about. This includes, among other things, controlling your heart rate, blood pressure, digestion, urination, and sweating. Your sympathetic nervous system is most known for its role in responding to risky or stressful conditions. In certain conditions, your sympathetic nervous system acts to increase your heart rate, provide more blood to places of your body that require more oxygen, or perform other actions to assist you in escaping danger. 

The majority of the impulses sent by your sympathetic nervous system originate in your spinal cord. The signals exit the spinal cord and trigger structures known as ganglia. Your sympathetic ganglia then sends the required signals to various sections of your body. Your heart, lungs, arteries, sweat glands, and digestive system could all be affected.

Your “fight-or-flight” response is controlled by your sympathetic nervous system. Danger or stress triggers your sympathetic nervous system, which can result in a variety of physiological reactions. In response to a threat or stress. These impacts assist you in situations where you must think or act swiftly. They enhance your vision, reflexes, endurance, and strength. Your sympathetic nervous system also activates when your body is under stress, such as when you exercise or are unwell. 

Your sympathetic nervous system activity influences your immune system and the repair processes in your body. If you get harmed, these impacts can assist your body start healing faster. To communicate, your sympathetic nervous system employs molecules known as neurotransmitters. These substances are norepinephrine, epinephrine, and acetylcholine. (7)

Parasympathetic Nervous System (PNS)

The parasympathetic nervous system balances your sympathetic nervous system. While your sympathetic nervous system is in charge of your body’s “fight or flight” response, your parasympathetic nervous system is in charge of your body’s response when you are at rest. The primary function of the parasympathetic nervous system is to calm down or lessen your body’s activity. Because of the signals it sends, the rhyming phrases “rest and digest” or “feed and breed” are simple ways to recall what your parasympathetic nervous system performs.

Your parasympathetic nervous system is one of two parts of your autonomic nervous system. Your autonomic nervous system is a subsystem of your peripheral nervous system, which is all the nervous tissue in your body excluding your brain and spinal cord.

Your parasympathetic nervous system uses four of your 12 cranial nerves. These are nerves that connect directly to your brain. (8)

Image 3: Merck Manuals.

In the end, all these subsystems make up our Nervous System.

Akshaya Ganji, Youth Medical Journal 2022

References

  1. Cleveland Clinic: “Nervous System”- https://my.clevelandclinic.org/health/articles/21202-nervous-system 
  2. NIH: “What are the parts of the nervous system?” – https://www.nichd.nih.gov/health/topics/neuro/conditioninfo/parts 
  3. Healthdirect: “Central nervous system (CNS)- https://www.healthdirect.gov.au/central-nervous-system 
  4. Cleveland Clinic: “Peripheral Nervous System (PNS)- https://my.clevelandclinic.org/health/body/23123-peripheral-nervous-system-pns 
  5. MedicinePlus: Autonomic Nervous System Disorders- https://medlineplus.gov/autonomicnervoussystemdisorders.html 
  6. National Library of Medicine: Neuroanatomy, Somatic Nervous System- https://www.ncbi.nlm.nih.gov/books/NBK556027/ 
  7. Cleveland Clinic: Sympathetic Nervous System (SNS)- https://my.clevelandclinic.org/health/body/23262-sympathetic-nervous-system-sns-fight-or-flight 
  8. Cleveland Clinic: Parasympathetic Nervous System (PSNS)- https://my.clevelandclinic.org/health/body/23266-parasympathetic-nervous-system-psns 
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Health and Disease Neuroscience

Anxiety Disorder: Exploring The Reality Behind Having Anxiety

Anxiety. A term that is used so frequently that it lost its meaning. This article covers the biology of the illness, how it is processed in the brain, its influences on individuals and the various diagnosis and treatment. 

Introduction

Experiencing anxiety or feeling anxiousness is a part of life. However, people suffering from anxiety disorders usually experience severe, excessive, and persistent worry and fear about ordinary events. These uncomfortable, hard to regulate, out-of-proportion to the real threat, and protracted sensations of worry and panic interfere with daily activities. According to the American Psychiatric Association entitled “What are Anxiety Disorders?” (1),  Anxiety is a typical response to stress and in some circumstances, it can be beneficial. It can alert us about potential threats and assist with planning and attention. Anxiety disorders are distinguished from typical sensations of nervousness or anxiety by the presence of excessive fear or anxiety. According to the Nami National Alliance on Mental Illness, titled, “Anxiety Disorders”(2),  they stated that “ Anxiety disorders are the most common type of mental illness in the United States. In the US, approximately 40 million persons (19.1%) suffer from an anxiety illness. Meanwhile, approximately 7% of children aged 3-17 experience issues with anxiety each year, and most people develop symptoms before age 21.”

 To add on, there are 5 major types of Anxiety. Generalized Anxiety Disorder, Obsessive-Compulsive Disorder (OCD), Panic Disorder, Post-Traumatic Stress Disorder (PTSD), and Social Phobia (or Social Anxiety Disorder). 

What causes Anxiety Disorder?

Having Anxiety Disorder interferes with daily activities and is difficult to control. And so, what is the cause? The specific cause of anxiety disorders is unknown to researchers. Although, throughout examination, researchers have found that there are various causes of Anxiety Disorder, and each is based on its different types. 

It can be caused by genetics, since Anxiety Disorders may run in families. There could be environmental stress, such as childhood abuse and neglect, the death of a loved one, and several other traumatic situations. Anxiety Disorders can be caused with drug abuse or withdrawal. Some anxiety symptoms may be concealed or reduced with specific medications, and so alcohol and drug abuse can go hand in hand with anxiety disorders. Some heart, lung, and thyroid diseases can exacerbate or induce symptoms that are similar to those of anxiety disorders. (4)

According to several studies, dysfunctional brain circuits that regulate emotions and fear may be responsible for anxiety disorders. They are characterized by a variety of neuroendocrine, neurotransmitters, and neuroanatomical abnormalities. The great degree of interconnectedness between neurotransmitter- and neuropeptide-containing circuits in limbic, brain stem, and higher cortical brain areas complicates identifying the most functionally significant differences. Additionally, environmental events and underlying genetic predisposition may lead to a primary alteration in brain structure or function or in neurotransmitter signaling; such abnormalities might raise the risk for psychopathology. (3)

To continue, it’s important to consider the neurotransmitters that allow communication between different regions. When there is an increased activity in the limbic system and various emotion-processing brain regions, patients who have Anxiety Disorder could have a decrease in inhibitory signals by by γ-amino-butyric-acid (GABA) or increased excitatory neurotransmission by glutamate. Each anxiety disorder, as well as major depressive disorder (MDD), is vulnerable due to both genetic and environmental factors.

Overall, Anxiety is produced by an imbalance in the brain chemicals serotonin and noradrenaline, which are important in mood regulation; a combination of past trauma such as assault, abuse, or bullying; chronic pain condition; or inherited causes, among other things. The decision to identify MDD, PD, PTSD, SAD, and GAD as different illnesses must be established on pathophysiology, genetics, duration of illness, and treatment response data, in addition to clinical phenomenology. The variations in neuroendocrine, neurotransmitter, and neuroanatomical functions between individuals with mood or anxiety disorders and healthy control subjects must be evaluated with caution (Table 3). Brain areas and neurotransmitter systems associated in mood and anxiety disorders perform a variety of activities, many of which are unrelated to the etiology of psychiatric diseases. (3)

Figure 1: Pearson: “Structures under the Cortex: The Limbic 

System”

Figure 2: National Library of Medicine: “The Neurobiology of Anxiety Disorders: Brain Imaging, Genetics, and Psychoneuroendocrinology.”

Symptoms of Anxiety

The primary symptoms of Anxiety prevail of 

  • panic
  • uneasiness
  • hyperventilation
  •  tense muscles
  •  rumination
  • fervently avoiding dreaded things or locations
  • Having an increased heart rate
  • Sweating
  • Feeling weak 
  • difficulty focusing or thinking about anything but the current issue 
  • Having digestive issues 
  • having trouble managing worry 
  • a desire to stay away from things that make you anxious

How Anxiety affects individuals

An anxiety-inducing scenario or impending event is a typical physical response to stress. This reaction starts in the Amygdala, a part of the brain that sends distress signals to the hypothalamus. (Fig 1).  The remainder of the body receives these signals, which triggers a “fight or flight” reaction. A short-term, physiologically positive stress reaction occurs when the adrenaline hormone, an elevated heart rate, increased blood supply to the brain, and the ensuing surge of oxygen compel us to focus on the issue and find a solution. However, long-term repetitive stress reactions to anxiety, excessive worry, and a variety of day-to-day concerns. There are 5 major types of Anxiety and each type affects the individual differently.

Generalised Anxiety Disorder (GAD)

With GAD, you experience excessive, unreasonable tension and concern for little to no reason. You worry excessively about most everyday circumstances and can’t recall the last time you felt calm and collected. This constant stress and tension may be accompanied by bodily symptoms such as restlessness, feeling on edge or quickly fatigued, difficulties concentrating, muscle strain, or sleeping issues. Worries about ordinary things such as job duties, family health, or minor issues such as chores, car maintenance, or appointments are common. (1)

Obsessive-Compulsive Disorder (OCD)

OCD can induce obsessive, intrusive thoughts that can be stressful, as well as an overpowering desire or compulsion to execute a routine repeatedly. This could be shown in his or her behaviors, such as cleaning or washing hands excessively, putting goods in a drawer in a specific way, folding away clothes, and so on. (5)

Panic Disorder

Panic Disorder involves recurrent episodes of abrupt, severe feelings of worry, fear, or terror that peak in just a few minutes (panic attacks). You might experience dread, breathlessness, chest pain, or a rapid, fluttering, or hammering heart (heart palpitations). These episodes don’t coincide with a recognized phobia or stressor; instead, they happen “out of the blue.” (7), and so these panic attacks might lead you to worry about them happening again or to avoid circumstances where they have happened.

Post-Traumatic Stress Disorder (PTSD)

PTSD is a psychiatric disease that can arise in people who have encountered or witnessed a traumatic event such as a natural catastrophe, a catastrophic accident, a terrorist attack, war/combat, or rape, or who have been threatened with death, sexual violence, or serious injury. People suffering from PTSD have powerful, unsettling thoughts and sensations about their experience that remain long after the traumatic event has finished. They may relive the event in flashbacks or dreams, experience sadness, dread, or fury, and feel disconnected or estranged from others. Persons suffering from PTSD may avoid circumstances or people that remind them of the traumatic experience, and they may have significant unpleasant reactions to seemingly innocuous things such as a loud noise or an unintentional touch. (6)

A traumatic incident must have occurred in order for PTSD to be diagnosed. The exposure, however, may be indirect rather than direct. A person who sees the violent death of a close family member or friend, for example, may develop PTSD. Some of the many symptoms and diagnosis of PTSD include Intrusive thoughts, resisting reminders of the traumatic event, changes in cognition and personality, and changes in arousal and reactivity. (6)

Social Phobia (Social Anxiety Disorder)

Social anxiety disorder (social phobia) is characterized by intense anxiety, fear, and avoidance of social interactions as a result of emotions of humiliation, self-consciousness, and concern about being judged or seen adversely by others.

Risk factors

Anxiety disorders are caused by a variety of reasons, including genetic, environmental, psychological, and developmental factors. Anxiety disorders can run in families, implying that the diseases are caused by a mix of genes and environmental factors. (1). A few factors are, 

  • Truma
  • Stress from an illness
  • Other mental health disorders 
  • Drug or alcohol 
  • And many others.

Diagnosis and Treatment

The first step is to see your doctor to ensure that there is no physical problem causing the symptoms. If you are diagnosed with an anxiety disorder, a mental health expert can help you find the appropriate treatment. Unfortunately, many people suffering from anxiety problems do not seek treatment; they are usually unaware that they are suffering from a disease. Although each anxiety condition is distinct, the majority respond effectively to two methods of treatment: psychotherapy (often known as “talk therapy”) and medicines. These treatments can be administered individually or in combination. 

Psychotherapy, often known as talk therapy or psychological counseling, entails working with a therapist to minimize your anxiety symptoms. It might work well as an anxiety therapy. 

The most effective type of psychotherapy for anxiety problems is cognitive behavioral therapy (CBT). CBT is a short-term treatment that focuses on teaching you how to think, react, and behave differently in order to feel less nervous. There are particular strategies to help you improve your symptoms and gradually return to the activities you’ve avoided due to anxiety. 

CBT incorporates exposure treatment, in which you gradually expose yourself to the object or event that causes your anxiety in order to gain confidence in your ability to manage the situation and anxiety symptoms. (8)

 Although medications will not cure anxiety disorders, depending on the type of anxiety disorder you have and whether you also have other physical or mental health problems, they can provide significant relief from symptoms. The most often given drugs are antidepressants and anti-anxiety meds, which are typically only provided temporarily.

In some cases, your doctor may prescribe other medications, such as sedatives, often known as benzodiazepines, or beta-blockers, which are commonly used to treat cardiac issues, are also used to treat physical symptoms of anxiety. These drugs are meant for short-term alleviation of anxiety symptoms and should not be used indefinitely. (8)

Self-Help, Coping, and Managing

People can also do a variety of things to help cope with the symptoms of anxiety disorders and make treatment more successful. Meditation and stress-reduction methods can be beneficial. They can join support groups (in person or online) that can allow people to share their experiences and coping mechanisms. They can learn more about the nuances of a disorder and assist family and friends in better understanding the condition can also be beneficial. To include, caffeine, which can aggravate symptoms, should be avoided, and any drugs should be discussed with your doctor.

Akshaya Ganji, Youth Medical Journal 2022

 References 

  1. American Psychiatric Association: “What are Anxiety Disorders?”-https://psychiatry.org/patients-families/anxiety-disorders/what-are-anxiety-disorders
  2. Nami National Alliance on Mental Illness: “Anxiety Disorders”-https://www.nami.org/About-Mental-Illness/Mental-Health-Conditions/Anxiety-Disorders 
  3. National Library of Medicine: “The Neurobiology of Anxiety Disorders: Brain Imaging, Genetics, and Psychoneuroendocrinology.”-https://www.mayoclinic.org/diseases-conditions/anxiety/symptoms-causes/syc-20350961 
  4. WbMD: “Anxiety Disorders”-https://www.webmd.com/anxiety-panic/guide/anxiety-disorders 
  5. MayoClinic: “Anxiety Disorders”-https://www.mayoclinic.org/diseases-conditions/anxiety/symptoms-causes/syc-20350961 
  6. American Psychiatric Association: “What is Posttraumatic Stress Disorder (PTSD)?”-https://psychiatry.org/patients-families/ptsd/what-is-ptsd 
  7. National Institute of Mental Health: “Panic Disorder”-https://www.nimh.nih.gov/health/statistics/panic-disorder 
  8. MayoClinic: “Anxiety Disorders (Dignonis)-https://www.mayoclinic.org/diseases-conditions/anxiety/diagnosis-treatment/drc-20350967