BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: neurons

“Walk It Off”: How Your Coach’s Most Annoying Phrase Might Just Save Your Brain

We all know that regular exercise keeps our bodies strong, but what if it could help keep our memories sharp, too? According to a new study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, researchers at UC San Diego and Wake Forest University found that both low and moderate-high intensity exercise can slow cognitive decline in older adults at risk for Alzheimer’s disease. 

Brain Exercising

The study, called EXERT, tracked nearly 300 sedentary older adults with amnestic mild cognitive impairment (aMCI), a condition marked by memory problems that don’t yet interfere severely with daily life, but often lead to Alzheimer’s. About 16% of people with aMCI progress to Alzheimer’s each year. Participants were assigned to either a moderate-to-high intensity aerobic group or a low-intensity stretching and balance group. Each person exercised three to four times per week at a local YMCA, under supervision, for 12 months. What’s remarkable is that cognitive function remained stable in both exercise groups over the year, whereas cognitive decline is usually expected in this population. Additionally, participants showed less brain volume loss, especially in the prefrontal cortex, a key region involved in decision-making, attention, and memory, compared to individuals who only received standard care like regular check-ups and medications.

What makes this study stand out is its accessibility. The team partnered with local YMCAs to bring the interventions into community settings, showing that effective brain health treatments don’t have to involve fancy equipment or extreme intensity. Other researchers have come to many similar conclusions. Researchers at Harvard Medical School tackled the question: Which exercise is best for your brain? This article concluded, “forms of aerobic exercise that get your heart pumping might likely yield the best benefits,” says Dr. Scott McGinnis, assistant professor of neurology at Harvard Medical School.

So, how does this connect to what we’ve learned in AP Biology? This connects to neural networks, which are incredibly complex webs of interconnected neurons that process and transmit information through electrical and chemical signals. When a neuron receives a stimulus, like a signal from another neuron or the environment, it fires an action potential, an electrical impulse that travels down its axon. This triggers the release of neurotransmitters like glutamate or acetylcholine into the synapse, which then bind to receptors on the next neuron, continuing the message. These transmissions are what allow you to think, remember, and even move. Exercise helps maintain the health of this communication system in several ways. First, regular movement increases blood flow to the brain, delivering more oxygen and glucose, which neurons need for aerobic respiration, and more ATP means more power for the sodium-potassium pumps that reset the neuron after firing. Without that pump, your neurons can’t keep firing signals. We’ve talked in class about how stimuli are detected and translated into neural responses, and how neurons relay messages using action potentials and neurotransmitters. This study is a real-world example of that biology in action. Exercise acts as both a stimulus and a support system for the neural pathways that keep our brains functioning. It doesn’t just make you feel better, it keeps your neurons alive and talking.

I chose this topic because the science behind memory and cognition fascinates me, especially knowing that there’s something we can do to protect our minds. It’s hopeful. With Alzheimer’s affecting so many families, the idea that something as accessible as regular walking or stretching could delay or prevent decline is powerful.

Here’s a question for you: Would you commit to 30 minutes of light exercise a day if it meant possibly protecting your brain health? Why or why not? Let me know in the comments—I’d love to hear your thoughts.



Telemedicine Yay or Nay?

In class, we learned about neurons and their function. Neurons carry messages all through out our body. They are reason we feel pain among many other things. When we are exposed to a given stimuli–sound, taste, or other sensation–the dendrites of our neurons will receive the stimuli. The signal will then make its way down the axon of the neuron. Eventually, the stimuli will come to the synapse terminals. Here, vesicles with neurotransmitters with undergo simple diffusion over the synaptic cleft. The neurotransmitters will bind with the ligand gated ion channels of the dendrites of the next neuron and the process will repeat until the single has reached its area of interest.

This simple process can be the cause of so much anguish. Take Kent Manuel, who has been training to be able to re-use his legs after a paralysis surgery. Neurons explain, from a broad sense, why he has trouble walking. The nerve cells relaying information from his legs to his brain, and vice versa, have been damaged to the point where they can no longer carry out their function.

However, there is some optimism for Mr. Manuel. He was recommended to undergo palliative care–one on one interaction that helps patients with great discomfort. Palliative care helps one with physical, mental, and spiritual issues. Interestingly, Mr. Manuel’s doctor, Julia Frydman, lives hundreds of miles away from him. The two were able to communicate via virtual calls in what has become known as telemedicine.

Unfortunately, this new form of medicare may not last past march 1st of this year. Although the Republicans in Congress were willing to increase the cost of medicare as whole to accommodate for telemedicine, it is unlikely to survive for long. The Republicans voted down the motion when President Donald Trump and Tesla CEO Elon Musk spoke out against it. Regardless, telemedicine is here to stay until March.

Telemedicine is a very practical new tool. Many doctors visits revolve solely around doctor patient conversation (eg. talking over results). Thus, the need to actually be in an office is pointless. In addition, if fewer people are entering the ER for test results among other things than the people who are in urgent need of aid will be seen sooner.

That being said there are some cons to telemedicine. As a whole, many of the services health care professionals provide need to be done in person (eg. vaccinations, drawing blood, getting a cast on). Furthermore, a recent study in a New York Times article mentioned that 40% of those involved in the study had telemedicine and did not find it effective.

I personally think I hybrid approach would be most effective, but what do you think?

Scientists Have Traced all 54.5 Million Connections in a Fruit Fly’s Brain

Scientists have accomplished a remarkable feat by creating the first comprehensive map of a fruit fly’s brain, or “connectome,” containing information on all 139,255 neurons and their 54.5 million connections. The brain of Drosophila melanogaster, a creature small enough to fit its brain into the size of a poppy seed yet complex enough to provide new insights into brain function, is shown in this map as it transmits neuronal information throughout the brain. More than 149 meters of brain wiring are shown on the map.

Connectome

This enormous study, which took almost 20 years to complete, used machine learning to map the complex neuronal pathways and complicated electron microscopy to examine over 7,000 thin slices of a female fruit fly’s brain. Nevertheless, human skill was still required to guarantee accuracy and fix mistakes.

The map was proofread by hundreds of people and more than fifty laboratories. Given the intricacy of neuronal connections, the experiment, which was led by researchers at Princeton University and the Allen Institute for Brain Science, required meticulous attention to detail.

Significant discoveries have already resulted from the project. For example, the entire fly’s eye is covered by just two CT1 neurons, each of which makes about 148,000 synapses and is involved in motion and light detection. Another discovery revealed that certain neurons function as “integrators,” taking in information from a large number of other neurons, while other neurons work as “broadcasters,” dispersing messages across the brain. These patterns shed more light on the information dispersion process in neural networks.

The connectome also makes it possible to build computer models that, using these connections as a foundation, mimic brain activity. To show how this map can imitate and anticipate brain processes, scientists have already started modeling the effects of taste neurons on other brain regions.

In addition to being a significant accomplishment for insect neuroscience, the mapping of the fruit fly’s brain provides a preview of what lies ahead for more sophisticated creatures like mice and humans. By building more thorough connectomes, scientists expect to provide important insights into how brain wiring affects behavior, if individual differences exist in connectomes, and how these connections might change over time.

This study is related to AP Biology, as it revealed that certain neurons function as “integrators” or “broadcasters,” taking in or dispersing messages across the brain. We learned that neurons communicate with one another through the flow of chemicals(ions) in and out of the plasma membrane of the cell. When an impulse is received, Na+ channels open and Na+ flows in by facilitated diffusion. However, this causes a more positive charge on the inside of the neuron, so K+ flows out through channels, so it is once again more positive on the outside.  This process is a vital part of the discovery, as it explains the ways neurons communicate with each other to integrate or broadcast information. 

This study is particularly fascinating to me, as I am intrigued by neuroscience and hope to study it in college! I think this connectome will lead to excellent scientific development! What do you think? Comment and share!

How COVID-19 Robs Us of Our Sense of Smell

Led by researchers from NYU Grossman School of Medicine and Columbia University, the study with the pandemic virus, SARS-CoV-2, found that the infection caused by SARS indirectly dials down the action of olfactory receptors (OR), proteins on the surfaces of nerve cells in the nose that detect the molecules associated with odors. This new study not only sheds light on the reason for loss of smell, but also sheds light on the effects of Covid-19 on other types of brain cells, and on other lingering neurological effects of COVID-19 like “brain fog”, headaches, and depression.SARS-CoV-2 without background

The study involved analysis of olfactory tissue from human autopsies and experiments on golden hamsters, a species highly reliant on their sense of smell. The researchers observed that the virus triggers an increase of immune cells, which release cytokines altering the genetic activity of olfactory nerve cells. They suggest that that if olfactory gene expression ceases every time the immune system responds in certain ways that disrupts interchromosomal contacts, then the lost of sense of smell may act as an early signal that the COVID-19 virus is damaging brain tissue before other symptoms presents, and suggest new ways to treat it. However, these cells are not infected by the virus directly. These findings could have broader implications than it first seems. The persistence of immune reactions in the nasal cavity may influence cognitive functions and emotions because these olfactory neurons are connected to sensitive brain regions. The team’s next steps include creating treatments to protect the “nuclear architecture” of these cells and prevent long-lasting implications. This study aligns with many core topics in AP Biology, such as proteins, the immune system’s role in disease response, and the immune system’s interaction with neurons. It offers insight into the understanding of how cells communicate and respond to pathogens. It also delves into gene expression which illustrates how factors like viral infections can lead to changes in a cell’s genetic activity. This study represented a significant step in understanding the broader effects of COVID-19 and opens options for new treatment strategies. The Study also provides valuable insights into the functions of the immune system and neurons during a COVID-19 infection. The increase of immune cells and the release of cytokines in response to SARS-CoV-2 can alter the activity of olfactory nerve cells. This not only affects our sense of smell but also has more affects on brain function. The immune reaction in the nasal cavity could impact cognitive functions and emotional states because of the connection of olfactory neurons to sensitive brain regions. This understanding of how COVID-19 effects immune responses and neuronal changes is crucial as it helps scientists find new ways for treating the long term effects of COVID-19. Now this brings the question of if this study gives insight into how to treat patients with long term issues from Covid and how they will be treated.

 

3300 Strains of Cells?

21 papers published on October 12th 2023, have revealed there is more to the brain than previously known. 3300 types of brain cells, a magnitude greater than previous reports, were discovered with the help of the Brain Atlas, a $375 million effort started in 2017. These new discoveries were made possible by new technologies that allowed scientists to probe millions of human brain cells with biopsied tissue or cadavers. This discovery is just the beginning, though, as these discoveries only sampled a small fraction of the 170 billion cells in the human brain. The process of obtaining the cells was lengthy and required several sources such as people who had recently passed away and those undergoing brain surgery.  Scientists attached glass tubes to each cell to inspect their electrical activity, injected dye to make their structure visible, then extracted the nuclei from the cells. Although this new discovery provides an astonishing amount of new data, the amount of cells discovered is only a fraction of the total number of cells within our brains so there could be up to 3300 more types of cells that we have yet to discover.

Mouse brain cells

An article published only two days after the one described above looks further into the 3300 cells types. The article identifies that the cells can be grouped into 461 clusters. In addition, new brain cells were found inside the cerebral cortex, the region of the brain responsible for memory, and language. Furthermore, an article published on the same day claims that neuron cells, responsible for transmitting stimuli, were present alongside the new cells in the samples they received. The article then identifies that from the cells obtained, half were neuronal cells and half were not.

Neurons, identified in half of the new cells, are the fundamental parts of the brain and nervous system. Our most recent topic in AP Biology is neurons and their functions. Neurons have many functions such as receiving sensory input from the external world, sending commands to the muscles, and transforming the electrical signals sent out during this process. The appearance of a neuron consists of three parts: dendrites, an axon, and a soma which can appear like a tree without leaves. Neurons are located all throughout the brain, with 10-20 billion in the cerebral cortex and 55-70 billion in the cerebellum (wikipedia) so it is not surprising that so many were identified in the new cells. Neuron cells are similar to eukaryotic cells in some ways, but not all. Like eukaryotes, they have a cell body that contains organelles. On the other hand, neurons have two branch structures, axons and dendrites, that differentiate them from a typical cell

Although the recent discovery of 3300 new types of brain cells is an astounding advancement in the ongoing research of the brain, this discovery is only a small portion of what lies within the large, independent system, that is our brain. How many cell varieties do you think are still undiscovered? I say hundreds.

 

 

 

 

 

Unlock the POV of Pups: How Dogs See the World Beyond Colors.

Madsen the dog, 001

Have you ever wondered how your furry friends recognize the world around them? This question was asked by a group of scientists who recently studied how canines “see” the world not only with their eyes, but also with their nose.

For a long time, the world believed that dogs could only see the world in black and white, or that dogs could only perceive color weakly, if at all. However, this myth was debunked in 1989 by ophthalmologist Jay Neitz and his colleagues, who discovered that dogs can indeed see colors, specifically blues and yellows. They cannot perceive reds and greens, similar to color-blind human.
Assorted Red and Green Apples (deuteranope view)

The reason why dogs can’t process light as well as most human is because they only have two types of color-sensing receptors, called cones, in their retinas, similar to many mammals: cats, pigs, and raccoons. This differentiates them from humans which have three cones. In addition, most dogs have 20/75 vision, meaning that they need to be 2o feet away to see as clear as a human would from 75 feet. Their world may be somewhat blurry compared to ours.

To truly understand how dogs see the world, we must look beyond their ability to process color, as highlighted by Sarah-Elizabeth Byosiere. Dogs rely on various other senses to help them “see,” or identify objects and movements around them. For example, unlike humans who have difficulty seeing in dark environments, dogs’ eyes are made to see in both daytime and nighttime. This is because of their abundance of rods, a type of photoreceptor cell in the retinas, which aids in night vision. Rods are 500-1000 times more sensitive to light than cones which allows dogs to see better in the dark. Dogs also have a unique structure in their eyes called the Tapetum Lucidum(Shown in diagram below), which acts like a mirror that reflects light back onto the retina. This enables them to see in conditions with six times less light than what human requires to see.

This is also the reason why dogs’ eyes will glow in photos in the dark, because their Tapetum Lucidum reflects the light back.

(Structure of eyes)

Mammal eye structure (tapetum lucidum)

Another significant aspect of dogs’ perception is their sense of smell, they are 10,000 to 100,000 times stronger than that of an average human. Dog’s mighty sense of smell plays a crucial role in how they perceive the world, they can even pick up odors from as far as 12 miles. Another study published recently in the Journal of Neuroscience revealed a direct connection between dogs’ olfactory bulb, which processes smell, and their occipital lobe, which processes vision. This integration of sight and smell was not observed to happen on any of other animal species.

While human are good at recognizing different colors, dogs are more into their sense of smell that humans can’t appreciate. Dogs aren’t missing out on anything; they just have their own unique way of exploring the world around them.

In AP Biology, we learned about how neurons transmit signal to the brain when we touch, hear, see, and smell. When vision and smell is received by optic nerve in eyes and olfactory sensory neurons in noses, they will pass the information of the sight and smell to the brain through neurons. Neurons transmit signals simply through a flow of ions across the axon membrane, which reverses the distribution of charges of the neuron compared to when it is at rest. This is how a neuron passes a signal to another neuron, they will repeat this process until they reach the occipital lobe and olfactory bulb in the brain where the information of the sight and smell will be processed and analyzed.

As a biology student, I have always wondered about how canines, mankind’s best friend, and how other animals see the world in their perspective. It is fascinating to find out that all animals have their unique way of sensing the world and collecting information from the area around them. Their “sensing” strategy are often different from ours’s; human primarily uses vision to receive information of the world, but our neighbors on earth could be using their sense of smell, sense of hearing, and even echoing to accomplish the same goal! Let me know in the comments below if you are also curious about how other animals recognize our world or if you are interested in this topic! Share your thoughts with me! If you want further information about this post or on this topic in general, please go to ScientificAmerican.com for more information and further research.

Newly Discovered Neurons and Their Role in Maintaining Normal Body Temperature

The internal body temperature in humans and mammals is maintained at 37℃/96℉, unless disrupted by a force like an illness or heat exhaustion. Regulating the body to stay in the normal range is crucial for survival and for enzyme function.  Our internal body temperature is constantly being regulated by our hypothalamus, located at the base of our brain. The hypothalamus uses sensors from a mediator known as prostaglandin E which is brought about when an infection is present in the body. After PGE2 is present, it signals for the body to raise its temperature and combat the infection. If temperature levels are abnormal, the enzymes in our body have trouble functioning because they need specific temperature conditions to carry out reactions. Therefore, maintaining homeostasis throughout the body by regulating internal temperature is key to human survival.

Prostaglandin E

A team of researchers at Nagoya University in Japan were inspired by this process and decided to focus on the unknown neurons that make up the receptors of PGE2 and how this regulation process functions. The group of professors and colleagues successfully discovered key neurons that work to regulate the body temperature of mammals. This finding can be highly useful for creating future technology that can artificially fix body temperature related conditions such as hypothermia, heat stroke, and obesity.  

Neuron

Neuron

By using rats as a subject for their research, they exposed the rats to cold (4°C), room (24°C) and hot (36°C) temperatures to observe the effect of temperature changes on EP3 neuron response. After conducting the experiment, the researchers were able to conclude that exposure to the hot temperature led to an activation of EP3 neurons and the cold temperatures did not. Once they made this conclusion, they dug deeper into the neurons and analyzed the nerve fibers of the neurons to discover where the signal transmission occurs after sensing an infection. The researchers were able to conclude that the neuron fibers are spread out in different areas of the brain, mainly the dosomedial hypothalmus, which works to activate the sympathetic nervous system. Not only did they discover these fibers, but they also discovered the substance that EP3 neurons utilize to send signals to DMH. By observing the structure and chemical makeup, they found that this substance is a neurotransmitter known as gamma-aminobutyric acid (GABA), which inhibits neuron excitation. 

Finally, their findings support the idea that EP3 neurons are a major component of regulating internal body temperature and that they send out the GABA substance to signal to DMH neurons for a proper response. Their research proves that intiating a neural response decreases body temperature and inhibiting neurons leads to an increase in body temperature. Furthermore, their strong research in this area can support future development of advanced technology that will be capable of artificially adjusting internal body temperature. The anticipated technology could help prevent hypothermia, treat obesity to keep body temperature slightly higher and initiate fat burning, and be a key method of survival in hot environments. 

 

Environmental Cues Can Trigger Planned Movement and Advance Studies of Motor Disorders

A group of scientists from different universities, including Dr. Hidehiko Inagaki, Dr. Susu Chen, and Dr. Karel Svoboda, came together to understand how cues in our environment can trigger planned movement. Neurons in the human brain are active with diverse patterns and timing. The Motor cortex is responsible for the control of movement. The patterns of the motor cortex differ in the phases of movement. The transitions between these phases is a critical part of movement. The brain areas controlling these transitions were a mystery.

To identify the parts of the brain controlling these transitions the group of scientists performed their research on mice.They recorded the activity of neurons in a mouse’s brain when doing a triggered movement task. Researchers found brain activity taking place directly after the go cue and between the stages of movement. This brain activity came from a circuit of neurons in the midbrain, thalamus, and cortex. To determine whether this circuit was a conductor or not the scientists used optogenetics. Through the use of optogenetics Dr. Inagaki and his colleagues were able to identify a neural circuit critical for triggering movement in response to environmental cues. Dr Inagaki says that “We have found a circuit that can change the activity of the motor cortex from motor planning to execution at the appropriate time. This gives us insight into how the brain orchestrates neuronal activity to produce complex behavior.

Figure-1

Not only is this important for the use of knowing more about the brain but it also helps to advance studies of motor disorders, such as Parkinson’s disease. By adding environmental cues to trigger movements it could drastically change the mobility of patients.

In Ap Biology class we learned about cell communication. Neurons communicate with each other by releasing specific molecules in the gap between them, called the synapses. The sending neuron passes on messages through neurotransmitters that are picked up by the receptors of the receiving neuron.

How to Keep Your New Year’s Resolutions: The Making and Breaking of Habits

What is a habit? A habit is “a behavior pattern acquired by frequent repetition or physiologic exposure that shows itself in regularity or increased facility of performance“ (Merriam-Webster). With this being the second month of 2022, New Year’s Resolutions are still in many people’s minds. February is statistically the time when individuals give up on their life-changing aspirations that the new-year inspired, “virtually every study tells us that around 80% of New Year’s resolutions will get abandoned around this month” (This Is The Month When New Year’s Resolutions Fail—Here’s How To Save Them). The “new year, new me” mindset is beginning to seem a little too hard to accomplish. If we can create habits that contribute to our new year’s resolutions, maybe they won’t seem so difficult. So, how can we make these resolutions into good habits and break existing bad ones?

New Years Resolutions

Habits are created through associative learning. Essentially, as you repeat a certain behavior in the same context, it becomes an automatic response rather than a thought-out action and that is when it is a habit. When this switch happens, that behavior/action moves from the intentional mind to the habitual mind. So, if we can intentionally make certain changes as a part of a resolution, we will eventually do them without thinking and maybe accomplish a resolution! 

Brain

Now, let’s look at some interesting science involved in the study of habits! Specifically, the dorsolateral striatum. This is a part of the brain that “experiences a short burst of activity” as the brain begins to create a new habit (Revving habits up and down, new insight into how the brain forms habits). As a habit becomes stronger and harder to break, this burst also intensifies. This was proved in an MIT study where rats were taught how to run in a maze and received a sugar pellet reward at the end. As we have learned in biology, neurons are nerve cells that send and receive signals. In fact, we know all about how these signals are transmitted! In this study, using optogenetics, scientists controlled the neurons in the dorsolateral striatum with light. “A flashing blue light excites the brain cells while a flashing yellow light inhibits the cells and shuts them down” (Science Daily). As the rats were running through the maze, if the neurons were excited, they ran faster and habitually, whereas when the flashing yellow light inhibited the cells, the rats slowed down and no longer knew where to go, making wrong turn after wrong turn. Senior author of the study Kyle S. Smith said, “Our findings illustrate how habits can be controlled in a tiny time window when they are first set in motion. The strength of the brain activity in this window determines whether the full behavior becomes a habit or not”. This shows us, it is fairly easy to form habits if you continue it repeatedly as the action first begins! While this can be good or bad, with the other information you will learn in this blog post, I hope that this is encouraging! 

In a recent study rewards were also shown to help form habits. This study explored how giving individuals in India a reward for washing their hands before dinner created good hand washing habits. “The study involved 2,943 households in 105 villages in the state of West Bengal between August 2015 and March 2017. All participants had access to soap and water. Nearly 80 percent said they knew soap killed germs, but initially only 14 percent reported using soap before eating” (Small bribes may help people build healthy handwashing habits). These households were divided into groups. Those that received a reward for washing their hands before dinner did 62% of the time, whereas those who did not receive a reward only washed their hands 36% of the time. This is a big difference! “Significantly, good habits lingered even after researchers stopped giving out rewards” (Small bribes may help people build healthy handwashing habits). Rewards helped create the habit, but once the habit was formed, it was automatic and even without the reward, the habit still took place! Now you may be wondering, why is this information relevant? Well, reward yourself! If your goal is to do one pull-up everyday, give yourself a piece of chocolate every time you do it and eventually you will not need any chocolate! 

So, based on this information, how can we break bad habits? First off, go to a new environment. Due to the fact that habits form from repeated behaviors in the same context, by changing our surroundings, it is much easier to not participate in that behavior. Secondly, repeat a new, replacement behavior over and over. For example, if your goal is to eat less pears, make it a habit to reach for an apple every time you walk into the kitchen. As we know, repetition forms habits! Lastly, keep this new environment and action consistent – don’t start reaching for a banana every time you get home if you have been reaching for an apple when you walk into the kitchen. In order to form a habit it is critical to repeat a certain behavior in the same context. 

Now, we can now create good habits and break the old bad ones! With this information, make this the year that you actually follow through on your new year’s resolutions! Don’t let this month stop you. You have the knowledge and resources, get to it! New year, new you! Good luck! If you have any questions, feel free to comment below!

New Years Resolution

Cocaine’s Abuse on the Body: How Far Does it Go?

Cocaine powder on black table | 🇩🇪Professional Photographe… | FlickrCocaine pictured above

When it comes to cocaine, there is a long list of the drastic. negative effects it has on the human body–not only physically, but mentally as well. When we see major celebrities such as Mac Miller, Don Rogers, and Whitney Houston pass from a cocaine overdose, what do you think plays a part in it?

What is cocaine?

Cocaine is a powerful and highly addictive stimulant drug, which first arose in the US in the late 1800s. It can be snorted, injected, rubbed in one’s mouth, and smoked. It is made from the coca plant of South America. It raises our dopamine levels which cause us to feel joy and relief, however, it damages the natural communication cycle in our brain, leading people to take highter and more frequent doses in an attempt to achieve the same high as when they first began using.

Effect of cocaine on our bodies

Short-term health effects of cocaine include, but are not limited to:

  • extreme happiness and energy
  • mental alertness
  • hypersensitivity to sight, sound, and touch irritability
  • paranoia—extreme and unreasonable distrust of others

Some long-term effects of cocaine abuse include, but are not limited to:

  • headaches
  • extreme weight loss
  • cardiac complications such as irregular heartbeat, cardiomyopathy, and acute myocardial infarction (heart attack)
  • loss of smell/olfactory function
  • mood swings
  • movement disorders, including Parkinson’s disease
  • paranoia
  • auditory hallucinations
  • irregular heartbeat
  • death by overdose
On a cellular level…

Once in our system, cocaine rapidly crosses the blood-brain barrier and binds to various plasma membrane transporters on neurons. Neurons are the main focus here, as our brains are comprised of 3 to 6 layers. What are they? They are “the fundamental units of the brain and nervous system, the cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in-between” (Queensland Brain Institute). Neurons contain cytoplasm, mitochondria and other organelles. Neurons carry out basic cellular processes such as protein synthesis and energy production. Regarding basic cell types and structure, neurons have a cell body comprised of a nucleus and cytoplasm, and also have a mitochondria. The nucleus produces ribosomes which are involved in protein production. The cytoplasm acts as a suspension medium for organelles, and the mitochondria is involved in complex processes of neurotransmission. Overall, this cell body is essential to the neuron’s function as it carries genetic information, maintains the neuron’s structure, and provides energy to drive important cellular activities.

File:Blausen 0657 MultipolarNeuron.png - Wikimedia CommonsNeuron structure pictured

Or, to put it very simply, cocaine alters our brains and DNA in a complex manner, relating to several neurotransmitter systems, leading to seizures and neurological disorders such as Parkinson’s disease, as well as the more mild symptoms listed above.

Crack and cocaine users: are they bad?

Yes, crack and cocaine use is objectively terrible. They can alter our behavior, emotions, physical abilities, and our future children in drastic ways. However, it is important not to villainize those suffering from substance abuse. Rather, we should focus on what causes these people to turn to drugs. Systemic racism plays a large role in who uses and is distributed crack/cocaine. Lack of access to mental healthcare is yet another factor. As a society, we need to do better and be aware of all these things. If you or someone you know may be susceptible or vulnerable to drug abuse, please contact the Substance Abuse National Helpline at 1-800-662-4357.

 

 

 

How Did Our Baby Learn That Word?!?!

Jason Sudeikis’ character is hosting a nice dinner party with his wife played by Jennifer Aniston, and all seems to be going great. Then, all of a sudden, their 12- month-old baby blurts out a curse word! “How could our baby learn such a thing?” In a flashback 8 months earlier, we see the less-experienced parenting pair blurt out some pretty R-rated things in a fit of frustration on the road with their baby in the backseat. And so the punch line sinks in.

In modern day parenting comedies, scenes like this fabricated one are a dime a dozen. But these humorous takes on life always get at least one thing right: babies are sponges. Let’s take a look at why on a cellular level.

image source: https://commons.wikimedia.org/wiki/File%3AComplete_neuron_cell_diagram_en.svg

Prior to birth, most neurons migrate to the frontal lobe of the brain where, during postnatal development, they link together and forge connections, allowing a baby to learn proper responses to stimuli. The “circuits” formed by the neural connections are incredibly flexible during the early months of development (roughly the first 6 months) and can quickly be formed or severed, resulting in a remarkable neonatal human ability to rapidly pick up new knowledge about our surroundings. But how are they so malleable?!

Researchers at the University of California, San Francisco may have the answer! In a study coauthored by neuropathologist Eric Huang, they found neurons forming a chain moving towards the frontal lobe from the sub ventricular zone, a layer inside the brain where nerve cells are formed, in infants up to 7 months old!

This research seems to point to the idea that these new brain cells form connections with the pre-existing neurons in the frontal lobe later in the infant’s development, resulting in more cognitive flexibility for a longer period of time.

To quote the original article by Laurel Hamers, what the new neurons are doing is analogous to “replenishing the frontal lobe’s supply of building blocks midway through construction”.

Huang’s team observed postmortem infant brain tissue under an electron microscope and discovered a group of neurons synthesizing migration proteins, but the real major discovery came with the observation of rare tissue acquired moments after death. The team injected viruses tagged with glowing proteins into the neurons (thus making the nerve cells glow) in the sample and tracked their movement. While infants up to 7 months old were observed with migrating neurons, the researchers recorded the number of migrating cells at its highest at 1.5 months old and saw it diminish thereafter. The migrating neurons usually become inhibitory interneurons which, to quote the original article, are “like stoplights for other neurons, keeping signaling in check”.

So there you have it! To make sure your baby doesn’t learn that bad word, just suck up all the migrating neurons from its brain!

All jokes aside, this research presents an amazing window into the brain development of the most intelligent species on earth! It’s fascinating how it breaks down psychological mysteries using cellular evidence. And it raises new questions about these mobile neurons: When are they created and how long does it take them to move to the frontal lobe?

How do you think this new research will influence our understanding of the creation of social biases? Do you think this will lead to breakthroughs in research on the foundation of Autism spectrum disorders?  Do you have any funny baby stories? Let me know in the comments.

Editing the Brain Using Epigenetic Tools

Epigenetics is a huge part of our life and influences us in ways we may not be aware of. Did you know that it is impossible to create and save new memories without epigenetic tags? The brain is heavily reliant on Epigenetics to do its functions, and this makes it a huge topic of research to figure out the ways in which the epigenetics of the brain could affect certain diseases or memory. Recently special epigenetic molecular tools have been created that can erase specific epigenetic markers throughout the genome. The possible effects these tools could have on the curing of diseases of the brain or psychological ailments are tremendous.

These “epigenetic editing” procedure use either CRISPR (clustered, regularly interspaced, short, palindromic repeats) or TALE (Transcription activator-like effector) systems of modification. These systems can carry an Epigenome modifying enzyme and deliver it a specific site they are programmed to go to. This allows researchers to target very specific epigenetic changes and either shut them down or turn them on and possibly determine their correlation with certain ailments of the brain. “We’re going from simply being able to observe changes to being able to manipulate and recapitulate those changes in a controlled way,” Day said. This quote from Day, one of the researchers of this project, shows that we advance from only being able to observe epigenetic influences on the brain, to being able to manipulate and control them to potential aid us in combating diseases.

Researchers can catalog all of the epigenetic changes involved in forming and preserving a new memory. If we are able to track these epigenetic changes, then could we implant memories in to a person’s mind, by copying similar epigenetic changes? These researchers where also able to trigger not only the place where epigenetic change happens, but also the exact time using optogenetics. This form of using light to control neurons allows researchers to use the TALE system and a light switch apply epigenetic change to very specific brain regions or cell types.

One of the final goals of this research is to eventually be able to use epigenetic as a form of therapy to benefit PTSD, depression, schizophrenia, and cognitive function using the ability to alter epigenetic marks. This can also be used in a similar way to silence mutated genes that are damaging the cells or the body as whole. This form of using TALE and CRISPR to alter epigenetic tags creates a lot of hope for PTSD, depression, schizophrenia, Alzheimer’s, Parkinson’s, Huntington’s and other similar disease treatment options.

Sensing neuronal activity with light

neurons

Researches have recently developed a tool that may help in mapping the neural networks of living organisms using light. Observing these electrical signals of neurons can lead to numerous advancements in our understanding of neural circuitry.

In a collaborative study between Viviana Gradinaru, Frances Arnold and Barbara Dickinson, they developed a method to sense neuronal activity with light. These researchers used a protein named Archaerhodopsin (Arch) and exploited its light responsive qualities. They were able to optimize Arch through a process known as directed evolution. Using this method they created a variant of the Arch protein, called archer1 that acted as a voltage sensor under a red light and an inhibitor under a green light, while generating a light intensive enough to detect. When this protein acts as a voltage sensor it can show which neurons are active and synaptically connected and which aren’t under certain stimuli.

These researchers were able to test Archer1 in the worm C. elegans, which was chosen for its near transparent tissue that made it ideal for observing the luminescent protein. This was the first place they were able to observe the circuits of the neurons light up if they were expressed and dim down if they were repressed. For future studies they hope to make Archer1 bright enough to be detected through opaque tissue and accurate enough to detect voltage changed in more complex, behaving mammals. This study can prove to help us in our understanding of neural networks.

Original papers:

http://www.pnas.org/content/111/36/13034

http://www.nature.com/ncomms/2014/140915/ncomms5894/full/ncomms5894.html  (You can only read abstracts; you have to pay to read the full text)

The “Sleep Switch” Has Been Discovered

Screen Shot 2014-02-25 at 12.07.37 AM

http://www.flickr.com/photos/fourtwenty/2922398332/in/photostream/

If you’re like me, and most of you are since you’re all human, you’ve probably had a night or two where you just couldn’t fall asleep and figured that you had too much going on in your brain.  Maybe, if you’ve taken a biology course at some point or another, you’ve thought that your brain just has too much activity going on and you wished it would all just come to a nice rest.  In reality, if you’re experiencing that little bit of restlessness, your brain isn’t doing enough!  Scientists at Oxford University’s Centre for Neural Circuits and Behavior recently carried out a study on fruit flies in which they determined the “sleep switch” is really just a regulation of certain neurons in the brain which become more active when the body needs sleep.  Although the study was done on an entirely different species, these scientists still believe that the mechanism is comparable in humans due to the presence of similar neurons in the human brain.  The study showed that when sleep is needed by the body, the “electrical excitability” of the neurons increases, leading to the conclusion that their activity is related to how sleep is triggered.

While this recent discovery has already been inspiring new ideas on how to combat sleep disorders, it is really a step towards the much more basic question, “Why do we (animals) need to sleep?”  The next step towards answering this questions, explains Dr. Diogo Pimentel of Oxford University, is to identify “what happens in the brain during waking that requires sleep to reset.”

This “sleep switch” mechanism is one of two that are theorized to be used in the process of sleep.  The other being the body’s internal clock, which adjusts an animal to certain cycles based on the 24 hour day.  At the point of sleepiness, “The body clock says it’s the right time, and the sleep switch has built up pressure during a long waking day,” explains Professor Miesenböck, in whose laboratory the study was conducted.

Original Article: http://www.biologynews.net/archives/2014/02/19/scientists_identify_the_switch_that_says_its_time_to_sleep.html

Can Scientists Create a Brain?

 

attributed to hawkexpress

attributed to hawkexpress

The brain is one of the few things that scientists struggle to understand. For now, the only brain models you could find is one made of plastic or rubber. In a recent study, Viennese scientists Madeline Lancaster and Jürgen Knoblich have created “cerebral organoids”. These “cerebral organoids” are neural balls, about the size of a BB pellet. It is the most complex brain structure that has been created in a lab.

The scientists that created this placed cells in a nutrient broth for two months. After this time, the cells specialized into neurons that can be found in distinct parts of a developing brain such as  hippocampus, retina and choroid plexus, which produces cerebrospinal fluid in the brain. Although they look like clumps of tissue, the “cerebral organoids” had “discrete parts of the cerebral cortex, the outer sheet of the human brain that’s responsible for advanced thought processes.” The organoids also sent electrical messages and some groups of young neutrons moved from one place to another, an activity necessary to populate a brain with neurons. Also found abundantly in this tissue was a stem cell called radial glial stem cells, which is important to keep the number of neurons growing.

In order to create the organoids, the scientist must take human stem cells either from an embryo or from adult skin samples altered to an embryo-like state. The cells grow for a few days in a dish and medium and then moved to a nutrient broth to grow neuroectoderm tissue, the tissue that makes the beginnings of a brain. Then, the researchers inject the cells into a gel that gives a strict,”scaffold” to grow on. The final and most important step was to place the gel droplets into spinning flasks with nutrients. This was important because the “spinning motion distributed oxygen and nutrients to all of the cells in the organoid”  After two months, the cells stopped growing. Although they are still alive, they stop dividing and reach maximum size.

This research gives a very important window into the study of the brain, especially the study of brain development.  Although this information is groundbreaking, the organoids lack many important systems that the brain has.

Helpful links

http://www.ninds.nih.gov/disorders/brain_basics/ninds_neuron.htm

http://www.ncbi.nlm.nih.gov/pubmed/23995685

http://www.sciencenews.org/view/generic/id/352830/description/Tiny_human_almost-brains_made_in_lab

 

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