Katılma Tarihi: 15 mart 2005
Yer: United States
|Gönderen: 30 kasim 2019 Saat 00:16 | Kayıtlı IP
Once again, thanks to the National Science Foundation, Medtronic, Pfizer, Park Foundation, and the Dana Foundations for funding an intellectual dvd for the public to be informed on the brain, I have enjoyed watching yet another DVD of the Secret life of the brain this time on adolescence.
In adolescence, the brain is in the process of developing. The prefrontal cortex is a part of the brain that undergoes a major maturation. With a part of the brain that does reasoning, judgement, and self-discipline in the process of still developing, it's not surprising that the teenage years can be a time of turmoil and confusion.
Sometimes the teenage brain fails in ways that challenge even the advanced understanding of its works. Courtney Hook was a normal adolescent with one personality, but he felt symptoms of schizophrenia ( Here is a definition under dictionary.com that I found:
|schiz·o·phre·ni·a ( P ) Pronunciation Key n.
- Any of a group of psychotic disorders usually characterized by withdrawal from reality, illogical patterns of thinking, delusions, and hallucinations, and accompanied in varying degrees by other emotional, behavioral, or intellectual disturbances. Schizophrenia is associated with dopamine imbalances in the brain and defects of the frontal lobe and is caused by genetic, other biological, and psychosocial factors.
- A situation or condition that results from the coexistence of disparate or antagonistic qualities, identities, or activities: the national schizophrenia that results from carrying out an unpopular war)
that he studied in his psychology class by seeing as he described it black holes like tunnels with a small light at the end of them. He would tell his mom that she looked old and that she had black holes going through her eye lids. He said that he felt like he was going crazy. Steven Hyman of the National Institute of Mental Health said that it's hard to imagine a disease that's more cruel than schizophrenia, because it starts out in late adolescents and early twenties, just when an adolescent is finishing up high school and might be planning on going to college and trying to start the adult life.
How does a brain fail to function properly? There's certainty that scientists notice that the prefrontal cortex has to do with the malfunctions. One scientist notified that the prefrontal functions as a conductor of a symphony and makes beautiful music, but if it is not working well, than it sounds like noise.
Courtney says that he had a hard time focusing on one thing. So, researchers did many tests to improve his memory and thought process. Scientists have noticed with the MRI (magnetic resonance imaging showing images of the brain in detail) that schizophrenic brains have ventricles slightly bigger than normal brain ventricles. Ventricles are reservoirs filled with Cerebral Spinal Fluid also known as CSF that is responsible to cushion the brain's delicate tissue. As the ventricles get bigger, parts of the brain will get affected, especially the prefrontal cortex (because the skull is hard, the brain tissue has no where to go when the center of the brain is pushing everything towards the skull).
Researchers have studied and watched home videos of schizophrenic children to see if they have noticeable behaviors. They detected by observing their motor development and there might be correlation to the cause, but since it's still in the experimental process, there is no evidence that this is just one correlation that should be studied only. One psychologist explained that she would notice behaviors such as crawling was different. The schiz baby crawled with one arm doing all the work, another child's hands were not moving simultaneously when running, and lastly another baby was trying to catch a swinging ball with only one hand.
Thus, going back to Courtney, one of the tests done on Courtney was showing slides that affect the emotions (that most people find it as pleasant photos) and viewing his emotional part of the brain by the latest advanced imaging systems. They noticed that most people's brain would appear to change color in the emotional part of the brain, but Courtney's brain lacked some of those areas of color change which tells us that he was not affected by those slides emotionally. The people with schizophrenia, not only are debilitated with emotions(no joy, no sorrow, just empty and black), but also intelectually are damaged. Because they feel they lost everything, themselves, most schizophrenics commit suicide. He wrote once in one of his suicide note "why take death seriously if the quality of life is poor?"
They have presented other youth with schizophrenia, they would see hallucinations, which are frightening visions and voices that do not exist. At University of North Carolina, scientists have found, the part of the brain for thinking processes of sounds that come from the temporal lobes (hearing part), and intrepreted the sounds received. When psychosis is present or when the brain malfunctions, the problems with the chemical dopamine (one of the neurotransmitters that are molecules that send messages from cell to cell across a tiny gap, the synapse) that's normally active in the brain.
In the normal brain, dopamine acts on stimulating receptors on the neuron which is its target, setting off a cascade of electrical and chemical reactions. In the psychotic brain, the levels of dopamine is too much which overstimulates the receptors, messing up with the clear and accurate signals of the brain's ability. Antipsychotic medications relieve psychosis by reducing the impact of dopamine produced (they block the receptors). By reducing dopamine, hallucinations lessen and even may disappear for some. After Courtney took medications, he started to appreciate life and enjoyed life. Every year 300,000 Americans are diagnosed with schizophrenia. We should support foundations funding this sort of research.
There are other problems in the teenage brain as it is in the process of development. Their judgement and reasoning are still not developed in their prefrontal cortex. Twelve and a half million American teenagers suffer from serious drug abuse problems and addiction (these statistics are according to the DVD, it is probably increased today). Jesse Galeter was abusive with alcohol starting at 11 and followed by marijuana than cocaine. Cocaine was so addictive that she had to have it to function ant it wasn't fun anymore, she needed it to survive as she thought. She knew that this wasn't right, and later started therapy.
Scientists have studied the brain's area of desire, apetite and etc. , the area that senses "the high" given by cocaine. As mentioned earlier, the natural chemical or the neurotransmitter of the brain dopamine is produced normally and when there is a substance abuse like cocaine, cocaine goes to the area of the synapse where dopamine is normally sensed and vacuumed back for messages, molecules of the cocaine goes to the little vacuums and blocks the dopamine trying to enter and gives a sensation of desire high which takes them away from the world. Thus it becomes addictive, because they want this desire again.
As the addiction increases, the receptors for dopamine diminish in time, so they die. If there are less receptors for receiving and detecting dopamine, it affects the rest of the body's desires like pleasures, apetite for food, or enjoying life and etc.
Scientists have tested adolescence tolerance of alcohol by placing electrodes on their skull and measuring their brain waves reactions to alcohol. On one young adolescent, Elika, she would feel drunk with a couple of drinks and would have slurred speech when spoken to, but on another adolescent, Justin, he tolerated alcohol well and had not slurred speech and felt no effects of the alcohol as the amount Elika drank. This test was to determine why some teenagers with the same blood level, may become alcoholic and others not. When Elika feels drunk, she would probably stop drinking, but since Justin would not feel drunk, he will probably drink more. Thus, more likely, he will become an alcoholic not knowing the damage that it is doing to his body. Drinking more makes it more addictive. If you have a family history of alcoholism, that is if you are carrying genes of alcoholism and a low response to alcoholism, like Justin, this is a double whammy, your risk is very large to be an alcoholic.
Scientists have examined the brains of cocaine addicts under PET SCAN. They noticed that the adolescents when exposed to films with nature, their brain activity wasn't affected, but when showing a clip of a man about to inhale cocaine, the teenager's brain showed intense brain activity. The area of desire was changing in color to Red, or "hot spots" and growing in size while watching the video. The teenager using cocaine after being shot in the legs living in a bad neighborhood, was paralyzed waist down, and had trembles in his legs thus he was taking a muscle relaxant called Baclophen. He noticed and was surprised, although he had this tragedy in his life of being shot, that his addictions lessened to cocaine as he was taking Baclophen. Scientists noticed after showing the videos with nature and a man sniffing cocaine, the teenager's brain was the same after taking Baclophen, there were no "Hot Spots" present in the brain. This tells us that, Baclophen was a solution for this teenager, but can people with no muscle spasm symptoms take Baclophen to get rid of their addiction for cocaine? Or is there another drug that can do the same affect as baclophen, but not to concentrate on muscle ,but the neurons in the brain? Just like the schizophrenia antipsychotic drugs, but instead of blocking receptors, helping the normal flow of neurotransmitters, this I haven't found in any site of research. If anyone can find more information, let me know please. I'm beginning to have an interest in the psychotic behavior of adolescents, and it's intriguing to learn more about the new findings, especially in the realms of the neuroscience and specifically the neurotransmitters and their function is fascinating. When they are more active and less in our years of development is also very interesting. I would like to know more about dopamine, serotonin, melatonin, Ach and etc. I would also like to know what consists of psychotherapy in adolesence for certain problems?
Being an adolescent is the most demanding time of life, because you learn how to function as a human in a society, you're learning to build friendships, and you're also trying to make plans for life. Since, the prefrontal cortex is still developing and is important in an adolescent's life, to make judgement and reason and the connections to the areas of the brain for pleasure/desire, hearing, memory and etc., it's very important that it is developing right without any interruptions like addictions with cocaine or a disease such as schizophrenia.
This was yet another fascinating DVD, but I think this area lyes my most interest which is neuroscience of the brain, especially in the teenage years, because the brain is still developing in the prefrontal cortex. How does the brain get affected by nature and nurture, genes passed on by alcoholism from family history ,for example, and alcohol which affects the brain's activities and abilities. Another question I have before I bore anyone to death is that just like the schizophrenic patients, when we have nightmares and see visions that may affect us, aren't we considered hallucinators too? Do drugs like pain meds increase hallucination effects?
A personal note: The reason why I ask this, is because last year around this time, I had ankle surgery, and was taking pain meds and I noticed, I would hallucinate frequently at nights and would wake up frightened, because I was so affected by the beings I'd see and they would talk to me. I was taking it seriously, what they said to me in my dreams (or was it a dream?) and later my husband told me, "it's the drugs you are taking," he said "you were never like this before." It does make sense ,because I don't see them as much anymore. Although, sometimes, I do see some beings ever since I was a kid(especially at nights), this occurs normally when I am tired and have been sleep deprived. As soon I say a prayer, they go away.
Could my husband's explanation and my research on neurological development explain what I have been experiencing (a correlation and cause affect) or is it something that I have connections to another dimension that I should try to connect with a dream analyst will not be able to comprehend?
Here is the website for pbs, you can watch clips of the dvd that I saw. Maybe, it might get some of you to check it out from the library nearest you.
Katılma Tarihi: 15 mart 2005
Yer: United States
|Gönderen: 30 kasim 2019 Saat 00:16 | Kayıtlı IP
Further Explanationi of neurological impulse. The "chemical transmission of nervous impulse was conclusively proved".
The experiment consisted of stimulating the vagus nerve of a frog heart in a saline filled container connected to a second container in a way that could allow fluid to flow into the second container which also containing a frog heart. The electrically stimulated heart slowed its pulse and after a brief delay, so did the heart that shared the same fluid but did not receive the electrical stimulus.
Explanation: This is so fascinating to learn this bit of knowledge about a heart of one frog can affect the stimulation of another frog's heart when both are placed in liquid saline. We should note that our neurons that are working constantly right now, for example, when you are reading this writing, the myelinated(which is an insulation fat tissue that speeds up neurological impulses of neurotransmitters===> picture this; It's kind of like the electrical cord for your radio that insulates the wires inside to speed up the process of transmission so we are able to listen to music, if it didn't have insulation, than the electricity that is going through the wire will shock you if you touch it, and the electricity thus spreads out instead of going the direction of the wire, which is not good) neurons in your occipital region (the back of your head) are active ,because your optic neurons are residing in this area. When you see a picture or anything that you are looking at, before you understand or know what it is, your brain needs to translate the image/whatever you are looking at to you. That's another fascinating topic.
OK, what are neurotransmitters again?
Are often called chemical messengers. They affect the polarization of neurons and thus the likelihood they will fire a signal on to more neurons. They may inhibit/decrease this likelihood or excite/increase it.
Most neurons make at least two different kinds of neurotransmitters. Usually one is a Small Neurotransmitter and one is a Large Neurotransmitter. These are described below.
We do not know all of the neurotransmitters that exist and we do not understand (nearly) everything about the ones whose existence we are aware of. When you read or hear about neurotransmitters, you will usually get the impression they do only one thing or play only one significant role in the brain. If you engage your frontal cortex, you will realize this is highly over simplified and misleading. Try to keep in your working memory while studying the brain, how complex it is, how many functions one structure or chemical has and how interdependent they all are.
Most neurotransmitters bind to more than one type of receptor site, with different effects, in different parts of the brain.
There are two different types of receptor sites:
They are called ionotropic and metabotropic. The names reflect the different way they are affected by neurotransmitters. Ionotropic receptors respond by opening or closing an ion channel thus creating an almost immediate action potential and firing response. Metabotropic receptors are more prevalent in the brain and their effects are slower to develop, longer lasting and more varied.
There are many different kinds of metabotropic receptors. All of them have a signal protein that winds its way in and out of the cell membrane 7 times. The receptor site is actually on a part of this signal protein that is outside the neuron. Inside the neuron a protein called the "G protein" is attached to the signal protein. When a neurotransmitter binds to the metabotropic receptor site, a piece of the G protein breaks off. This piece/subunit of G protein may act in one of two known ways. It may move over to bind to a nearby ion channel to open or close it thus inhibiting or exciting action potential. The piece of G protein may instead trigger the creation of a second messenger chemical. These second messenger chemicals diffuse through the cytoplasm and can influence the activity of a neuron in various ways. Auto receptors (The Life of Neurotransmitters) are a type of metabotropic receptor.
So, what is this all saying? In order for us to understand the functions of neurotransmitters, we should know what they communicate with and what changes they make, where do they go after there effect is complete, there are so many questions we should ask ourselves after reading the previous paragraphs. Why should this be so important in knowing this piece of knowledge? This is the core of understanding the Kuran and other religions. First, we should know the details of our thinking. How Allah has created us? Or whomever is your supreme being. We should note that, Yes, God (I say God, because Allah is called God, another name, but a different language, so no misunderstanding on those who dwell on names too much and not the specific intention) knows all, and we shouldn't just accept everything blindly like sheep, we should question everything and thus find the truth that way. All these wonderful scientists have given their lives for years of research, we should notice their findings and appreciate the knowledge gained in time and to be gained in the future.
Let us review: We talked about neurotransmitters within neurons and also talked about receptor sites. What are receptor sites? These receptor sites are so important. It is good to know a little about there function. First of all, they notice by the chemical structure of each neurotransmitter to even accept it at its site. Second, the neurotransmitters fit like a puzzle to the receptor sites. If there was substance abuse such as cocaine, for example, the molecules of cocaine interrupt in the reuptake of some of the neurotransmitters, thus people get this "high" feeling. What does this reuptake mean? Well, there are receptor sites, after the stimulation that the neurotransmitters have caused to occur, affect the next neuron by fitting to the receptor sites like a puzzle, some go back to the neuron that they were previously produced from. Thus, with this reuptake process, the receptor sites or the vacuums in this case, that are located on the neuron that originally produced the neurotransmitters suck them back up so they can be used again. But, with cocaine use or any other substance abuse, the cocaine molecules interrupt this process of reuptake, thus the cocaine molecules block, the receptor sites for reuptake, and the neurotransmitters splatter around, like a coffee spill, and this spill gives this sensation of high or feel good that some might call it. It is so unfortunate that this feel good translates later to pseudoreality.
The Life of Neurotransmitters
Takes place in a neuron as directed by its DNA instructions.
Combining the enzymes the neuron has been instructed to make and building blocks found in the cell (amino acids for example) small neurotransmitters are made in the Golgi complex and large neurotransmitters are made by the ribosomes.
The Golgi complex then packages neurotransmitters in containers called vesicles and they are stored near the membrane that separates the terminal button from the synaptic cleft.
Electric action potential (see The Electric Brain lecture notes) causes the storage vesicle to fuse to the cell membrane and release the neurotransmitters out of the cell and into the synapse.
On the surface of the membrane of the terminal buttons (also called presynaptic buttons) are autoreceptors. Their function is to basically count the neurotransmitter molecules that are released and to determine when it is correct to release more and when release should stop.
Activation of Postsynaptic Receptors
Neurotransmitters bind to their receptor sites on receiving dendrites or cell bodies and give their message.
Deactivation of Neurotransmitters
Neurotransmitters may just diffuse out of the synapse, be taken back into the terminal buttons that released them (reuptake) or be broken down in the synapse by enzymes after which their components or building blocks are reabsorbed by neurons.
How Other Chemicals Affect Us by Affecting Neurotransmitters
Chemicals may be agonists or antagonists.
Agonists facilitate or increase the effect of neurotransmitters by any of the following known methods:
1. Increase the synthesis of a neurotransmitter by increasing the amount of available building blocks.
2. Destroy the enzymes that break apart (degrade) the neurotransmitters when they leak out of their vesicles in the cell or when they are in the synapse.
3. Increase the release of neurotransmitters.
4. Bind to autoreceptors so they can't stop the release of neurotransmitters.
5. Bind to receptors and increase their response to the neurotransmitter.
Ex.: Valium binds to receptors and increases the binding ability of GABA.
6. Block reuptake.
Ex.: Cocaine blocks the reuptake of dopamine and norepinephrine.
Antagonists inhibit or decrease the effects of neurotransmitters by any of the following known methods:
1. Block synthesis by destroying synthesizing enzymes.
2. Cause neurotransmitters to leak out of vesicles so that degrading enzymes destroy them in the cell.
3. Black the release of neurotransmitters from the terminal buttons.
4. Activate autoreceptors so they signal the stop of the release of neurotransmitters.
5. Block the receptors so the neurotransmitter can' t bind to it.
Ex.: Curare (poison) blocks AcH receptors resulting in paralysis and death.
Currently Known Small Neurotransmitters
Short amino acid chains: Includes Glutamate, the most common known excitatory nts and GABA, the most common inhibitory nts.
Monoamine: Made from a single amino acid. Most that we know of are located in the brain stem. These include dopamine, serotonin, epinephrine and norepinephrine.
You will hear and see the terms Catecholamine and Indolamine in reference to important brain activities. Serotonin is classes as an indolamine. Dopamine, Epinephrine and Norepinephrine are classified as Catecholamines.
Soluble Gases: Only recently discovered they are produced in the cytoplasm, exist only for seconds and diffuse out of through the membrane. Nitric oxide and carbon monoxide are two gases that act as nts in the brain.
Acetylcholine: A choline molecule plus an acetyl group.
All small nts are made in the Golgi complex in the neuron. They transmit brief, rapid, direct signals to ionotropic receptors.
Also called neuropeptides(neuro=neuron, peptides meaning they came from ribosomes which exhibit protein sythesis). Large nts are made up of chains of amino acids. There are 50 large nts known at the time of this writing. Endorphins are large neurotransmitters. All large nts we know of are made by ribosomes and then moved through microtubules at the rate of about 40 centimeters (=about 16 inches) per day toward the membrane on the terminal buttons.
Large nts transmit slow, diffuse, long-lasting effects by binding to metabotropic receptors that then make a second chemical messenger that can influence a neuron in several ways. This second messenger can even enter the nucleus, enter the DNA and influence genetic expression!