A single gene is the key to nicotine addiction, and researchers say this discovery is expected to help millions of smokers quit bad habits that are harmful to their health. At present, more than 4 million people worldwide die from smoking-related causes every year. The harm of nicotine in smoke to human body goes far beyond the lungs. A research report recently released by the Asia-Pacific Group Cooperative Research Organization (APCSC) shows that smoking is an important cause of fatal cardiovascular diseases in China. In 20 years, China will face the death peak caused by smoking. Researchers in California, USA, not only identified gene molecules closely related to smoking addiction, but also cultivated a transgenic mouse to facilitate the study of whether other genes are related to smoking addiction. The research team began to cultivate mice with this single gene that is particularly sensitive to nicotine. These transgenic mice were raised in the environment with the least nicotine content-the concentration is only equivalent to 1/50 of the nicotine concentration in the blood of an ordinary smoker. Once addicted, it will show a sense of dependence on nicotine, just like smokers like cigarettes. The report was published in this Friday's issue of Science.
According to the report, the manifestations of dependence behavior include addiction reaction, increased tolerance and sensitivity, especially at low doses of nicotine.
For humans, when a small amount of exciting dopamine is absorbed, the addiction reaction comes. Dopamine is a chemical released by nicotine, which can calm the brain. The body's tolerance to drugs has increased, leading to more and more smoking. Henry Lester, a professor of biology at California Institute of Technology and one of the 65,438+00 authors of the report, said that increased sensitivity means that if you don't take nicotine, you will feel uncomfortable.
For mice, the researchers saw the addiction reaction that mice chose more nicotine samples than salt samples, and the change of their body temperature was the performance of their tolerance changes, while the mice running around showed that their sensitivity to nicotine deficiency was increasing. Other researchers agreed with the study. The same group of researchers said that this discovery not only provides direct evidence for how to rely on nicotine, but also solves the fundamental problem about smoking addiction genes. If this discovery in mice is also effective for people, it will point out a new goal for developing new drugs to quit smoking. When nerve cell receptors are specially used to receive the chemical acetylcholine, nicotine will be anchored in nerve cells, and we will rely on nicotine. Once nicotine fills it, dopamine will be released. But it is not easy to find out the exact location of nicotine parking, and more research is needed.
According to the latest report from Reuters, American researchers released new research results on Thursday, showing that genetically modified mice are extremely sensitive to nicotine. This phenomenon will help scientists to clarify the specific reasons of human addiction and solve the mystery of smoking addiction. In the journal Science published this Friday, the researchers added that studying this behavior of mutant mice will help medical scientists develop new smoking cessation drugs. Andrew Tepa of the University of Colorado and Henry Lester of the California Institute of Technology are leading a research team to carry out related experiments. They stressed: "Nicotine addiction is one of the main causes of preventable death in the world. Every year, about 940 million deaths on earth are related to smoking. " Scientists believe that a substance called nicotinic acetylcholine receptor is directly related to smoking addiction. Lester and his colleagues successfully cultivated a mutant mouse by using the "α4" part of this receptor, and were surprised to find that these mice were extremely sensitive to nicotine.
The communication between brain cells is mainly carried out through the transmission of a chemical component of a neurotransmitter or information carrier in the gap between neurons called synapses. Acetylcholine is one of these neurotransmitters, which can activate some brain cells to release another neurotransmitter-dopamine. Dopamine is closely related to human pleasure. Once the activation of other cells is completed, acetylcholine is immediately decomposed by a biochemical enzyme called acetylcholinesterase. Nicotine is similar to acetylcholine activating cells to release dopamine, but it will not be decomposed by acetylcholinesterase.
Lester pointed out in a report: "It is precisely because of this characteristic that nicotine can last for several minutes instead of milliseconds in synapses. Its existence excites neurons for a long time and releases a lot of dopamine, which causes human pleasure. Most scientists believe that this phenomenon is the main reason why nicotine is addictive. " "If scientists can find a way to prevent nicotine from entering brain cells, it will be possible to treat smoking addiction. However, this is a very complicated technology. Before we fully understand how to treat addiction, we must divide the research into several independent steps to verify it. But I personally think that nicotine addiction will be the first addiction problem solved by human beings, because we already have so many materials and means to study it. " American researchers said today that genetically modified mice are particularly sensitive to nicotine, which may help scientists thoroughly understand why people are addicted to cigarettes.
Reuters reports that scientists have found that nicotinic acetylcholine receptors are directly related to smoking addiction. Brain cells use a neurotransmitter, a chemical that carries information, to communicate. This substance can jump the nerve bonds between nerve cells. Acetylcholine is a neurotransmitter that can activate some cells to release dopamine, which is related to a happy mood. Once the task is completed, acetylcholine is rapidly broken down by an enzyme called acetylcholinesterase. But nicotinic acetylcholine is not decomposed by acetylcholinesterase. Henry Lester of California Institute of Technology, who participated in the research, said in a statement: "So it will stay in the synapse for a few minutes instead of milliseconds, and activate the neurons behind it to get excited quickly for a long time, and then release a lot of dopamine." "Most scientists think this is the key to nicotine addiction." If we can find a way to prevent nicotine from entering brain cells, smoking addiction may be cured. Lester said: "This is a very complicated way, and we must go step by step to fully understand it, but I personally think that we will overcome the problem of smoking addiction first, because we have many ways to study it."
Neurotransmitter research
Introverts and extroverts not only have different blood flow pathways, but also each pathway needs different neurotransmitters. As we said before, Director Hammer found that high novelty seekers, based on their genetic makeup, need to seek stimulation and stimulation to meet their more demand for dopamine. I think they are like typical extroverts. In addition, studies have shown that the nerve conduction pathway used by extroverts is stimulated by dopamine. Dopamine is a powerful neurotransmitter, which has the greatest relationship with exercise, attention, alertness and learning. Rita Carter thinks in Mapping the Mind: "Too much dopamine seems to lead to hallucinations and delusions. Too little dopamine can lead to panic and inability to start voluntary actions (that is, actions controlled by the will), which is related to meaningless feeling, drowsiness and pain. Low dopamine can also lead to attention deficit and withdrawal. " It is very important for your body to have the right amount of dopamine. Besides, it has other important functions. Steven Hyman pointed out in his book States of Mind: "One of the most striking features of dopamine is that it is a reward system. That is to say, from the result,' that's good, let me do it again, let me recall how we did it.' "That's why cocaine and amphetamines are so addictive-they increase dopamine.
Because extroverts are not sensitive to dopamine, but they need a lot of dopamine, how can they get enough dopamine? Some parts of the brain release some dopamine. But extroverts need dopamine partners. Adrenaline is released by the activities of the sympathetic nervous system, so there is more dopamine in the brain. Therefore, the more active and extroverted people are, the more happiness will be stimulated and dopamine will increase. Extroverts feel great when they have somewhere to go and friends to play with.
On the other hand, introverts are highly sensitive to dopamine. Too much dopamine will make them feel too excited. Introverts use a completely different neurotransmitter acetylcholine in their dominant nerve conduction pathway. In their book Wet Mind, Stephen Kosslyn and Oliver Koenig studied the nerve conduction pathway of acetylcholine in the brain. Guess what? This is the same as the nerve conduction pathway of introverted people envisaged by Dr. Johnson. Acetylcholine is another important neurotransmitter, which is related to many important functions in the brain and body. It affects our attention and study (especially the study of perceptual knowledge), affects us to keep a calm and lively mood, and uses long-term memory to initiate intentional actions. When we are thinking and experiencing, it stimulates us to produce a beautiful emotion. At present, many studies on acetylcholine have strengthened our understanding of the brain and body of introverts.
Acetylcholine is the first neurotransmitter we discovered, but when other neurotransmitters were discovered, the focus of research turned to new discoveries. However, it has recently been found that Alzheimer's disease (Alzheimer's Harmo's disease) is related to acetylcholine deficiency. The results of this study urge people to do more research on acetylcholine and the relationship between acetylcholine and the process of memory and dreams. Acetylcholine seems to play an important role in our sleep and dreaming state. When we are in the rapid eye movement sleep stage (that is, the rapid eye movement stage), we dream. Acetylcholine is released during rapid eye movement sleep, which makes us dream, and then makes us paralyzed (no random movements), so that we don't "gesture" what we are dreaming when dreaming. Researchers have found that during REM sleep, we need sleep to organize our memory and change it from short-term memory to long-term memory. As Ronald Kotulak said in the book Inside the Brain, "Acetylcholine is the lubricating oil that makes our memory machine perform well. When it is dry, the machine will become inflexible. " Another interesting news is that estrogen can prevent the decrease of acetylcholine. This is also one of the reasons why women will feel memory decline with the decline of estrogen during menopause. Therefore, introverts need a limited range of neither too much nor too little dopamine, and acetylcholine is at a good level, so as to feel calm and free from depression and anxiety. This is a comfortable area, but it is too small.
What neurotransmitters are used by introverts and extroverts is a key issue, because when neurotransmitters are released in the brain, they also enter the autonomic nervous system. This system connects our brains with our bodies and has a great influence on how we act and react. Which neurotransmitters move in which nerve conduction pathways and how they relate to different autonomic nerve centers, I think the relationship between them is an important factor to solve the mystery of personality. Extroverts are related to dopamine/adrenaline, energy consumption and sympathetic nervous system, while introverts are related to acetylcholine, energy reserve and parasympathetic nervous system.
nicotine
Why do introverts and extroverts feel different in thinking and doing things? The clue to explain this confusion comes from an unexpected source-why people are addicted to smoking. In the study, smokers reported that they smoked because they thought smoking could better concentrate, study and recall more easily, and they felt "refreshed". Receptors for nicotine and acetylcholine in the brain? The use is very similar. Acetylcholine can increase attention, memory and happiness, and the nerve conduction pathway of acetylcholine dominates introverts.
Nicotine can also cause the body to release dopamine, affect the decomposition of serotonin and norepinephrine, and also affect all active neurotransmitters in the body when extroverts are active. Cigarettes can make people at both ends of the introversion/extroversion continuum feel happy, so it is no wonder that so many people smoke despite knowing the harm of smoking.
Introduction:
Mental health is inseparable from external factors. In addition to your inherent brain physiology, substances, activities and belief systems will affect your brain in different ways. This section will explain these factors. These are over-the-counter treatments, not natural (herbal) treatments. Once these factors are integrated with individuals, they are different from concrete substances, and will be frequently used in daily life, which will easily be "abused" and affect mental health. In this section, we will look at the effects of caffeine, nicotine, alcohol and drugs on behavior and mental function. Exercise and religious belief are two very common activities in American society, which also have an important impact on mental health care.
Nicotine addiction
Nicotine is one of the most abused drugs in the world, which is also attributed to its addiction to some extent. The function of nicotine is related to the dopamine system, which has the characteristics of reward and addiction. When combined with the ventral tegmental area, nicotine can reduce the release of dopamine in this area and nucleus accumbens. The ventral tegmental area and ventral septal nucleus are responsible for reward, pleasure and addiction, and serotonin and norepinephrine also play a role in nicotine addiction. Serotonin receptor antagonists antagonize the conditioned place preference of nicotine, while serotonin receptor agonists can trigger the release of dopamine (Singer, 2004). Norepinephrine is also involved in the reward process. When norepinephrine is completely deficient, it can desensitize mice to psychostimulants and opioids (Singer, 2004).
Besides the biochemical mechanism that nicotine has been proved to be addictive, there may be other reasons for continuing to use the substance, which may also have an impact on cognition. Nicotine can increase the concentration of acetylcholine in sebum and hippocampus, and dopamine in hippocampus and frontal cortex (Singer, 2004). Hippocampus and memory are related to learning, while frontal cortex is mainly related to higher brain functions, such as memory, thinking and reasoning. In this way, the cognition of nicotine abusers will be affected (Singer, 2004).
The role of serotonin in the battlefield is as significant as its ability to increase dopamine content in nucleus accumbens. Serotonin can also affect cognition, which has been verified in animal experiments. When serotonin decreases, rats will fail in maze and avoidance experiments (Singer, 2004). Norepinephrine also affects reward and cognition. When the concentration of norepinephrine in the frontal cortex decreased, the dopamine level in the nucleus accumbens increased. The increase of dopamine level is mainly regulated by inhibiting GABA neurons, glutamate projection and excitatory prefrontal cortex projection (Singer, 2004). All these processes are related to cortical function, so norepinephrine is related to reward and cognition.
conclusion
By reading this chapter, we can know that there is an obvious correlation between these diseases and the mechanism of action. Body and mind are extremely complex, and changes in one field usually affect other fields.
Other diseases, drugs and auxiliary drugs not covered in this chapter. However, the above is the most common and commonly used among the American population. As the content of the article was published in New Science, relevant research is currently under way. The mechanism of action of special drugs and the breakthrough of neurochemical mechanism of diseases have not touched the essence yet, and they are floating on the edge.