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What Is The Reward Center Of The Brain

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Recovering From Addiction With Effective Substance Abuse Treatment

Brain Reward: Understanding How the Brain Responds to Natural Rewards and Drugs of Abuse

Due to the hold reward pathways have over an individuals actions, it can be nearly impossible to break free of an addiction cycle without support in treatment.

Treatment options will vary, depending on the severity of substance abuse. Adequate substance abuse treatment has proven to play a critical role in a persons ability to stop addictive behaviors and restore control over their lives.

The most effective treatment types work to address the individuals unique issues, including what caused them to begin substance abuse. By confronting both the mental and physical aspects of addiction, individuals are more likely to have a successful recovery outcome.

The Brain Reward Depression And Anxiety: When Neurons Get Their Wires Get Crossed

What happens when joyful experiences and naturally pleasurable stimuli dont produce a positive reward mechanism in the brain? Depression and anxiety or a generally lowered sense of well-being.

News stories about the drug crisis in the U.S. have highlighted the brain-reward-addiction connection, a story angle that plays well in the media but somewhat overshadows the brain-reward-mood connection. Just as addiction stems from a disruption in the brain reward circuitry, so do depression and anxiety, but in a different way. Scrambled pathways in the brains reward circuitry can lead to negative responses to positive stimuli, causing overlapping or co-occurring depression and anxiety.

According to research, people who suffer from depression have reward-circuit deficits. For those with depression, which affects roughly 20% of the U.S. population, pleasure-reward communications in the reward system are inhibited, resulting in something called anhedonia, where the person is unable to experience pleasure from activities that are usually enjoyable music, hobbies, exercise, sex and social interaction.

Roughly 70% of the folks we treat for substance use disorders have a co-occurring disorder like depression or anxiety, says Jason Powers, MD, the chief medical officer of The Right Step and Promises Austin. Many experts in the field believe this is due to low dopamine tone or low hedonic tone in some people, where they have a reduced ability to experience pleasure.

Mapping Pleasure In The Brain

The experience of one pleasure often seems very different from another. Eating delicious foods, romantic or sexual pleasures, addictive drugs, listening to music, or seeing a loved one: each feels unique. The only psychological feature in common would seem that all are pleasant. However, the difference in ones subjective experiences is not necessarily a good guide to the underlying neural mechanisms. Those neural mechanisms may overlap to a surprising degree.

Over the last decades, a growing set of results from neuroimaging studies have suggested that many diverse rewards activate a shared or overlapping brain system: a common currency reward network of interacting brain regions. Pleasures of food, sex, addictive drugs, friends and loved ones, music, art, and even sustained states of happiness can produce strikingly similar patterns of brain activity . These shared reward networks include anatomical regions of prefrontal cortex, including portions of orbitofrontal, insula, and anterior cingulate cortices, as well as often subcortical limbic structures such as nucleus accumbens , ventral pallidum , and amygdala . An implication of the common currency hypothesis is that insights into brain hedonic substrates gained by experiments using one kind of pleasure, such as food liking, may apply to many other pleasures too.

Three-dimensional comparison of hedonic sites in rat brain and human brain Hedonic coding in the human orbitofrontal cortex

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When Our Brain Rewards Us

But what about pleasure? Whats the purpose of all the positive things we mentioned above? Believe it or not, the motivation and well-being you find when you behave in a certain way is also part of your development. Youre often surrounded by many different stimuli and situations. You need to prioritize them and concentrate on the things that can work to your own benefit.

For example, your brain will reward you when, after a stressful day at work, you decide to meet up with a special friend to chill out with a drink. Itll also give you a dose of dopamine when, in the middle of a hot morning, you go and get a glass of water to stay hydrated. The purpose of this neural structure, then, is to keep you motivated so you can carry out specific actions that it considers appropriate.

Reward And The Basal Ganglia

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The reward circuit, now considered to be embedded within the cortico-basal ganglia network, is a central component for developing and monitoring motivated behaviors. Historically, however, the basal ganglia were best known for their relevance to motor functions, based both on the neuropathology of movement disorders and the idea that basal ganglia pathways return primarily to motor cortex . Our concept of basal ganglia function has dramatically changed in the last 30 years, from a purely motor or sensory-motor function to a more complex set of functions that mediate the full range of goal-directed behaviors, including emotions, motivation, and cognition. The change resulted from several lines of inquiry, but at the center was the demonstration that frontal cortical information passing through the basal ganglia returns to all of the frontal cortex, not only to motor cortex. This idea first arose in the late 1970s with the development of Heimer’s classic concept of the VS and VP. The discovery added a separate functional loop, the limbic loop, within the basal ganglia . Subsequently, the anatomical demonstration of this circuit provided the evidence for other functional loops . The idea of separate cortical loops in the basal ganglia was expanded in primates to include several parallel and segregated circuits based on the finding that each general functional area of cortex is represented in specific regions in each basal ganglia structure .

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The Edges Innovative Treatment Programme Retrains Addicted Brains

Today, we know that all addiction operates on the brain in essentially the same way. To effectively treat it, we must retrain the brain to seek out healthy, pleasurable experiences rather than those derived through the use of a substance or engagement in an addiction process or behaviour. This is a long and difficult process, but it can be done. We see it regularly at The Edge addiction treatment centre.

Our addiction counsellors work with young men between the ages of 18 and 28 who have had their own brains hijacked by addiction. We combine cognitive behavioural therapy with one-on-one counselling and physical training to help our participants rewire their reward centres. Our ground-breaking treatment process is transforming young lives.

If you would like to learn more about how our treatment specialists can help you, please dont hesitate to contact us today.

Causal Hedonic Hotspots For Hedonic Enhancements

Yet hedonic gains of function can be produced by neural events in several forebrain structures, resulting in intense pleasure reactions. Animal affective neuroscience studies have recently identified a network for generating hedonic enhancement of liking reactions, embedded as a set of small hedonic hotspots distributed among several limbic structures throughout the brain, ranging from cortex to brainstem. Each hotspot can specifically amplify orofacial liking expressions elicited by sweetness in rats, when neurochemically stimulated by an appropriate drug microinjection. Hedonic hotspots have been found in subcortical forebrain nucleus accumbens and connected ventral pallidum, in the brainstem parabrachial nucleus of the pons, and may now be emerging in limbic areas of prefrontal cortex, including orbitofrontal cortex and insula .

The size of hedonic hotspots mapped so far is each about 1 cubic millimeter in volume in rats . By comparison, each structure that contains a hotspot is much larger. For example, the entire nucleus accumbens comprises nearly 10 mm3 in rats, but its opioid hedonic hotspot located in the rostrodorsal quadrant of medial shell constitutes only 10% of total NAc volume . In other words, as far as is known, nearly 90% of the remaining NAc may lack capacity to enhance liking reactions, even for mu opioid stimulation.

Hotspots at top and bottom of the brain?

Interaction between hotpot site and neurochemical stimulation

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What Situations Activate The Reward System

As we already mentioned, the reward system is actually an adaptive function. Thus, its related to the basic needs that allow us to survive individually and as a species.

Firstly, its responsible for aspects such as eating, drinking, or having sex. The taste of food gives us pleasure, the same as drinking water when youre thirsty, or taking part in sexual activity. Thus, it stimulates the learning and repetition of these actions.

However, these arent the only functions that motivate this system. For example, you can experience pleasure with games, sports, and, of course, drugs. Many studies have shown that cocaine, among other substances, also activate this circuit.

Inevitably, this may lead you to think about the risks of the brains reward system. Addictions are the negative part of this wonderful adaptation mechanism.

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The Brain Reward Circuit

Reward pathway in the brain | Processing the Environment | MCAT | Khan Academy

The area of the brain known as the reward circuit or pleasure pathways that is located in the limbic regions including the ventral tegmental and nucleus accumbens has been shown to be activated at varying degrees by both licit and illicit substances. Although different drugs may affect these pathways somewhat differently, they all lead to the release of dopamine, a neurotransmitter that is associated with the experience of reward or pleasure. Importantly, the amount of dopamine released in the brain as a result of substance use is 210 times greater than the release associated with natural stimuli . The amount of dopamine released and the pattern of activation in the reward pathways explains the experience of euphoria or high associated with a particular substance. Thus congruent with the SMH, in the initial stages of addiction, substance use may be viewed by individuals as a way of achieving a reprieve from negative emotional states. After a period of experimentation, individuals may select a substance or family of substances that are the most effective in producing the desired affective state. It is important to consider that individuals’ initial motivation for substance use may or may not reflect a desire for ameliorating negative affective states. It is also possible that individuals’ motivation to use reflects a desire for the high associated with a substance, a need to regulate their overall emotional experiences, or an effort to obtain desired social rewards.

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Addiction And The Dopamine Transporter

Although the details may have been disputed, the central role of dopamine in addiction nevertheless seemed firmly established. And then last May came research that appeared at first glance to contradict the notion that dopamine underlies addiction. The leading hypothesis for how cocaine works in the brain appears to be wrong, said The New York Times. The headline in Nature Neuroscience asked: Hard knocks for the dopamine hypothesis?

Caron points out that pharmacologists have known for a number of years that many psychostimulants are capable of blocking not only the ability of the dopamine transporter to re-uptake dopamine and therefore increase extracellular dopamine concentration, but also the ability of the norepinephrine transporter to re-uptake norepinephrine and the ability of the serotonin transporter to re-uptake serotonin. Previously, the effects on other neurotransmitter systems were not thought to be important because many of the reward mechanisms can be blocked by blocking the dopamine system.

What the study suggests, Caron says, is that addiction does not depend solely on the ability of cocaine to raise the concentration of dopamine. It’s probably much more that cocaine interacts with many other systems, he says, noting the possibility that norepinephrine might also be involved.

Addiction And Dopamine Receptors

Studies of dopamine receptors are helping to shed light on the physiology of craving. There are two major classes of dopamine receptors, according to David Self, of Yale University. He calls them Dl-like and D2-like. Self and his colleagues, who study addiction in rats, report that the two receptor types have certain structural similarities and that their within-cell signaling systems are similar, but they have different anatomical profiles: They tend to be in the same brain regions, but sometimes on different cell types.

Self and his colleagues have found evidence that these two classes of dopamine receptors also function differently in addiction in rats. Craving and relapse seem to involve D2 activation almost exclusively, although both receptors are activated during reinforcement. Self hypothesizes that each receptor is involved in a different motivational phase of the reinforcement process, which he calls appetitive and consumatory . I like to use the terms seeking and having. You can think of D2 receptors as stimulating seeking, whereas Dl receptors stimulate having, he says.

Thus, D2 activation increased drug craving while Dl activation did not, Haney acknowledges. She is not, however, convinced that Self’s hypothesis is correct because she suspects that, at the low doses she used, pergolide acted selectively at the D2 receptor, yet, like ABT-431, it did not affect self-administration.

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The Brains Reward System: How Does It Work

17 January, 2020

The reward system is another curious and complex aspect of our brain. Its a mechanism that allows humans to relate certain situations with pleasure. In reality, its a way to adapt and improve survival.

This is because, when you associate a pleasant sensation with an action, you stimulate learning. For example, the reward system attributes pleasure to sex, which makes people want to do it again. Thus, the survival of the species is assured.

Many brain areas are involved in this circuit. Therefore, studying it is quite complicated and multifactorial. In addition, the brains reward system not only works with basic activities, such as eating or sex.

In fact, its quite important. It even intervenes in drug addiction or rewarding activities, such as playing sports. Due to its importance, we decided to explain the basics of the brains reward system in this article.

The Role Of Ventral Tegmental Area

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One of the most important parts of the entire reward system, the ventral tegmental area is situated in the midbrain, close to the substantia nigra.

The source of many different sorts of neurons, the VTA is most important for its role in the production of dopaminergic neurons. These transmitters are sent from the VTA to different parts of the brain.

Due to the character of the chemicals it produces and sends around the brain, the VTA has an important function in establishing a particular type of behavior.

The reason why this part is usually mentioned with the substantia nigra is the fact that these two elements are two key dopaminergic parts of the brain.

And while the substantia nigra is closely related to the putamen and the caudate the two parts of the striatum the VTA is the source of the mesocortical and mesolimbic pathways. The former ends in the cortical parts, while the latter finished in limbic regions of the brain.

The aforementioned increase of dopamine in the NAc when the brain is stimulated either by affirmative or aversive stimuli has its roots in the VTA.

Namely, the release of dopamine and its projection through the mesolimbic pathway are both triggered by the neurons placed in the VTA.

All this leads to the conclusion that the VTA is an integral part of the entire rewarding system. Because of that, some experts consider this part of the brain an important element in the addiction-developing process.

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The Malfunctioned Mesocortical Pathway

If we suffer from schizophrenia, psychoses, or anxiety, there might be flaws or abnormalities in the functionality of the dopamine stream from the mesocortical pathway to the dorsolateral frontal cortex.

A lower level of dopamine in that pathway can result in feelings of apathy or lethargy, as well as the lack of willpower.

This is so due to the hypoactive stimuli of the prefrontal cortex. Because of that, D1 receptors dont receive enough stimulation, which is also why people with low dopamine levels can suffer from the aforementioned symptoms and other problems in cognitive processes.

In other words, when the prefrontal cortex doesnt receive enough dopamine, many other parts of the brain subordinate to it wont be notified on the potential rewarding experience were about to have. When they dont receive that information, they cant develop the feelings of exhilaration and excitement prior to the forthcoming reward.

As a result, such people can look and feel isolated and depressed, simply because they have low dopamine levels and their brain cannot reach that pre-rewarding state.

Brain’s ‘reward’ Center Also Responds To Bad Experiences

Date:
Georgia Health Sciences University
Summary:
The so-called reward center of the brain may need a new name, say scientists who have shown it responds to good and bad experiences. The finding may help explain the “thrill” of thrill-seeking behavior or maybe just the thrill of surviving it, according to scientists.

The so-called reward center of the brain may need a new name, say scientists who have shown it responds to good and bad experiences. The finding, published in PLoS One, may help explain the “thrill” of thrill-seeking behavior or maybe just the thrill of surviving it, according to scientists at Georgia Health Sciences University and East China Normal University.

Eating chocolate or falling off a building — or just the thought of either — can evoke production of dopamine, a neurotransmitter that can make the heart race and motivate behavior, said Dr. Joe Z. Tsien, Co-Director of GHSU’s Brain & Behavior Discovery Institute.

Scientists looked at dopamine neurons in the ventral tegmental area of the mouse brain, widely studied for its role in reward-related motivation or drug addiction. They found essentially all the cells had some response to good or bad experiences while a fearful event excited about 25 percent of the neurons, spurring more dopamine production.

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