Appetite Addiction

The hypothalamus is the gratification center of the brain.  It is here that a confluence of nerves meet and converge to regulate hunger.

Synapses, neurotransmitters, minerals, neuropeplides, orexins and receptors fill the brain with data. The hypothalamus then creates a set of instructions based on this information.

The hypothalamic concentration of nerves is responsible for detecting momentary changes in chemistry and energy and for interpreting incoming signals and formulating a response. 

One of the roles of the hypothalamus is to regulate appetite.

 

Nerve transmissions utilize the neurotransmitters: serotonin, dopamine and norepinephrine.  

The monitoring process incorporates hormones, neuropeptides, minerals, amino acids and sugars. This diversity allows the brain to maintain control.

Monitors measure specific markers. These markers bind to receptors, producing a value that the brain evaluates.

 

Any changes in the level of markers are instantaneously detected and adjusted for via a vast network of nerve membrane receptors.

 

Receptors provide the physical sites for the various ions, metabolites, hormones and proteins to bind to.

This binding is information, the 0 and 1s of Nature.

 

All bindings are in a state of either being bound or un-bound. It is the consequences that differ.

 

The hypothalamus is the reward and gratification center. It is responsible for regulating appetite, mood, and pleasure.

 

Drugs, foods, images, smells, moods and thoughts can either stimulate appetite or repress it.  These stimuli produce their effects through the universal phenomena of receptor binding.

Specifically, the stimuli (image, sight, smell, taste, thought or chemical) signals a series of events that culminate in the binding of receptors in the hypothalamus.

In some cases this gives conscious thought and recognition to the event but in most others, they go unnoticed.

 

Knowledge of food depends on all the visual, auditory, olfactory, and gustatory signals received by the hypothalamus. This give understanding to what we eat and why.

 

The neural chemistry of the hypothalamus is thus a prime target for pharmaceutical companies to develop appetite suppressing drugs.

Rather than correct the bad behavior that led to their condition, these companies create drugs that treat the symptoms.

 

Hypothalamus receptors bind to native ligands. When they are properly balanced, hunger occurs only when food is needed.

When they are out of balance, food becomes wanted and overeating occurs.

 

These are the bindings that regulate appetite in health.

 

When they are in dysfunction or when it is overruled by conscious will, overeating takes place.

 

The level of hunger in any given individual is based on the their own, personal set point, no two of which are alike.

Set point is based on fat levels inside specific cells (black adipose)

Set point theory is an explanation for obesity based on the hypothalamus undergoing dysfunction.

 

Fat is monitored and appetite adjusted by a group of specialized proteins that are found in the hypothalamus.

Leptin, orexin, neuropeptide Y and ghrelin are neuropeptides whose levels determine how much eating is needed based on the amount of energy already stored in the body.

Dysfunction in their receptors leads to weight gain.

 

Leptin is a small hormone produced inside adipose (fat). The more fat it contains, the higher the amount of leptin that is released.

The small peptide then circulates to the brain where its presence and level is monitored by nerve cells in the hypothalamus that are involved with energy regulation.

Once bound, leptin represses the urge to eat.  Binding of leptin to receptors indicates that enough energy is stored and producing a natural feeling of not being hungry.

While leptin is produced inside of fat cells, its effect is directly in the brain where it suppresses appetite and the urge to eat.

 

Leptin is a weight loss neuropeptide. In addition to directly repressing hunger, it also blocks the receptor site used by the neuropeptides that stimulate appetitie.

 

Notable is leptin’s ability to bind to the anandamide receptor, which the cannabinoids of marijuana and neuropeptide Y bind to; two compounds known to stimulate hunger and eating. This is the molecular mechanism of the munchies and why many patients, who have little appetite, can benefit from marijuana.

When leptin occupies these sites, it blocks the amadamide sites, therebye repressing the drive to eat.

Leptin level drop following the consumption of fructose rich meals. This may explain the overeating seen in kids since the 1980’s when fructose was introduced as a sweetener.

Leptin analogues are now under investigation as a possible therapy for obesity.

Grelin, another neuropeptide involved with regulating appetitie, is manufactured by the cells lining the stomach.

Ghrelin counters the effect of leptin.  Once ghrelin reaches the brain, it binds to receptors to stimulate appetite. Ghrelin levels are high just before meals, which promotes the desire to eat. Ghrelin levels decrease as the meal is consumed, signalling and end to eating. Due to its promotion of appetite, ghrelin has become a hot target for pharmaceutical intervention.

 

Eating Addiction

Foods are composed of nutrients, fiber, and a library of compounds. Taste, color and odor molecules are wrapped inside a plant’s cells. These physical characteristics are determined by the chemical library found in the whole plant.

These plant compounds or ligands, interact with sensory receptors to initiate an activity. These olfactory, ocular  and gustatory stimuli are then interpreted by the brain to produce the sensations of smell, sight and taste.

 

Eating addictions are not very different from drug addiction. They operate on the same receptor-ligand binding phenomenon that drugs, hormones and neurotransmitters do. Exercise is another type of addiction, a healthy addiction

 

Fast-food restaurants, comfort snacks and prepared food capitalize on food addiction by serving and providing food that is high in fat, a substance that is very addictive to the palate.

The signals are sent from the taste buds in the mouth to be interpreted by the hypothalamus where they are monitored, computed and evaluated via a series of interactions between neuropeptides, hormones and neurotransmitters.

Leptin, orexin, neuropeptide Y, ghrelin, serotonin and dopamine bind to a number of receptors involved in energy regulation, satiety and pleasure. These bindings occur in the Ventral Tegmental area (VTA) of the brain. The VTA responds to fat food and other addictive substances by producing more receptors, thus increasing the potential of addiction.

 

Leptin for example, binds to neurons in the brain involved with energy regulation thereby shutting down the urge to eat. Despite the sufficient production of leptin, obese people continue to eat.

The reason they overeat is similar to why adult onset or Type II (nutritional) diabetics fail to metabolize glucose even though they secrete an adequate amount of insulin.

Obese diabetics produce resisten, another peptide produced by fat cells. Resistin reduces the sensitivity to insulin, causing cells to become resistant to the hormone. In both instances, the receptor no longer recognizes and responds to its proper ligand (leptin and insulin) because its active site has been occupied by an alternative ligand.  In the case of leptin, the alternative ligand is one of a series of neuropeptides.

Orexin, named after the Greek word for appetite, are hunger-stimulating neuropeptides, produced in the hypothalamus. Orexin binds to G-protein coupled receptors setting off a series of events that produce an increase in appetite. Orexin opposes the action of leptin.

 

Over production of orexin induces overeating and sleepiness.

 

Neuropeptide Y is a neurotransmitter in the hypothalamus, involved with energy regulation. Neuropeptide Y increases the urge to eat and the avoidance of physical activity. High levels of this peptide is correlated with increased food intake and decreased expenditure of energy. Stress, high fat, and high sugar levels stimulate the release of neuropeptide Y.

Neuropeptide Y opposes the actions of leptin. Both in the satiety neurons in the hypothalamus and on sites where leptin causes the repression of appetite. This explains the experience of the obese who fail to stop eating despite adequate amounts of leptin.

 

Overproduction of Neuropeptide Y is linked to obesity.

Repression of Neuropeptide Y may lead to weight loss.

 

Both orexin and Neuropeptide Y stimulates appetite and produces an urge to eat. Leptin on the other hand, prevents the synthesis of Neuropeptide Y.

The biological process by which all herbs, drugs and foods produce their effects is through receptor binding.

Receptor binding is the attachment of a ligand to a binding domain on a nerve cell. 

The stimulation may originate elsewhere but all sensations are felt, perceived or otherwise understood, by the neuron exchanges that take place in the brain.

Specific areas control specific functions. One area of interest is the reward and gratification center.

Despite many distinct actions in the brain, all types of addictions converge in producing a common action, activation of the brain's reward circuitry.

The most important part of this circuitry is the mesolimbic dopamine system.

Compounds that result in bindings in this system are addictive. All addictions that lead to dopamine bindings in the Ventral Tegmental area of the brain are based on reward-related motivation.

These dopamine receptors respond to both hedonic stimulants as well as negative ones.

Eating chocolate and living through an earthquake both involve increased amounts of dopamine.

Proper binding is indicative of health. Excessive binding results in addiction.

Improper receptor binding is responsible for most diseases throughout the body. This is especially true when carbohydrates or fats are involved.

Addictions take place in the brain.  It is a chronic process by which steady-state levels of a substance becomes incorporated into normal being.

Addiction requires the need for greater doses to achieve the same result or experience. This is termed tolerance.

Un-satisfaction, due to the absence of the drug, is dependence.  

Tolerance and dependence are the classical signs of drug addiction.

 

 

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