Dopamine’s Activity in the Brain
Dopamine is a neurotransmitter called the “motivation molecule”, that that plays a key role in the reward-motivation behavior mechanisms, providing the drive and focus needed to get stuff done. It's also involved with the “pleasure system” of the brain to create a feeling of enjoyment and a sense of reward. Things such as getting food, sex, making money, earning praise, etc. increases dopamine and the feeling of pleasure. Most addictive drugs increase dopamine activity in the brain.
It is also involved heavily in the following:
• Reward and pleasure centers.
• Attention and Learning
• Sleep and Overall Mood
• Behavior and Cognition
It plays an important part in morning wakefulness as it inhibits norepinphrine’s melatonin producing effects and shuts off melatonin production in the morning when the brain needs to awaken.
People that suffer with low dopamine often experience hopelessness, worthlessness and struggle to handle stress. These individuals will often isolate themselves from others and have self-destructive thoughts and behaviors.
Being easily distracted and having trouble focusing and finishing tasks can be signs of early dopamine deficiencies. Long-term, poor dopamine signaling can result in hand tremors, slowness of movement and pre-Parkinson’s symptoms. Other issues involving low dopamine include schizophrenia, autism and attention deficit hyperactivity disorder (ADHD) and drug abuse. [1]
Individuals with low dopamine also display increased levels of impulsiveness. A 2012 study using 23 adults were given a hypothetical choice between receiving a smaller amount of money immediately or a significantly larger amount at a later time. The individuals who made the impulsive choice for immediate money demonstrated less impulsitivity and chose to wait for the larger sum after taking a drug that blocks a dopamine degrading enzyme (so they had more dopamine). [2]
It is possible to have too little or too much dopamine production. This is often due to the level of stress the individual is under.
Phases in stress-response:
- In phase I, alarm response to stress, we produce more dopamine and other catecholamines.
- In phase II adrenal fatigue, stress hormones begin to plummet.
- In phase III, when we have adrenal exhaustion, we produce too little because the cells are burned out. Our dopamine secreting cells can be overwhelmed with stimulus to produce dopamine and begin to shut down, effectively reducing our ability to produce stress hormones on demand.
In addition, when too little precursers such as phenylalanine and tyrosine are available due to low protein diets or more commonly due to low stomach acid, low conversion factors (such as a B6 deficiency) can create an inability to produce enough dopamine. Also, poor sleep, hypothyroidism and hypoglycemia will lead to poor dopamine repletion and symptoms of low dopamine. [3]
Caffeine is the most commonly used psychoactive substance, and consumption by adolescents has risen dramatically in recent years. A study have shown that caffeine consumption during adolescence lowers basal dopamine levels and increases cocaine-induced dopamine release in the nucleus accumbens (NAc). [...] Caffeine intake is positively correlated with substance-use disorders (Kendler et al, 2006) and has been shown to increase illicit drug use and other risky behaviors in young adults (Miller, 2008). Despite the increase in caffeine consumption among adolescents, very few studies have examined the behavioral or neurobiological effects of adolescent caffeine consumption. We provide new enlightening data suggesting that enduring alterations in reward pathway signaling are an important consequence of chronic adolescent caffeine consumption. On the basis of these findings, it is clear that more extensive studies are needed to determine caffeine’s effects on brain development and possibly the permanent effects of adolescent caffeine exposure. [4].
