Modafinil 200 Australia was originally developed to treat narcolepsy, but it is now increasingly used off-label as a cognitive enhancer. It is often taken by people who need to focus for long periods of time, such as students taking exams or workers at deadline-driven jobs.
This study used positron emission tomography with [11C]raclopride and dopamine transporter radioligands to measure the effects of modafinil on dopamine in the brain. Results showed that modafinil decreases DA and increases D2 and D3 receptors in the nucleus accumbens.
Dopamine
Dopamine is a brain chemical that enables neurons to communicate and control movement. Low levels of this chemical cause a variety of symptoms, including tremors, stiffness, and poor balance and coordination. It is also an important hormone in the body and regulates blood sugar. It plays a role in stress responses via the hypothalamic-pituitary-adrenal axis. It may also play a role in psychiatric conditions, such as depression and bipolar disorder.
While modafinil does not affect the dopamine system in monkeys, it has been shown to block dopamine transporters and increase dopamine in humans (including in the nucleus accumbens). These results suggest that modafinil increases dopamine in the human brain and could lead to addiction. In addition, the drug has been found to interact with several other neurotransmitters and hormones, such as epinephrine and dopamin.
Modafinil (Modalert 200 mg) is a stimulant that enhances cognitive performance in normal people. It is the first pharmaceutical nootropic agent to be clinically validated. Although it is not a cure for narcolepsy, it can help patients get the most out of their lives by waking them up and improving their cognition. However, it is difficult to determine how much benefit these drugs provide for people who do not have narcolepsy or other sleep disorders.
GABA
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that reduces the activity of brain cells. It is part of a large group of chemicals called neurotransmitters, which facilitate communication between brain cells. Some neurotransmitters heighten brain activity, while others inhibit it.
The balance between these two types is crucial to a properly functioning brain and body. GABA is produced inside the brain and then transmitted to other brain cells via specific receptors. GABA inhibits the release of another neurotransmitter, glutamate, and vice versa. In this way, a delicate balance is maintained between the inhibition of GABA and the activation of glutamate.
Researchers have found that a small dose of modafinil enhances cognition. This finding is consistent with the idea that modulators of GABA receptors improve cognitive performance in healthy subjects, as well as in those with sleep disorders. The drug has a lower liability to abuse than traditional psychostimulants.
In addition to its waking effect, modafinil has been shown to improve the performance of patients with various conditions, such as attention deficit disorder, age-related memory decline, depression, idiopathic hypersomnia, myotonic dystrophy, and jet-lag treatment. It is also less likely to have side effects, such as excessive locomotor activities or jitteriness, than other stimulants. This is likely due to its inhibition of DAT, which allows dopamine to be transported from the nucleus accumbens into the brain.
Serotonin
Serotonin is a neurotransmitter that plays an important role in many physiological processes. Low levels are associated with depression and other mood disorders. High levels are associated with feelings of well-being. Serotonin acts as a hormone and regulates sleep, appetite, anxiety, digestion and blood clotting. It also plays a role in mood disorders, seasonal affective disorder and the circadian rhythm. Low levels of serotonin are also associated with poor sleep.
A recent study found that modafinil enhances cognition in healthy individuals, independent of its effects in narcolepsy and other sleep disorders. The study included a placebo-controlled, double-blind design and was performed on healthy young volunteers. Participants were administered modafinil or a placebo, and their mood was assessed with a series of scales. They self-reported feeling alert and enthusiastic, anxious or restless, and sleepy, on a scale of 1 (not at all) to 10 (extremely).
Brainstem serotonin neurons send descending projections that modulate incoming nociceptive information in the spinal cord, and ascending projections that terminate in cortical and limbic regions that may modulate the psychological perception of pain. The brainstem serotonin system also controls the release of melatonin, which induces sleep and suppresses rapid eye movement (REM) sleep.
The complex way in which serotonin modulates physiologic and pathophysiologic processes presents both an opportunity and a challenge for the development of new drugs. Serotonin receptor subtype-selective drugs might help in a number of psychiatric disorders by targeting the mechanisms that cause the abnormal serotonergic function.
Norepinephrine
Modafinil increases monoamine levels by inhibiting the reabsorption of dopamine and norepinephrine at the blood-brain barrier. Hence, it increases the availability of these neurotransmitters for transmission to other neurons. It also promotes the activity of the GABA a receptors in the brain, which reduces inhibition and enhances learning and memory. This effect on adenosine is one of the main mechanisms through which modafinil enhances cognitive performance in people with narcolepsy and other sleep disorders.
In some studies using BOLD fMRI, Modafinil has been shown to increase the strength of connectivity between cortical regions. The results are interpreted with graph-based methods that highlight and unravel statistical associations between changes in brain activity.
For example, Della Marca et al (2004) used this method to analyze the effects of modafinil on sensory evoked potentials in the primary visual cortex (BA17). They found that modulation by modafinil of subcortical afferents from VLPO neurons reduced their inhibitory actions on BA17 neurons. The result was an enhanced ability to process visual stimuli, which is associated with increased cognitive performance in narcoleptics.
Norepinephrine is a neurotransmitter released by adrenal glands in response to stress or danger, as well as physiological demands. It travels to the rest of your body, where it causes blood vessels to constrict and increases heart rate in order to increase the flow of oxygenated blood. Dysregulation of norepinephrine signaling is associated with depression, anxiety disorders and ADHD. Modafinil can increase vigilance, reduce lethargy and improve concentration.