Phosphatidylcholine, common name lecithin, is usually the most abundant phospholipid in humans and plants, often amounting to almost 50% of the total... this is the key building block of membrane bilayers.

In particular, it makes up a very high proportion of the outer leaflet of the plasma membrane. Phosphatidylcholine is also the principal phospholipid circulating in plasma, where it is an integral component of the lipoproteins, especially the HDL.

Acetylcholine (pronounced: ah-see’-til-koh-leen):a nutrient in the brain that plays a key role in memory, learning, and many other brain functions.

Research has indicated that lower levels of acetylcholine are associated with Alzheimer's disease. A neurotransmitter nutrient that allows nerve cells and muscles to communicate. Acetylcholine transmits signals from the nerve endings into the muscle, signaling the muscle to contract, this is believed to help healthy individuals in improving coordination.

Dopamine cannot cross the blood-brain barrier, synthetic dopamine given as a drug does not directly affect the central nervous system. To increase the amount of dopamine in the brains of patients with diseases such as Alzheimer’s, Stroke,and Parkinson's disease CDP-Choline can be used, which is the precursor of dopamine. CDP-Choline can be given because it can cross the blood-brain barrier.

Dopamine has many functions in the brain, including important roles:

• Attention
• Behavior
• Cognition
  
• Inhibition of Prolactin Production (involved in lactation)
  
• Learning
  
• Mood
  
• Motivation and Reward
  
• Sleep
  
• Voluntary movement

Dopaminergic neurons (i.e., neurons whose primary neurotransmitter is dopamine) are present chiefly in the ventral tegmental area (VTA) of the midbrain, the substantia nigra pars compacta, and the arcuate nucleus of the hypothalamus.

Dopamine Teaching Signal

In life, we learn to repeat behaviors that lead to maximize rewards. Dopamine is therefore believed to provide a teaching signal to parts of the brain responsible for acquiring new behavior. Temporal difference learning provides a computational model describing how the prediction error of dopamine neurons is used as a teaching signal.

Age-related decreases in brain dopamine activity are associated with a decline in motor function and may also contribute to impaired performance on tasks that involve frontal brain regions. Interventions that enhance dopamine activity may improve performance and quality of life for the elderly. The fact that correlations remained significant after age effects were partialed out suggests that dopamine activity may influence motor and cognitive performance irrespective of age.

CDP-choline, Cytidine 5'-diphosphocholine or citicoline, is an essential intermediate in the biosynthetic pathway of the structural phospholipids of cell membranes, especially in that of phosphatidylcholine.

Oral Administration

CDP-choline releases its two principle components, cytidine and choline. When administered orally, it is absorbed almost completely, and its bioavailability is approximately the same as when administered intravenously.

Biopathways

Once absorbed, the cytidine and choline disperse widely throughout the organism, cross the blood-brain barrier and reach the central nervous system, where they are incorporated into the phospholipid fraction of the membrane and microsomes.

CDP-choline activates the biosynthesis of structural phospholipids in the neuronal membranes, increases cerebral metabolism and acts on the levels of various neurotransmitters. Thus, it has been experimentally proven that CDP-choline increases noradrenaline, stimulates tyrosine hydroxylase activity and dopamine levels in the central nervous system, which increases in brain acetylcholine.

Neuroprotective

Due to these pharmacological activities, CDP-choline has a neuroprotective effect in situations of hypoxia and ischemia, as well as improved learning and memory performance in human and animal models of brain aging.

Stimulating Mitochondrial Activity

Furthermore, it has been demonstrated that CDP-choline restores the activity of mitochondrial ATPase and of membranal Na+/K+ ATPase, inhibits the activation of phospholipase A2 and accelerates the reabsorption of cerebral edema in various experimental models.

CDP-choline is safe, as toxicological tests have shown; it has no serious effects on the cholinergic system and it is perfectly tolerated. These pharmacological characteristics, combined with CDP-choline's mechanisms of action, suggest that this nutrient may be suitable for the treatment of cerebral vascular disease, head trauma of varying severity and cognitive disorders of diverse etiology.

Head Trauma

In studies carried out on the treatment of patients with head trauma, CDP-choline accelerated the recovery from post-traumatic coma and the recuperation of walking ability, achieved a better final functional result and reduced the hospital stay of these patients, in addition to improving the cognitive and memory disturbances which are observed after a head trauma of lesser severity and which constitute the disorder known as postconcussion syndrome

Acute Cerebral Vascular Disease.

In the treatment of patients with acute cerebral vascular disease of the ischemic type, CDP-choline accelerated the recovery of consciousness and motor deficit, attaining a better final result and facilitating the rehabilitation of these patients.

Senile Cognitive Impairment

The other important use for CDP-choline is in the treatment of senile cognitive impairment, which is secondary to degenerative diseases (e.g., Alzheimer's disease) and to chronic cerebral vascular disease. In patients with chronic cerebral ischemia, CDP-choline improves scores on cognitive evaluation scales, while in patients with senile dementia of the Alzheimer's type, it slows the disease's evolution.

Parkinson's disease

Beneficial neuroendocrine, neuroimmunomodulatory and neurophysiological effects have been described. CDP-choline has also been shown to be effective as co-therapy for Parkinson's disease.