Both Dopamine and Norepinephrine are chemically related, and can be converted into each other through the brain's biochemistry, and both must be present for neural-dendrite growth to proceed for new learning to occur. Lipofuscin itself has been shown to accumulate in the brain and nerve cells, killing off neurons by inhibiting dendrite expansion by blocking the flow of vital nutrients from within nerve cells. Lipofuscin age pigment forms especially rapidly in the dopamine-dependent tracts of the brain, plugging these pathways up and inhibiting Dopamine to act.
Dopamine is a neurotransmitter which affects sexuality, locomotion, mood, tissue growth and repair.
Encephalitis lethargica or sleeping sickness, Parkinson's Disease and Catatonia in Schizophrenia are known to be correlated with low Dopamine populations within the brain. Interestingly, Dopamine populations also decline with age as lipofuscin increases. Thus lipofuscin appears to both directly and indirectly inhibit Dopamine production and transmission. Dopamine also falls prey to autoxidation, producing free radicals and hydrogen peroxide which damage dopaminergic nerve receptors. Common sense suggests that ingesting hydrogen peroxide in any form as a dietary supplement of any kind is likely dangerous, therefore, promoting dopamine receptor damage throughout the Central Nervous System.