A Shortage of Dopamine. Parkinson's disease occurs when nerve cells, or neurons, in an area of the brain that controls movement become impaired and/or die. Normally, these neurons produce an important brain chemical known as dopamine, but when the neurons die or become impaired, they produce less dopamine.arkinson's disease occurs when nerve cells, or neurons, in an area of the brain that controls movement become impaired and/or die. Normally, these neurons produce an important brain chemical known as dopamine, but when the neurons die or become impaired, they produce less dopamine.
Weight density is not a term. Weight is the effect of gravity on a Mass and will be less on the Moon since the moon has less mass and therefore less gravity than the Earth.Density is mass/volume and since mass is constant, density would also be constant.aking the world better, one answer at a time. Weight density is not a term. Weight is the effect of gravity on a Mass and will be less on the Moon since the moon has less mass and therefore less gravity than the Earth. Density is mass/volume and since mass is constant, density would also be constant.
However they are very different worlds. Mercury is over 40 percent larger than the moon, and much more massive and denser than the moon. In fact, it's density is almost the same as Earth's at about 5.4 grams per cubic centimeter as opposed to the moon's 3.3 grams.