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.
Here, not only mass but also density becomes important. A denser planet will have more mass than another of the same size. The Earth is the denser planet in the Solar System, which means that it surface gravity is very high compared to its mass. Because of that we have a bigger surface gravity than Uranus (the earth has 9.79 m/sÂ² while Uranus has 8.87), and almost as big as Saturn and Neptune (10.44 and 11.15 respectivelly).