What is a Neurones resting membrane potential and how is it maintained?

On average neurones in the body have a resting membrane potential (RMP) of -70mv. What this means is when inactive/ not excited, the inside of neurone is more negative than the outside of the neurone this is why the membrane potential is a negative value. If the inside of the neurone was more positive then the outside of the neurone then the membrane potential would be a positive value.

So how does the neurone get the inside of the cell more negative than the outside of the cell?

The membrane of any cell and the proteins it contains acts as an important barrier as to what is allowed to come into the cell and leave the cells. In the case of the neurone RMP a very important transport protein is Na/K ATPase. Physiologically, the concentration of Na+ is higher outside of the neurone than it is inside. For K+ the opposite is true, where K+ concentration is higher inside the neurone than on the outside. What Na/K ATPase does is actively transport (uses ATP) to move 3NA+ molecules out of the neurone and bring in 2K+ into the neurone, ATP is needed since these molecules are moving against their concentration gradient. Ultimately then what has happened is the inside of the neurone has lost 3 positive charges (NA+) and only gained 2 positive charges (K+), overall then leaving the inside less positive/more negative than the outside. So therefore it is because of this uneven distribution of positive charge facilitated by the NA/K ATPase that the RMP is established and maintained at a negative charge (-70mv).