According to a Canadian study, brain cells in Parkinson’s disease exhaust themselves and die prematurely, burning out like an “overheating motor”.

Researchers say the findings, published in Current Biology, might help explain why only small parts of the brain are affected in the disease.

Parkinson’s is caused by a loss of nerve cells in certain areas of the brain – but why these cells are vulnerable has been a mystery.

Scientists from the University of Montreal studied the disease in mice cells.

They found, unlike other similar brain cells, neurons most often involved in Parkinson’s disease were complex and had many more branches.

The cells also had much higher energy requirements, producing more waste products as they met this need.

Researchers suggest it is the accumulation of these waste products that triggers cell death.

Prof, Louis-Eric Trudeau said: “Like a motor constantly running at high speed, these neurons need to produce an incredible amount of energy to function.

“They appear to exhaust themselves and die prematurely.”

Researchers hope this finding may help create better experimental models of Parkinson’s and identify new treatments.

They suggest, for example, that medication could one day be developed to help reduce the energy requirement of cells or increase their energy efficiency.