In the first study to comprehensively track how different types of brain cells respond to the mutation that causes Huntington’s disease (HD), MIT neuroscientists found that a significant cause of death for an especially afflicted kind of neuron might be an immune response to genetic material errantly released by mitochondria, the cellular components that provide cells with energy. In different cell types at different stages of disease progression, the researchers measured how levels of RNA differed from normal in brain samples from people who died with Huntington’s disease and in…