Description
ALS is a uniformly fatal neurodegenerative disease in which motor neurons in the spinal cord and brain stem are selectively lost. Individual motor - groups of motor neurons innervating single muscles - show widely varying degrees of disease resistance: in the final stages of ALS, nearly all voluntary movement is lost but eye movement and eliminative and sexual functions remain relatively unimpaired. These functions are controlled by motor neurons of the oculomotor (III), trochlear (IV) and abducens (VI) nuclei in the midbrain and brainstem, and by Onufs nucleus in the lumbosacral spinal cord, respectively. Correspondingly, in ALS autopsies the oculomotor and Onufs nuclei are almost completely preserved. We used microarray profiling of isolated wildtype mouse motor neurons to identify genes whose expression was characteristic of both oculomotor and Onufs nuclei but not of vulnerable lumbar spinal neurons, or vice versa.