REDUCED NUMBERS AND INTENSE ANTIUBIQUITIN IMMUNOSTAINING OF BOVINE MOTOR-NEURONS AFFECTED WITH SPINAL MUSCULAR-ATROPHY

Motor neurons in the spinal cord affected with bovine spinal muscular atrophy (SMA) were investigated immunohistochemically using antibodies against bovine ubiquitin. Anti-ubiquitin immunostained many chromatol ytic and swollen degenerating motor neurons in the ventral horn of the SMA-affected spinal cord. The most severely swollen cells showed a li ghtly-stained center and a strongly-stained periphery after immunostai ning. However there were many dark, shrunken neurons in a more advance d stage that showed a completely negative reaction when immunostained. Motor neuron counts differed significantly between SMA-affected and n ormal animals at the lumbar intumescence and at the fourth lumbar neur omere, but not at the brachial intumescence or the second cervical lev el.