Ionis Pharmaceuticals 1 article published in JoVE Neuroscience Intrathecal Delivery of Antisense Oligonucleotides in the Rat Central Nervous System Yi Chen*1, Curt Mazur*2, Yi Luo*1, Linhong Sun1, Mingdi Zhang1, Alex McCampbell1, Giulio Srubek Tomassy1 1Biogen, Inc., 2Ionis Pharmaceuticals Here, we describe a method for delivering drugs to the rat central nervous system by implanting a catheter into the lumbar intrathecal space of the spine. We focus on the delivery of antisense oligonucleotides, though this method is suitable for delivery of other therapeutic modalities as well.