Governor Mark Dayton will be sidelined for the rest of this year following spinal surgery. Dayton is undergoing an operation today at the Mayo Clinic in Rochester. The Governor is hoping to relieve a constriction in his lower back known as stenosis. The procedure will involve fusing a vertebrae in his lower back that is shifting out of alignment. A hospital spokesman says it is generally caused by normal wear-and-tear on the spine due to aging. Dayton turns 66 in a few weeks. He is scheduled to be released from the hospital by Monday and will return to St. Paul then. He plans to work from the Governor's Residence during a recuperation period.