Surgery for chronic cerebral hypoperfusion

The surgical procedure for CCH was performed by 2 vessel occlusion (2VO) according to the method of our previous studies (Lee et al., 2016a; Park and Lee, 2016). In brief, the animals were anesthetized with a mixture of 2.5% isoflurane (Baxtor, Deerfield, IL, USA) in 33% oxygen and 67% nitrous oxide. Through a midline cervical incision, both common carotid arteries were exposed and ligated with 5/0 silk suture. The body (rectal) temperature was monitored with a rectal temperature probe (TR-100; Fine Science Tools, Foster City, CA, USA) and maintained using a thermometric blanket before, during and after the surgery until the animals completely recovered from anesthesia. The rats of the Sham- and DXT-Sham-groups were subjected to the same surgical procedures except that the common carotid arteries were not occluded. In case of death of experimental animals after the surgery, additional animals were added.