title: Use of a maze to detect cognitive dysfunction in a porcine model of hypothermic circulatory arrest.
abstract: BACKGROUND
  Hypothermic circulatory arrest (HCA) can result in cognitive impairment not reflected by histopathology or gross neurologic observation. We tested the sensitivity of two multi-room maze tasks in detecting cerebral dysfunction after HCA in pigs.
  
  
  METHODS
  Twenty-seven pigs were studied, divided between two tasks. 13 underwent 90 minutes HCA at 20 degrees C and were trained from postoperative day (POD) 7; 14 were unoperated controls. The maze includes a holding area, 8 rooms, and a center hallway. One piece of apple is placed in each baited room on each of 10 days of learning evaluation. After a pig enters a room, doors to all other rooms close, and the pig must return to the holding area. In task 1, 6 of 8 rooms were baited, and each day's session ended when each baited room had been entered, or after 20 trials. In task 2, initially only the right- or left-sided rooms were baited. Pigs were evaluated each day until they entered 4 baited rooms, or for 15 trials; the process was then repeated, baiting the other side.
  
  
  RESULTS
  Intraoperative physiology and postoperative recovery showed no differences between task 1 or 2 pigs. Task 1 did not distinguish between control and HCA groups (p = 0.5), but task 2 revealed significantly (p = 0.04) better learning in controls.
  
  
  CONCLUSIONS
  The significantly poorer performance of pigs after HCA suggests that the reversal of baited rooms in task 2 provides the sensitivity to detect cognitive dysfunction. The maze is a promising tool to investigate in pigs the mild cerebral damage often seen after HCA.
authors.affiliation: Department of Cardiothoracic Surgery, Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Hagl
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Weisz
authors.forename: Nawid
authors.initials: N
authors.lastname: Khaladj
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Griepp
authors.forename: David
authors.initials: D
authors.lastname: Spielvogel
authors.forename: Bo-Yi
authors.initials: BY
authors.lastname: Yang
authors.forename: Richard A
authors.initials: RA
authors.lastname: de Asla
authors.forename: Carol A
authors.initials: CA
authors.lastname: Bodian
authors.forename: Randall B
authors.initials: RB
authors.lastname: Griepp
mesh_terms: D000818:Animals; D002315:Cardiopulmonary Bypass; D003072:Cognition Disorders / Q000175:diagnosis*; D004195:Disease Models, Animal; D006324:Heart Arrest, Induced / Q000009:adverse effects*; D018782:Maze Learning; D013552:Swine