Reduced long-term memory in a rat model of 8 minutes ventricular fibrillation cardiac arrest: a pilot trial.
BACKGROUND
Evaluating beneficial effects of potential protective therapies following cardiac arrest in rodent models could be enhanced by exploring behavior and cognitive functions. The Morris Water Maze is a well-known cognitive paradigm to test spatial learning and memory.


RESULTS
Behavioral testing with the Morris Water Maze in Sprague-Dawley rats (300 ± 25 g) resuscitated after 8 min of ventricular fibrillation cardiac arrest was carried out 5 and 12 weeks after cardiac arrest (CA) and compared to results of naïve rats (CONTROL). At 5 weeks, within each group latency time to reach the hidden platform (reflecting spatial learning) decreased equally from day 1 to 4 (CA: 105.6 ± 8.2 vs. 8.9 ± 1.2 s, p < 0.001;


METHODS
75.5 ± 13.2 vs. 17.1 ± 4.5, p < 0.001) with no differences between groups (p = 0.138). In the probe trial 24 h after the last trial, time spent in the target sector (reflecting memory recall) within each group was significantly longer (CA: 25 ± 1.3;


METHODS
24.7 ± 2.5 s) than in each of the three other sectors (CA: 7.7 ± 0.7, 14.3 ± 2.5, 8.4 ± 0.8 and


METHODS
7.8 ± 1.2, 11.7 ± 1.5, 10.3 ± 1.6 s) but with no significantly differences between groups. Seven days later (reflecting memory retention), control group animals remained significantly longer in the target sector compared to every other sector, whereas the cardiac arrest group animals did not. Even 12 weeks after cardiac arrest, the single p values showed that the control animals displayed a trend to perform better than the resuscitated animals.


CONCLUSIONS
Memory recall was impaired early after 8 min of ventricular fibrillation cardiac arrest and might be a more valuable tool for cognitive testing than learning recall after global ischemia due to cardiac arrest.
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Wolfgang
W
Weihs
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Alexandra-M
AM
Warenits
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Florian
F
Ettl
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Ingrid A M
IA
Magnet
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.|Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Wien, Austria.
Ursula
U
Teubenbacher
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Andreas
A
Hilpold
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Andreas
A
Schober
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Christoph
C
Testori
Department of Anaesthesiology, General Intensive Care and Pain Management, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Akos
A
Tiboldi
Core Center of Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Katharina Tillmann
KT
Mag
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.
Michael
M
Holzer
Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Wien, Austria.
Sandra
S
Hoegler
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria.|II Medical Department of Cardiology, Hanusch Hospital, Vienna, Heinrich-Collin-Straße 30, 1140, Wien, Austria.
Andreas
A
Janata
Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Wien, Austria. fritz.sterz@meduniwien.ac.at.
Fritz
F
Sterz
D000818:Animals; D016887:Cardiopulmonary Resuscitation; D006323:Heart Arrest / Q000150:complications*; D008297:Male; D018782:Maze Learning; D057567:Memory, Long-Term; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014693:Ventricular Fibrillation
Behavioral testing; Cardiac arrest; Cardiopulmonary resuscitation; Induced; Morris Water Maze; Rats