Evaluation of brain damage in a rat model of neonatal hypoxic-ischemia.
In spite of improvements in obstetric and neonatal care, hypoxic-ischemic brain damage with severe neurologic disability is still a clinical reality. A model in 7-day-old rats has been introduced to study the pathophysiology of perinatal hypoxic-ischemic brain damage. Unilateral brain damage is produced in the cerebral cortex, striatum and hippocampus, i.e. a similar distribution as is often seen in human asphyxiated neonates. In the present investigation the model was evaluated further by comparing three different methods to assess the brain damage: weighing the hemispheres, morphometry and somatosensory evoked potentials. Seven-day-old rats were subjected to unilateral carotid artery ligation followed by 2 h of hypoxia (7.7% O2 at 36 degrees C). After 2 h of hypoxic-ischemia pCO2 and pO2 decreased in mixed arterial/venous blood. The evaluation of the damage 2 weeks after the insult, demonstrated close correlation between morphometry and weighing (r = 0.836, P less than 0.01). The amplitude of evoked potentials correlated to the other parameters (r = 0.814, P less than 0.01 and r = 0.824, P less than 0.01 respectively) and displayed a greater relative attenuation than the other methods but with a more pronounced variability. These results indicate that the degree of brain damage can be assessed by weighing for screening purposes.
Andiné
P
P
Institute of Neurobiology, University of Göteborg, Sweden.
Thordstein
M
M
Kjellmer
I
I
Nordborg
C
C
Thiringer
K
K
Wennberg
E
E
Hagberg
H
H
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D002545:Brain Ischemia / Q000150:complications*; D005073:Evoked Potentials, Somatosensory; D000860:Hypoxia / Q000150:complications*; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains