Magnetic resonance imaging under isoflurane anesthesia alters blood-brain barrier permeability and glial cell morphology during sepsis-associated encephalopathy in rats

Ibtihel Dhaya1, Marion Griton2, Jan-Pieter Konsman1

1 Univ. Bordeaux, INCIA, UMR 5287, Bordeaux, France
2 Service de Réanimation Anesthésie Neurochirurgicale, Centre Hospitalier Universitaire (CHU) de Bordeaux, Bordeaux, France

Magnetic Resonance Imaging (MRI) of rodents under anesthesia followed by histology is a very promising approach to determine what mechanisms may be underlying functional and structural changes in the brain during sepsis-associated encephalopathy (SAE). As isoflurane anesthesia is a method of choice for MRI, but has the potential to modify the blood-brain interface and glia cells, this study addressed the effect of MRI under isoflurane anesthesia on BBB integrity, COX-2 expression and glial cells activation during CLP-induced SAE in rats. CLP reduced food intake and induced deficits in the righting reflex indicating SAE. MRI under isoflurane anesthesia after laparotomy under isoflurane anesthesia reduced BBB breakdown, decreased circularity of white matter astrocytes and increased neuronal COX-2 immunoreactivity in the cortex of rodents. In addition, it annihilated CLP-induced sepsis-associated increased circularity of white matter glial cells, but without altering perivascular COX-2 induction. These findings indicate that, depending on the measure of interest, MRI under isoflurane anesthesia can modify neurovascular and glial responses and should, therefore, be interpreted with caution.