Changes in three-dimensional arterial spin labeling perfusion imaging of the hippocampus in depressive Itpr2-/- mice

Abstract

To study the behavioral changes of inositol 1, 4, 5-trisphosphate receptor type 2 knockout (Itpr2-/- mice) and investigate the blood perfusion changes in the hippocampus using three-dimensional arterial spin labeling (3D-ASL). 28 Itpr2-/- mice and 20 wild-type mice were assessed for depressive phenotype using behavioral tests (including sucrose consumption test, tail suspension test, forced swimming test and open field test). 15 Itpr2-/- mice and 14 wild-type mice were randomly selected for 3D-T2WI imaging of the whole brain and 3D-ASL imaging of the middle hippocampal layer, and cerebral blood flow (CBF) of the middle hippocampal layer was calculated. ITK-SNAP was used to delineate the bilateral hippocampal area and measure the average CBF value. Compared with the wild-type mice, Itpr2-/- mice exhibited a distinct depressive phenotype with significantly decreased sucrose preference (P < 0.05) and increased immobile time in tail suspension test (P < 0.05) and forced swimming test (P < 0.01), without obvious changes in the performance in open field test (P > 0.05). Significantly decreased mean CBF values were found in the left and right hippocampus of Itpr2-/- mice as compared with the wild-type mice (left: 73.30 ±5.609 vs 95.77±5.095; right: 73.53±5.700 vs 100.5±4.696; bilateral means: 73.42±5.607 vs98.12±4.754; P < 0.01). Itpr2 deficiency can cause depressive phenotype and affect the cerebral blood flow in the hippocampus of mice.