Objective      To determine the effect of TO901317

the agonist of liver X receptor

on the number of astrocytes in hippocampal dentate gyrus (DG) and on radial processes in the dentate gyrus subgranular zone (DG-SGZ) in adult mice.       Methods      TO901317 (40 mg/kg) was intragastrically administrated to the healthy female C57B/L6 mice for 7

d. The number of GFAP positive cells and radial-like fibers in the hippocampus was detected by immunohistochemistry. The expression of LXRα

LXRβ

Klf-9

ABCA1

ABCG1 and apoE was detected by RT-PCR. The size and weight of the liver were also observed.       Results      After 1 week’s TO901317 treatment

the number of GFAP positive cells in the DG was decreased markedly (

P

<

0.05)

while the GFAP positive radial-like fiber in the SGZ was increased significantly (

P

<

0.01). No change was found in the expression of LXRα

while that of LXRβ was decreased (

P

<

0.05). The expression of Klf-9

ABCA1

ABCG1 and apoE was increased significantly after TO901317 administration (

P

<

0.05). Significant increases of the liver size and weight were observed in TO901317 group when compared with those in DMSO group  (

P

<

0.01).       Conclusion      Through LXRβ receptor

TO901317 modulates the expression of Klf-9

ABCA1

ABCG1 and apoE

and improves the outgrowth of radial-like process of astrocytes in the DG-AGZ.