[Abstract Title]. - Society for Neuroscience

Authors: *K. J. LEE 1 , H.-J. KIM 1 , H.-J. KIM 1 , S.-W. KANG 1 , S.-G. SHIN 1 , S.-H. CHOI 1 , K.-
H. SHIN 1 , M.-S. LEE 2 ;
1 Dept of pharmacology, Korea Univ, college of medicine, Seoul, Republic of Korea; 2 Psychiatry,
Korea university, Seoul, Republic of Korea
Abstract: Dysregulation of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR)
has been implicated in depression and antidepressant effect. Despite the fact that chronic stress
or repeated antidepressant treatment changes GR or MR expression in the hippocampus, less is
known about the effect of chronic mild stress (CMS), one of the animal models of depression, on
the changes in GR and MR as well as the antidepressant pretreatment effect on these changes. To
address this issue, we observed the effects of venlafaxine pretreatment on CMS-induced changes
in immunoreactivities of GR and MR in the hippocampus. Venlafaxine, serotonin and
norepinephrine reuptake inhibitor, is known for its rapid and effective antidepressant activity.
CMS significantly increased GR immunoreactivity in granule cell layer of hippocampus (GCL)
and venlafaxine pretreatment abolished the CMS-induced increase in GR-IR. Similar changes in
GR-IR by venlafaxine pretreatment and CMS were observed in the CA1 of hippocampus. On the
contrary, CMS slightly decreased MR immunoreactivity (MR-IR) in the CA1 and these changes
were recovered by venlafaxine pretreatment. Interestingly, venlafaxine pretreatment alone
significantly increased MR-IR in the CA1. In addition to changes in corticosteroid receptors,
CMS significantly increased plasma corticosterone levels, but venlafaxine pretreatment prior to
CMS did not significantly affect these changes. These results show that CMS significantly
increased and decreased GR and MR in the hippocampus, respectively and that these changes
were restored to normal by venlafaxine pretreatment. Thus, the present study suggests that
venlafaxine may exert antidepressant effect through opposing the chronic stress-induced changes
in GR and MR in the hippocampus.
Disclosures: K.J. Lee, None; H. Kim, None; H. kim, None; S. Kang, None; S. Shin, None; S.
Choi, None; K. Shin, None; M. Lee, None.
Poster
282. Stress and the Brain: Cellular Actions of Stress
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 282.17/OO24
Topic: E.06.d. Cellular actions of stress
Support: MH 41256
5P50MH58911