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Effects of chronic mild stress in female bax inhibitor-1-gene knockout mice.

Sui ZY, Chae HJ, Huang GB, Zhao T, Shrestha Muna S, Chung YC - Clin Psychopharmacol Neurosci (2012)

Bottom Line: Significant decreases in sucrose consumption and increases in immobility time in the FST were observed in both stress groups compared with the non-stress groups.These results suggest that BI-1 may play role in protecting against the depressogenic effects of CMS in the short term, but not in the long term.Further study is required to deepen understanding of the role of BI-1 in protecting against depression.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Chonbuk National University Medical School & Institute for Medical Sciences, Jeonju, Korea. ; Department of Psychiatry, Chonbuk National University Hospital & Research Institute of Clinical Medicine, Jeonju, Korea.

ABSTRACT

Objective: The anti-apoptotic protein Bax inhibitor-1 (BI-1) is a regulator of apoptosis linked to endoplasmic reticulum (ER) stress, and BI-1(-/-) mice exhibit increased sensitivity to tissue damage. The purpose of this study was to investigate the role of BI-1 in the pathogenesis of chronic mild stress (CMS)-induced depression-like behaviors in BI-1(-/-) mice.

Methods: We delivered CMS for 2 or 6 weeks in BI-1-knockout and wild-type mice. Control groups of BI-1-knockout and wild-type mice were left undisturbed. The measured parameters were sucrose consumption at weeks 1, 2, 3, 4, 5, and 6, spontaneous locomotion, and a forced swimming test (FST) at weeks 2 and 6.

Results: Significant decreases in sucrose consumption and increases in immobility time in the FST were observed in both stress groups compared with the non-stress groups. Interestingly, at week 2, but not at week 6, BI-1(-/-)-stress mice showed less sucrose intake and greater immobility time than did BI-1(+/+)-stress mice.

Conclusion: These results suggest that BI-1 may play role in protecting against the depressogenic effects of CMS in the short term, but not in the long term. Further study is required to deepen understanding of the role of BI-1 in protecting against depression.

No MeSH data available.


Related in: MedlinePlus

Experiment design of the study. SCT, sucrose consumption test. *Behavior tests include locomotion and forced swimming test.
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Figure 1: Experiment design of the study. SCT, sucrose consumption test. *Behavior tests include locomotion and forced swimming test.

Mentions: After 10 days of initial acclimation to the laboratory, the mice were trained to drink a sucrose solution. Mice were exposed to two standard drinking bottles on alternating nights during week 1; one bottle contained 2.5% sucrose and the other held tap water. After this preliminary phase, mice were food and water deprived for 8 hours and then exposed to the sucrose solution and water from 18:00 until 09:00 to measure sucrose consumption. Three baseline sucrose consumption tests were performed, separated by 3 days. Each group of BI-1+/+ and BI-1-/- mice was divided into two groups, control and stress groups, matched for sucrose consumption and body weight. This resulted in four different groups: BI-1+/+ control and stress groups (n=4-6) and BI-1-/- control and stress groups (n=4-6). The stress group was exposed to CMS, and the control group was left unchallenged. We initially conducted one experiment with a 6-week CMS treatment (experiment 1). Significant results were obtained after 2 weeks, so we conducted an additional short experiment with a 2-week CMS treatment (experiment 2). Behavioral tests, spontaneous locomotor activity, and a forced swimming test (FST), were performed between 08:00 and 14:00 after 2 and 6 weeks of exposure to CMS. No stressors were applied 15 hours before the tests (Fig. 1).


Effects of chronic mild stress in female bax inhibitor-1-gene knockout mice.

Sui ZY, Chae HJ, Huang GB, Zhao T, Shrestha Muna S, Chung YC - Clin Psychopharmacol Neurosci (2012)

Experiment design of the study. SCT, sucrose consumption test. *Behavior tests include locomotion and forced swimming test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569165&req=5

Figure 1: Experiment design of the study. SCT, sucrose consumption test. *Behavior tests include locomotion and forced swimming test.
Mentions: After 10 days of initial acclimation to the laboratory, the mice were trained to drink a sucrose solution. Mice were exposed to two standard drinking bottles on alternating nights during week 1; one bottle contained 2.5% sucrose and the other held tap water. After this preliminary phase, mice were food and water deprived for 8 hours and then exposed to the sucrose solution and water from 18:00 until 09:00 to measure sucrose consumption. Three baseline sucrose consumption tests were performed, separated by 3 days. Each group of BI-1+/+ and BI-1-/- mice was divided into two groups, control and stress groups, matched for sucrose consumption and body weight. This resulted in four different groups: BI-1+/+ control and stress groups (n=4-6) and BI-1-/- control and stress groups (n=4-6). The stress group was exposed to CMS, and the control group was left unchallenged. We initially conducted one experiment with a 6-week CMS treatment (experiment 1). Significant results were obtained after 2 weeks, so we conducted an additional short experiment with a 2-week CMS treatment (experiment 2). Behavioral tests, spontaneous locomotor activity, and a forced swimming test (FST), were performed between 08:00 and 14:00 after 2 and 6 weeks of exposure to CMS. No stressors were applied 15 hours before the tests (Fig. 1).

Bottom Line: Significant decreases in sucrose consumption and increases in immobility time in the FST were observed in both stress groups compared with the non-stress groups.These results suggest that BI-1 may play role in protecting against the depressogenic effects of CMS in the short term, but not in the long term.Further study is required to deepen understanding of the role of BI-1 in protecting against depression.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Chonbuk National University Medical School & Institute for Medical Sciences, Jeonju, Korea. ; Department of Psychiatry, Chonbuk National University Hospital & Research Institute of Clinical Medicine, Jeonju, Korea.

ABSTRACT

Objective: The anti-apoptotic protein Bax inhibitor-1 (BI-1) is a regulator of apoptosis linked to endoplasmic reticulum (ER) stress, and BI-1(-/-) mice exhibit increased sensitivity to tissue damage. The purpose of this study was to investigate the role of BI-1 in the pathogenesis of chronic mild stress (CMS)-induced depression-like behaviors in BI-1(-/-) mice.

Methods: We delivered CMS for 2 or 6 weeks in BI-1-knockout and wild-type mice. Control groups of BI-1-knockout and wild-type mice were left undisturbed. The measured parameters were sucrose consumption at weeks 1, 2, 3, 4, 5, and 6, spontaneous locomotion, and a forced swimming test (FST) at weeks 2 and 6.

Results: Significant decreases in sucrose consumption and increases in immobility time in the FST were observed in both stress groups compared with the non-stress groups. Interestingly, at week 2, but not at week 6, BI-1(-/-)-stress mice showed less sucrose intake and greater immobility time than did BI-1(+/+)-stress mice.

Conclusion: These results suggest that BI-1 may play role in protecting against the depressogenic effects of CMS in the short term, but not in the long term. Further study is required to deepen understanding of the role of BI-1 in protecting against depression.

No MeSH data available.


Related in: MedlinePlus