Chronic mild stress decreases survival, but not proliferation, of new-born cells in adult rat hippocampus.
New-born cells continue to proliferate and survive to become mature granule cells in adult rat hippocampus. Although this process, known as neurogenesis, is inhibited by acute stress, it is not clear whether chronic stress affects neurogenesis. To determine whether chronic mild stress (CMS) influences neurogenesis in the adult rat hippocampus, male Sprague-Dawley rats were exposed to CMS and administered bromodeoxyuridine (BrdU) before or after CMS to observe the survival/differentiation or proliferation of new-born cells, respectively. In addition, we measured brain-derived neurotrophic factor (BDNF) mRNA in the granule cell layer (GCL) of the hippocampus, because BDNF is known to play an important role in the survival of new-born cells. CMS significantly decreased the survival of new-born cells in the GCL, but did not influence the proliferation or differentiation of new-born cells. CMS did not affect the proliferation and survival of new-born cells in the hilus. In addition, CMS did not change BDNF mRNA levels in the GCL. These results demonstrate that CMS reduces the survival of new-born cells but not of their proliferation, suggesting that repeated mild stress could influence a part of neurogenesis, but not the whole part of neurogenesis. These results raise the possibility that the survival of new-born cells may be suppressed in the presence of normal BDNF mRNA levels in GCL.
Lee
Kuem-Ju
KJ
Graduate School of Biomedical Sciences, Korea University College of Medicine, Seoul 136-705, Korea.
Kim
Sung-Jin
SJ
Kim
Suk-Won
SW
Choi
Song-Hyen
SH
Shin
You-Chan
YC
Park
Sang-Ha
SH
Moon
Bo-Hyun
BH
Cho
Eujin
E
Lee
Min-Soo
MS
Choi
Sang-Hyun
SH
Chun
Boe-Gwun
BG
Shin
Kyung-Ho
KH
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000008:administration & dosage*; D064026:Calbindins; D049109:Cell Proliferation; D002470:Cell Survival; D016650:Fluorescein-5-isothiocyanate; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development / Q000473:pathology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D012235:Rhodamines; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D013312:Stress, Physiological / Q000473:pathology / Q000503:physiopathology*
D019208:Brain-Derived Neurotrophic Factor; D064026:Calbindins; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; D012235:Rhodamines; D064030:S100 Calcium Binding Protein G; D001973:Bromodeoxyuridine; D016650:Fluorescein-5-isothiocyanate