Functional implications of decreases in neurogenesis following chronic mild stress in mice
Neuroscience. 2007-12-01; 150(2): 251-259
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1. Neuroscience. 2007 Dec 5;150(2):251-9. Epub 2007 Sep 26.
Functional implications of decreases in neurogenesis following chronic mild
stress in mice.
Mineur YS(1), Belzung C, Crusio WE.
(1)Brudnick Neuropsychiatric Research Institute, University of Massachusetts
Medical School, 303 Belmont Street, Worcester, MA 01604, USA.
Numerous data from human and animal studies suggest that hippocampal plasticity
might be a key element in depression. However, the connection remains loose at
best and further data are needed. Human studies are of necessity limited, but
animal models can help providing further insight. Unpredictable chronic mild
stress (UCMS) is a commonly used model because it mimics depression-like
phenotypes satisfactorily. Its rationale is based on the underlying
stress-induced difficulties found in many depressed patients. We therefore
studied learning and hippocampal neurogenesis in mice from three different inbred
strains subjected to UCMS. Learning was assessed in different
hippocampus-dependent and independent tasks. The rate of survival of newly
generated brain cells was determined in behaviorally-naive animals. Results
demonstrated a dramatic reduction of surviving new brain cells in both the
hippocampus and the subventricular zone of UCMS-treated animals. This reduction
was observed both for neurons and for other cells of the hippocampus. Behavioral
data demonstrated an impairment of hippocampus-dependent learning, whereas
hippocampus-independent learning was spared. However, the specific results were
strongly dependent on strain and sex so that there does not appear to be a direct
causative relationship between the deficits in neurogenesis and behavior.
PMID: 17981399 [Indexed for MEDLINE]