Enriched environments influence depression-related behavior in adult mice and the survival of newborn cells in their hippocampi

Satoko Takai, Ryota Hashimoto, Tsuyoshi Miyakawa, Hajime Yamanaka, Hiroshi Maeno, Keiji Wada, Hiroshi Kunugi

Research output: Contribution to journalArticle

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Abstract

Major depression is a highly prevalent mental disorder and environmental factors have been strongly implicated in its pathophysiology. Clinical studies have demonstrated that stress or depression can lead to atrophy and cell loss in the hippocampus. Studies of animal models of depression have suggested that reduced neurogenesis in the adult hippocampus might contribute to such structural changes and to the behavior of these animals. On the other hand, increased hippocampal neurogenesis can be induced by the administration of antidepressants or electroconvulsive seizure, suggesting that increased neurogenesis might be related to the treatment of depression. Thus, an enriched environment (EE), which also enhances neurogenesis, is expected to have therapeutic effects on depression-related behaviors. To investigate the effects of an EE during adulthood on these behaviors, we subjected adult mice housed in an EE for five weeks to behavioral tests. In an open field test, EE mice exhibited a decrease in the distance traveled and an increase in the amount of time spent in the center. The startle response was smaller in EE mice than in control mice. EE mice also showed reduced immobility time in a forced swim test. The immobility time in EE mice was approximately half that observed in mice treated with a tricyclic antidepressant, imipramine. In our experimental condition, increased survival of newborn cells was observed in EE mice by 5-bromo-2′-deoxyuridine (BrdU)-labeled immunohistochemistry. Double-staining of BrdU and a mature neuron marker, NeuN, revealed that the majority of surviving cells were neurons. Our results suggest that EE, which enhanced the survival of newborn neurons, shows beneficial effects on behavioral despair and habituation to a novel environment.

Original languageEnglish
Pages (from-to)69-76
Number of pages8
JournalBehavioural Brain Research
Volume180
Issue number1
DOIs
Publication statusPublished - 04-06-2007
Externally publishedYes

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Hippocampus
Cell Survival
Depression
Neurogenesis
Neurons
Startle Reflex
Deoxyuridine
Animal Behavior
Imipramine
Tricyclic Antidepressive Agents
Therapeutic Uses
Bromodeoxyuridine
Mental Disorders
Antidepressive Agents
Atrophy
Seizures
Animal Models
Immunohistochemistry
Staining and Labeling

All Science Journal Classification (ASJC) codes

  • Behavioral Neuroscience

Cite this

Takai, Satoko ; Hashimoto, Ryota ; Miyakawa, Tsuyoshi ; Yamanaka, Hajime ; Maeno, Hiroshi ; Wada, Keiji ; Kunugi, Hiroshi. / Enriched environments influence depression-related behavior in adult mice and the survival of newborn cells in their hippocampi. In: Behavioural Brain Research. 2007 ; Vol. 180, No. 1. pp. 69-76.
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Enriched environments influence depression-related behavior in adult mice and the survival of newborn cells in their hippocampi. / Takai, Satoko; Hashimoto, Ryota; Miyakawa, Tsuyoshi; Yamanaka, Hajime; Maeno, Hiroshi; Wada, Keiji; Kunugi, Hiroshi.

In: Behavioural Brain Research, Vol. 180, No. 1, 04.06.2007, p. 69-76.

Research output: Contribution to journalArticle

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