The long-lasting effects of cross-fostering on the emotional behavior in ICR mice.
Early-life stress during the postnatal period could precipitate long-lasting alterations in the functional properties underlying emotional expression in humans, but how the psychological stress of cross-fostering affects emotional behavior during adulthood in mice remains primarily unknown. The purpose of the present study was to examine the long-term effects of cross-fostering on the emotional behavior and cognitive functions of ICR offspring in adulthood. Cross-fostering was performed from postnatal day 7 for 3 weeks. Mice were divided into three groups: (1) biological group: pups born from ICR dams fostered by their original mothers; (2) in-foster group: pups born from ICR dams but adopted by other ICR dams and (3) cross-foster group: ICR pups adopted by C57 dams. ICR mice were subjected to behavioral experiments at the age of 8 weeks. Emotional behaviors in the cross-fostered mice were significantly altered in the open-field, elevated plus maze and forced swimming tests, as well as social interaction tests. However, the cross-fostered mice showed normal memory function in the Y-maze and novel object recognition tests. The contents of serotonin metabolisms were decreased in the prefrontal cortex and hippocampus indicated the deficit of serotoninergic neuronal function by cross-fostering. These findings suggested that the early-life stress of cross-fostering induced long-lasting emotional abnormalities, which might be possibly related to alterations of serotonin metabolisms.
Lu
Lingling
L
Department of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Meijo University, Japan.
Mamiya
Takayoshi
T
Lu
Ping
P
Niwa
Minae
M
Mouri
Akihiro
A
Zou
Li-Bo
LB
Nagai
Taku
T
Hiramatsu
Masayuki
M
Nabeshima
Toshitaka
T
D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D015306:Biogenic Monoamines / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D003071:Cognition / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000378:metabolism; D007398:Interpersonal Relations; D008297:Male; D008426:Maternal Deprivation; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D009043:Motor Activity / Q000502:physiology; D017397:Prefrontal Cortex / Q000378:metabolism; D011247:Pregnancy; D012701:Serotonin / Q000378:metabolism; D013315:Stress, Psychological / Q000150:complications* / Q000209:etiology / Q000503:physiopathology*; D013997:Time Factors
D015306:Biogenic Monoamines; D012701:Serotonin