Social crowding in the night-time reduces an anxiety-like behavior and increases social interaction in adolescent mice

Group housing during adolescence has long-term effects on the adult stress response in female, but not male, zebra finches (Taeniopygia guttata)

“…Finding that adolescent group size has no immediate effect on GC secretion has corroboration from previous work in mice and guinea pigs that also show that adolescent group size has no immediate effect on basal GC concentration ( Ago et al, 2014 , Laviola et al, 2002 , Ortiz et al, 1985 , Sachser et al, 1993 ; but not Lürzel et al, 2010 ). Our work expands on this prior research to suggest that the absence of effect is not due to a limited scope of measurement (i.e.…”

“…The mechanism by which female, but not male, birds use group size to modulate stress physiology remains elusive in part because most research investigating adolescent group size effects on GC secretion have only used males (e.g. Ago et al, 2014 , Lürzel et al, 2010 , Lürzel et al, 2011 , Ortiz et al, 1985 , Sachser et al, 1993 ). The single study that has included both males and females found no sex-dependent short-term effects of group size on CORT secretion in adolescent mice and did not look for long-term effects ( Laviola et al, 2002 ).…”

“…For example, adolescent male guinea pigs ( Cavia porcellus ) housed in larger groups have a lower GC secretion in response to single housing in an unfamiliar environment compared to conspecifics reared in smaller groups ( Sachser et al, 1993 , Sachser et al, 2013 ). However, group size has also been shown to have no short-term effect on GC secretion in mice ( Mus musculus : Ago et al, 2014 , Laviola et al, 2002 ). Also in mice, adolescent group size has no long-term effects on basal GC concentration ( Ortiz et al, 1985 ).…”

“…In addition, the effects of adolescent group size and social density have largely been investigated in males (e.g. Ago et al, 2014 , Sachser et al, 1993 ), and whether sex differences occur has not been adequately tested. Male and female mice have been shown to have similar basal GC concentrations regardless of social density ( Laviola et al, 2002 ) and, like adult males, higher social density in adult females results in higher basal GC concentration in mice (e.g.…”

Anti-anhedonic effect of selective serotonin reuptake inhibitors with affinity for sigma-1 receptors in picrotoxin-treated mice

“…The elevated plus‐maze test was performed as described previously (Ago et al, ; Ota et al, ). The apparatus – consisting of two open arms (25 × 8 cm) and two enclosed arms (25 × 8 cm, surrounded by a 20‐cm‐high opaque wall) – was elevated 50 cm from the ground (BrainScience·Idea Co., Ltd., Osaka, Japan).…”