Research reportBrief social isolation in early adolescence affects reversal learning and forebrain BDNF expression in adult rats

Isolation rearing produces significant behavioral and neurochemical dysregulations in rodents. However, few studies have examined the effects of short-term isolation rearing during puberty compared to chronic social isolation from weaning to adulthood. In this study, we subjected weaning rats to a brief two-week social isolation and then re-socialized them until adulthood. We found that early isolation rearing affected reversal learning without interfering with spatial learning in the Morris water maze. We also found that brain-derived neurotrophic factor (BDNF) protein expression was increased in the medial prefrontal cortex (mPFC) but was decreased in the nucleus accumbens (NAc), CA1 and dentate gyrus of the hippocampus in isolation-reared rats. Together, our findings support the use of adolescent social isolation as a rodent model to study brain and behavior abnormalities induced by early environmental interruptions.

► This study shows that early isolation rearing (postnatal day 21-34) impairs reversal learning but not spatial acquisition learning in Morris water maze of adult rats. ► This study shows that early isolation rearing increases brain derived neurotrophic factor expression in prefrontal cortex while decreases its expression in hippocampus and nucleus accumbens. ► This study advances the use of isolation rearing as an animal model to study environmental disruption induced behavioral and brain dysregulations.