PT  - JOURNAL ARTICLE
AU  - Xin Zhao
AU  - Hieu Tran
AU  - Holly DeRosa
AU  - Ryland C. Roderick
AU  - Amanda C. Kentner
TI  - Hidden Talents: Poly (I:C)-induced maternal immune activation improves mouse visual discrimination performance and reversal learning in a sex-dependent manner
AID  - 10.1101/2021.02.15.431275
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.02.15.431275
4099  - http://biorxiv.org/content/early/2021/04/28/2021.02.15.431275.short
4100  - http://biorxiv.org/content/early/2021/04/28/2021.02.15.431275.full
AB  - While there is a strong focus on the negative consequences of maternal immune activation (MIA) on developing brains, very little attention is directed towards potential advantages of early life challenges. In this study we utilized a polyinosine-polycytidylic acid (poly(I:C)) MIA model to test visual discrimination (VD) and reversal learning (RL) in mice using touchscreen technology. Significant sex differences emerged in that MIA improved the latency for males to make a correct choice in the VD task while females reached criterion sooner, made fewer errors, and utilized fewer correction trials in RL compared to saline controls. These surprising improvements were accompanied by the sex-specific upregulation of several genes critical to cognitive functioning, indicative of compensatory plasticity in response to MIA. In contrast, when exposed to a ‘two-hit’ stress model (MIA + loss of the social component of environmental enrichment (EE)), mice showed no evidence of anhedonia but required an increased number of PD and RL correction trials. These animals also had significant reductions of CamK2a mRNA in the PFC. Appropriate functioning of synaptic plasticity, via mediators such as this protein kinase and others, are critical for behavioral flexibility. Although EE has been implicated in delaying the appearance of symptoms associated with certain brain disorders, these findings are in line with evidence that it also makes individuals more vulnerable to its loss. Overall, with the right ‘dose’, early life stress exposure can confer at least some functional advantages, which are lost when the number or magnitude of these exposures become too great.Competing Interest StatementThe authors have declared no competing interest.