Paternal Behavioral Plasticity in mice

Abstract

Behavioral plasticity is an ability to modify an individual’s behavior in response to change of environmental factors. Because the costs and benefits of parental decisions at any given moment in time are sensitive to a variety of environmental factors, parental care behavior is considered an appropriate subject to study behavioral plasticity. This study reports that laboratory mice display paternal behavioral plasticity where sire modifies its care behavior in response to changes in social environmental factor, such as partner effort. Phospholipase Cβ1 (PLCβ1) is distributed in the forebrain areas and is activated by Gq11 coupled to G protein-coupled receptors, including oxytocin and vasopressin receptors. PLCβ1 knockout (KO) female mice displayed normal maternal care behavior until about 12 hrs postpartum (pp), but later (after 18 hrs pp) neglected the pups, so that all pups died within 2 days. However, almost all pups survived when wildtype (WT) sire was present, suggesting that paternal behavior may contribute to the pup survival in the KO dam condition. We therefore monitored sire’s behavior under KO dam or WT dam condition in order to examine the effect of partner on paternal behavior. The total paternal behavior was significantly higher in KO dam condition compared to that in WT dam condition. In pup retrieval task, sires in KO dam condition finished retrieval significantly faster than those in WT dam condition during the period after 18 hrs pp, but not before 12 hrs pp. These results demonstrate that paternal behavior was modified in response to reduced partner effort. Currently we are examining the expression patterns of relevant signal molecules (CRF, DARPP-32) in paternal brain during the postpartum period to explore the paternal plasticity mechanism.