Postpartum repeated separation from pups affects the behavior and neuroendocrine parameters of mandarin vole fathers.

Repeated separation from pups results in anxiety and depression-like behaviors in mothers. This level of attachment has also been established between fathers and pups in monogamous rodents. We hypothesized that brief and lengthy separation from their pups would affect emotion, social behavior and neuroendocrine parameters in socially monogamous male mandarin voles (Microtus mandarinus). The results indicate that brief pup separation (BPS) of 15 min/day significantly reduced the percentage of time spent in the central area, total distance and total transition in open field tests. BPS resulted in increased sniffing and self-grooming in fathers, but reduced attacking and climbing. Long pup separation (LPS) of 3h/day suppressed attacking, sniffing, no-social investigating and digging in fathers, but increased time in immobile in social interaction and forced swimming tests. LPS upregulated levels of central oxytocin (OT) and vasopressin (AVP), serum corticosterone (CORT); BPS increased central OT and serum corticosterone only. These findings show that BPS and LPS are critical stressors for fathers and alter anxiety and depression-like and social behaviors in monogamous mandarin voles. These changes in behaviors may be associated with alteration in OT, AVP and CORT.