Constraint of the mother with pups restores some aspects of the maternal behavior of mutant staggerer mice.

Under normal breeding conditions, the female staggerer is unable to rear her pups. She does not care for them, does not suckle, never retrieves them, and she may even reject them. Most of the staggerer mother's offspring die within the first day. By forcing the mother to remain with foster pups for 24 hours immediately after deliver, and thereafter replacing them with older pups, maternal behavior can partly be restored. Although badly cleaned and not retrieved, 67 percent of the staggerer offspring survived under these conditions. The results obtained demonstrate considerable environmentally induced plasticity in the behavior of the staggerer mouse.