Fig. 5.

Frequency of ultrasonic vocalization during social isolation in Nrg1 mouse pups. No significant differences were found between the wild-type and heterozygous pups at any age of testing. Mean values for Nrg1+/+ and Nrg1+/− pups within each litter were used for analysis (rather than individual pup scores). Data shown are overall means (± SEM) calculated from the litter means (+/+ and +/−) for a 5-min test. N = 7–10 L at each time point. Data from one wild-type pup with a very high number of vocalizations (> 500) on postnatal day 5 were removed from the analysis