Table 1.

Representative vocalization studies in mutant mouse models

Mouse model	Ultrasonic vocalizations	Age range	Description	References
FOXP2 knock out mice	Decreased emission rate	PND 6	Decrease emission rate in (−/+) mice, no emission in(−/−) mice. Both whistles and clicks are reduced in (−/+) mice	Shu et al, 2005
Ts65Dn (Down syndrome mouse model)	Delayed ontogenetic profile	PNDs 3 - 13	Ultrasonic vocalization profile was delayed by 4 days. Peak expression of USVs was observed on PND 9 in Ts65Dn mice, on PND 5 in 2n control mice	Holtzman et al. 1996
MeCP2 (Rett syndrome mouse model)	Increased emission rate	PNDs 3 -12	Increased emission rate since PND 5 in hemizygous null male mice, since PND 7 in heterozygous females	Pickers et al. 2006
Reelin	Decreased emission rate	PNDs 3 - 9	Decreased emission rate throughout the first postnatal week.	Laviola et al. 2006; Ognibene et al. 2007
FGF17	Decreased emission rate	PND 8	Decreased emission rate during two repeated isolation periods	Scearce-Levie et al. 2007
AVP1b receptor Knock out mice	Lack of maternal potentiation effect in knockout and heterozygous	PND 9	Increased emission rate (maternal potentiation) after a brief reunion with the mother in wt controls, not in heterozygous and knockout; increased call duration in all groups (wt, heterozygous and knockout).	Scattoni et al. 2008