Table 1.

Summary of the number of subjects employed in the behavioral tests

Experiments	Experimental groups (prenatal treatment–postnatal rearing)				Age (PND)
	SAL-SAL	SAL-POL	POL-SAL	POL-POL
1. Elevated plus maze	5♂, 5♀	6♂, 4♀	5♂, 5♀	5♂, 5♀	35
2. Open field	5♂, 5♀	6♂, 4♀	5♂, 5♀	5♂, 5♀	38
3. Fear conditioning	5♂, 5♀	6♂, 4♀	5♂, 5♀	5♂, 5♀	42–44
4. Elevated plus maze	5♂, 5♀	6♂, 4♀	4♂, 6♀	5♂, 5♀	85
5. Open field	5♂, 5♀	6♂, 4♀	4♂, 6♀	5♂, 5♀	88
6. Fear conditioning	5♂, 5♀	6♂, 4♀	4♂, 6♀	5♂, 5♀	91–93

Neonates of saline (SAL)- and PolyI:C (POL)-treated dams were cross-fostered to surrogate-rearing mothers, which had been exposed to either saline or PolyI:C during pregnancy. This yielded four experimental groups according to a two (prenatal treatment) × two (postnatal rearing) design. Experiments 1–3 assessed anxiety- and fear-related behavior when the fostered offspring reached peri-adolescence, i.e., between postnatal days (PNDs) 35 and 44. The same subjects were used for repeated testing at the indicated order. Experiments 4–6 assessed anxiety- and fear-related behavior in a new cohort of fostered offspring when they reached adulthood, i.e., at PND 85–93. Again, the same subjects were used for repeated testing at the indicated order. The offspring were derived from 16 mothers, half of which had been subjected to PolyI:C exposure during pregnancy and the other half to vehicle treatment only. All experiments included testing of male and female animals