The SI box was wiped with towels dampened with a

A total of 54 litters were used to generate 225 male and female offspring to serve as experimental subjects. An additional 32 untreated litters provided the 225 social interaction partners. To avoid potential litter bias no more than one male and one female from a litter was allotted to each treatment condition per testing age [49]. Animals were divided into two distinct cohorts. One cohort underwent social interaction (SI) testing at P28, followed by gap crossing at P31 and elevated plus maze testing at P35; a second cohort of animals underwent SI testing and gap crossing at P42.
2.4. Measurement of whisker length
On P42, a sub-set of 70 rats were anesthetized with 3% isoflurane (Vet One, Boise, ID) until unconscious, and C-row whiskers (C1 to C5) were plucked from the BV6 of the muscle on both the clipped and non-clipped sides. The length (mm) for each whisker from the base to the tip of the whisker shaft was measured and recorded.
2.5. Social interaction test
On P28 or P42 rats were transported to a dimly lit testing room where they habituated to the room for 2 h before undergoing testing in a modified social interaction (SI) paradigm [9], [50] and [51]. The SI apparatus was a perspex box (30 cm × 20 cm × 20 cm; Binghamton Plate Glass, Binghamton, NY). This box included a clear partition that divided stimulus into two equal halves with a semicircular hole (7 cm × 5 cm) in the middle, which allowed the animals to temporarily avoid contact by moving between compartments [9] and [50]. Each test comprised a 10 min interaction between an experimental animal and an untreated play partner. Animals were matched for weight (weight difference no greater than ± 10 g), age, and sex.