Unilateral odor deprivation: differential effects due to time of treatment

Rats were unilaterally deprived of odor stimulation by surgically sealing one naris 1, 30 or 60 days after birth. Thirty days later the laminar volumes of the olfactory bulb ipsilateral to the occluded naris were compared with those ipsilateral to the normal side. Deprivation from days 1-30 resulted in approximately 25% reductions in "deprived" bulb size, corroborating results reported by others. Altered experience at older ages had little effect on laminar volume suggesting that deprivation does not produce atrophy per se, but interacts with early developmental processes to result in differential bulb size.