A. Gonzalez et al., Intergenerational effects of complete maternal deprivation and replacementstimulation on maternal behavior and emotionality in female rats, DEVELOP PSY, 38(1), 2001, pp. 11-32
The present study investigated the effects of early rearing experiences on
the development of maternal behavior in Sprague-Dawley female rats. Pups fr
om individual litters were assigned to four different groups on Day 3 of li
fe. From days 4 to 20 of life, these were reared artificially without mothe
r and receiving minimal "licking-like" tactile stimulation (AR-MIN), or max
imal stimulation (AR-MAX) or were reared with their mothers (MR-CONTROL and
MR-SHAM). At 70-100 days all AR and MR animals were mated and then observe
d with their own offspring, culled to eight pups. After maternal testing op
en-field tests were conducted. The female offspring in these litters (all r
aised by their MR and AR mothers) were reared to adulthood and then observe
d interacting with their offspring.
Results show that in adulthood AR mothers engaged in significantly fewer pu
p-retrievals and less pup-licking (genital and body), and crouching, but si
gnificantly more non-maternal tail-chasing, digging, and hanging/climbing.
As well, they were more active in the open field. Comparisons between the t
wo AR groups and the MR groups, showed that most of the differences were be
tween the AR-MIN and MR groups, with the AR-MAX animals showing levels of b
ehavior between the two, and differing from neither Analyses of covariance
indicated that early experience and adult emotional behavior both influence
adult maternal behavior but their effects are independent of one another.
A cross-generational effect of artificial rearing was also found. Daughters
of AR and MR mothers that were observed after the birth of their own litte
rs in adulthood showed a pattern of behavior that mimicked the pattern show
n by their mothers.
These results are discussed in terms of the variety of possible behavioral,
endocrine, and neurochemical mechanisms that mediate the effects of early
experiences on adult maternal behavior (C) 2001 John Wiley & Sons, Inc.