Long‐term effects of prenatal morphine exposure on maternal behaviors differ from the effects of direct chronic morphine treatment

Abstract

Previous studies have demonstrated that chronic morphine treatment of pregnant rats alters maternal behavior. Other studies have shown long-term effects of prenatal exposure to morphine, including changes in reproductive behavior in adult females. The present study investigated the effects of prenatal morphine exposure on a variety of maternal behaviors such as nursing, maternal activities, nonmaternal activities, and pup retrieval. Prenatal morphine exposure increased active and decreased passive nursing. There were no differences in maternal activities such as presence in the nest, contact with pups, grooming of pups, and/or manipulation of nest shavings. In the retrieval test, prenatally morphine-exposed mothers were faster in carrying the first pup, retrieving the first pup back to the nest, and returning all pups to the nest than prenatally saline-exposed mothers. Maternal and nonmaternal activities also were affected by the light: dark cycle. All saline- and morphine-exposed mothers nursed more, were more often in the nest, and more often in contact with greater than half of their litter during the light than the dark sessions. On the other hand, nonmaternal activities increased during the dark sessions: Mothers cared for themselves (groomed, ate) more and displayed more rearing and sniffing. Mothers spent more time resting with their eyes closed during the light sessions regardless of prenatal drug exposure. The present study demonstrated that the effect of morphine on maternal behavior is different in adult exposed and prenatally exposed mothers. While direct morphine treatment impaired maternal behaviors, prenatal morphine exposure has the opposite effect.

Effect of methamphetamine exposure during prenatal and preweaning periods lasts for generations in rats

“…When compared to our previous study (Š lamberová et al, 2005a) demonstrating increased latencies in retrieval test of mothers that were given MA during gestation and lactation, the present study examining the effect of MA on the next generation shows the opposite effect. Those generational differences are the same as in our previous work (Š lamberová et al, 2003;Š lamberová, Szilagyi, & Vathy, 2001) examining the effect of morphine on maternal behavior of two generations. In those studies (Š lamberová et al, 2001, 2003) we demonstrated that morphine when administered to female rats during their gestation increased the latency to return all the pups into the nest.…”

“…The time of observation was during the light phase of the light/dark cycle between 0800-0900 hr. A similar method was used as in our previous studies (Š lamberová, Bar, & Vathy, 2003;. During each 50-min session, each mother and her litter were observed 10 times for 5 s at 5-min intervals.…”

Ventral premammillary nucleus as a critical sensory relay to the maternal aggression network

“…Maternal behavior. Maternal care toward the pups was determined in unlesioned and PMv-lesioned dams tested for maternal aggression as previously described (41). After giving birth, dams were left with their litters, culled to eight pups on day 1 of lactation (four males and four females).…”

A Role for the Periaqueductal Gray in Switching Adaptive Behavioral Responses

“…During the 30 min trial, we observed whether the dams expressed active nursing. Active nursing was characterized when a dam was arched over the pups with her legs splayed (arched nursing) or lying over the litter without her back arched and no obvious leg extension [blanket nursing (Slamberova et al, 2003)]. Other forms of maternal responses were also recorded (i.e., grooming, retrieving, and grouping the pups).…”