Impact of gestational cocaine treatment or prenatal cocaine exposure on early postpartum oxytocin mRNA levels and receptor binding in the rat

Abstract

Prior research reported decreased oxytocin levels in specific brain regions correlated with disruptions in maternal care following gestational cocaine treatment in rats. Similarly, prenatal exposure to cocaine impaired subsequent maternal behavior in adulthood, but behavioral alterations were not associated with decreases in oxytocin levels in the same brain regions as were found in their cocainetreated rat dams. To determine if other aspects of the oxytocin system are disrupted by cocaine treatment or prenatal exposure to cocaine during critical time points associated with maternal care, oxytocin mRNA transcription and receptor binding were examined on postpartum day two in relevant brain regions following gestational treatment with, or prenatal exposure to, either cocaine or saline. We hypothesized that oxytocin mRNA levels and receptor binding would be differentially affected by cocaine in the early postpartum period of dams and their offspring. Our findings indicate that gestational cocaine treatment resulted in significant increases in oxytocin mRNA levels in only the paraventricular nucleus of cocaine-treated dams, with almost significant increases in both generations in the supraoptic nucleus, but no significant effects of cocaine on receptor binding in either generation of dams. These findings indicate that in addition to oxytocin levels, cocaine treatment or prenatal exposure primarily affects oxytocin mRNA synthesis, with little effect on receptor binding in specific brain regions associated with maternal behavior in the early postpartum period of the rat.

Prenatal and gestational cocaine exposure: Effects on the oxytocin system and social behavior with implications for addiction

“…Oxt synthesis and release and Oxt receptor regulation are modulated by a number of signaling pathways (Gimpl and Fahrenholz, 2001; McMurray et al, 2008a). As cocaine blocks reuptake of dopamine, serotonin and norepinephrine, studies looking at drugs which similarly effect these neurotransmitter systems offer insight into selective neurotransmitter involvement in drug-induced Oxt system changes and maternal care.…”

“…A series of preclinical cross-fostering studies was performed to better understand the contribution of prenatal exposure and an early-life environment of rearing by a drug-exposed mother. These studies often highlighted the combined exposure caused the greatest disruptions (Johns et al, 2007; 2005a; McMurray et al, 2008a; 2008b; Goodwin et al, 1992). We will review PCE-induced effects compared to those caused by being reared by a cocaine-exposed mother throughout developmental stages below.…”

Early postpartum pup preference is altered by gestational cocaine treatment: Associations with infant cues and oxytocin expression in the MPOA

“…Additionally, dam preference-like behavior and relationship with oxytocin (OT) expression in the medial preoptic area (MPOA) was explored, as OT has been shown to play an essential role in onset and maintenance of early maternal behavior in both human [25;26] and rodent models [27–29]. Additionally, OT dynamics has been shown to be altered in rat dams gestationally-exposed to cocaine [30–32], including decreased expression in the MPOA [33;34], a region consistently shown to be critical for maternal behavior [35–39]. However, the mechanisms underlying these relationships are still unclear with studies suggesting cocaine can directly alter OT dynamics [33;40;41] and recent studies suggesting maternal-infant interactions may regulate OT dynamics across the postpartum period [3;42–44].…”

Prenatal cocaine exposure: The role of cumulative environmental risk and maternal harshness in the development of child internalizing behavior problems in kindergarten

“…Maternal cocaine use has the potential to alter parenting behavior. Both animal and human studies indicate that mothers with CE had lower plasma oxytocin (sometimes called the “bonding hormone”) compared to non-substance using mothers (Johns, Lubin, Walker, Meter, & Mason, 1997; Light et al, 2004; McMurray, Cox, et al, 2008). This has been demonstrated to be one mechanism for cocaine effects on maternal caregiving or parenting behavior (Light et al, 2004; McMurray, Joyner, et al, 2008).…”