Dose-related effects of chronic gestational cocaine treatment on maternal aggression in rats on postpartum days 2, 3, and 5.
Gravid Sprague-Dawley rats received subcutaneous injections of saline, 3.5, 7.5 or 15 mg/kg of cocaine, twice daily, throughout gestation. On postpartum days 2, 3, and 5, dams and their litters (surrogate or natural) were videotaped for 10 minutes in the presence of a male rat for assessment of aggression towards the intruder. Oxytocin levels in discrete brain areas were assayed on postpartum day 5. The 30 mg/kg dose group had a significantly greater increase in the frequency of threats from postpartum day2 through postpartum day 5 than the 7.5 mg/kg cocaine and the non-yoke-fed saline control groups. Dams with natural litters exhibited a significantly greater frequency of receptive behavior compared to dams with surrogate litters. There were no significant differences in oxytocin levels between the 30 mg/kg cocaine-treated group and the other treatment or control groups on postpartum day 5. There are very few statistically significant cocaine-induced increases in maternal aggressive behavior and no dose-dependent decreases in amygdaloid OT levels in the early postpartum period.
Lubin
D A
DA
Department of Psychology, University of North Carolina at Chapel Hill, 27599, USA. dlubin@css.unc.edu
Meter
K E
KE
Walker
C H
CH
Johns
J M
JM
D000374:Aggression / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003042:Cocaine / Q000008:administration & dosage*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007279:Injections, Subcutaneous; D008297:Male; D008425:Maternal Behavior / Q000187:drug effects*; D010121:Oxytocin / Q000378:metabolism; D049590:Postpartum Period / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley
D018765:Dopamine Uptake Inhibitors; D010121:Oxytocin; D003042:Cocaine