Prenatal exposure to cocaine increases the rewarding potency of cocaine and selective dopaminergic agonists in adult mice.
BACKGROUND
Substance abuse during pregnancy results in persistent affective and behavioral deficits in drug-exposed children, and increased rates of substance abuse have been observed in young adults prenatally exposed to drugs of abuse. Animal models of prenatal cocaine exposure have yielded differing results depending on the behavioral method used to assess drug potency.


METHODS
The effects of cocaine, the dopamine D1 agonists SKF-81297 and SKF-82958, and the D2 agonist quinpirole on intracranial self-stimulation were measured in adult Swiss-Webster mice exposed to cocaine in utero (40 mg/kg/day) and vehicle controls with the curve-shift method of brain stimulation-reward (BSR) threshold determination.


RESULTS
The reward-potentiating effects of cocaine (0.3-30 mg/kg IP) and SKF-82958 but not SKF-81297 on BSR were increased in adult male but not female mice after prenatal cocaine exposure. Quinpirole exerted biphasic effects on BSR, both elevating (0.1-0.3 mg/kg IP) and lowering (1.0-10 mg/kg IP) reward thresholds. Both effects of quinpirole were also enhanced in adult male mice after prenatal cocaine exposure.


CONCLUSIONS
Prenatal cocaine exposure results in increased reward-potentiating potency of cocaine on BSR in adult mice in a sexually-dimorphic manner. This augmented rewarding effect of cocaine is also associated with increased sensitivity to both D1- and D2-selective agonists.
Malanga
C J
CJ
Laboratory of Molecular and Developmental Neuroscience, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA. malangacj@neurology.unc.edu
Riday
Thorfinn T
TT
Carlezon
William A
WA
Kosofsky
Barry E
BE
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000503:physiopathology / Q000528:radiation effects; D003042:Cocaine / Q000008:administration & dosage / Q000009:adverse effects; D003216:Conditioning, Operant / Q000187:drug effects; D018491:Dopamine Agonists / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D008297:Male; D051379:Mice; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012201:Reward; D012653:Self Stimulation; D012737:Sex Factors
D018491:Dopamine Agonists; D003042:Cocaine