Environmental regulation of the development of mesolimbic dopamine systems: a neurobiological mechanism for vulnerability to drug abuse?
Repeated periods of maternal separation in the early life of rats decreased dopamine transporter expression and significantly increased dopamine responses to stress, and behavioral responses to either stress or cocaine. As adults, maternal separation animals showed increased sensitivity to the effects of cocaine on locomotor activity and greater sensitivity to stress-induced sensitization to the effects of amphetamine on locomotor activity. These findings raise the possibility that in addition to effects on stress reactivity, early life events might dispose individuals to illness in later life through effects on very specific neurotransmitter systems.
Meaney
Michael J
MJ
McGill Centre for the Study of Behavior, Genes and Environment, Douglas Hospital Research Centre, McGill University, 6875 Boul LaSalle, H4H 1R3, Montreal, Que., Canada. michael.meaney@mcgill.ca
Brake
Wayne
W
Gratton
Alain
A
D000818:Animals; D004298:Dopamine / Q000502:physiology*; D004777:Environment; D006801:Humans; D008032:Limbic System / Q000254:growth & development* / Q000502:physiology; D008426:Maternal Deprivation; D019966:Substance-Related Disorders / Q000209:etiology / Q000503:physiopathology*
D004298:Dopamine