Social dominance in monkeys: dopamine D2 receptors and cocaine self-administration.
Disruption of the dopaminergic system has been implicated in the etiology of many pathological conditions, including drug addiction. Here we used positron emission tomography (PET) imaging to study brain dopaminergic function in individually housed and in socially housed cynomolgus macaques (n = 20). Whereas the monkeys did not differ during individual housing, social housing increased the amount or availability of dopamine D2 receptors in dominant monkeys and produced no change in subordinate monkeys. These neurobiological changes had an important behavioral influence as demonstrated by the finding that cocaine functioned as a reinforcer in subordinate but not dominant monkeys. These data demonstrate that alterations in an organism's environment can produce profound biological changes that have important behavioral associations, including vulnerability to cocaine addiction.
Morgan
Drake
D
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA.
Grant
Kathleen A
KA
Gage
H Donald
HD
Mach
Robert H
RH
Kaplan
Jay R
JR
Prioleau
Osric
O
Nader
Susan H
SH
Buchheimer
Nancy
N
Ehrenkaufer
Richard L
RL
Nader
Michael A
MA
D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003042:Cocaine / Q000008:administration & dosage*; D006799:Housing, Animal; D008252:Macaca fascicularis; D008297:Male; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012646:Self Administration; D012930:Social Dominance; D012931:Social Environment; D012934:Social Isolation; D014055:Tomography, Emission-Computed
D017448:Receptors, Dopamine D2; D003042:Cocaine