Amygdala dopamine levels are markedly elevated after self- but not passive-administration of cocaine.
The influence of cocaine on rat brain monoaminergic neurotransmitters (dopamine, serotonin, noradrenaline) and their metabolites, and on binding of [3H]WIN 35,428 and [3H]GBR 12,935 to the dopamine transporter was measured after 4 weeks of cocaine exposure. Cocaine (mean daily dose 9.25 +/- 0.48 mg/kg) was self-administered (responders) or passively received (yoked) during sessions which lasted for 1 h per day. As compared with the controls, mean dopamine and serotonin levels were significantly elevated (+ 107% and + 47%, respectively) in amygdala of responders, but not of yoked rats, sacrificed 1 h after the last cocaine session. Dopamine and metabolite levels were normal in all other brain areas examined, including striatum, nucleus accumbens and medial prefrontal cortex, at both 1 h and 4 weeks withdrawal from cocaine. [3H]WIN 35,428 and [3H]GBR 12,935 binding were unaltered after cocaine exposure. These data provide additional support for the involvement of the amygdala in the acquisition of drug seeking behavior associated with cocaine self-administration.
Wilson
J M
JM
Human Neurochemical Pathology Laboratory, Clarke Institute of Psychiatry, Toronto, Ont. Canada.
Nobrega
J N
JN
Corrigall
W A
WA
Coen
K M
KM
Shannak
K
K
Kish
S J
SJ
D000679:Amygdala / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003042:Cocaine / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000032:analysis; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D004334:Drug Administration Schedule; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009638:Norepinephrine / Q000378:metabolism; D010879:Piperazines / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012653:Self Stimulation; D012701:Serotonin / Q000378:metabolism
D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D010879:Piperazines; D012701:Serotonin; C021279:(1R-(exo,exo))-3-(4-fluorophenyl)-8-methyl-8- azabicyclo(3.2.1)octane-2-carboxylic acid, methyl ester; C044630:1-(2 (diphenylmethoxy)ethyl)-4-(3-phenylpropyl)piperazine; D003042:Cocaine; D004298:Dopamine; D009638:Norepinephrine