Role for GABA agonists in the nucleus accumbens in regulating morphine self-administration.
In the present study, functional roles of GABA receptors in the nucleus accumbens on morphine self-administration behavior were investigated. Male Sprague-Dawley rats were trained to press lever for morphine (0.1 mg/kg per infusion) during daily 1-h self-administration session. After establishing stable baseline responses, rats were given microinjections of the GABA(A) receptor agonist muscimol (0, 250 and 500 ng/microl, bilateral) or the GABA(B) receptor agonist baclofen (0, 100 and 250 ng/microl, bilateral) into the nucleus accumbens immediately before the morphine self-administration. Microinjection of muscimol (250 and 500 ng/microl) into the nucleus accumbens, but not baclofen, decreased morphine self-administration responses. These results suggest that activation of GABA(A) receptors, but not GABA(B) receptors, in the nucleus accumbens plays a critical role in modulating the reinforcing effects of morphine.
Yoon
Seong Shoon
SS
College of Oriental Medicine, Daegu Haany University, Daegu 706-828, South Korea.
Kim
Jung-Ae
JA
Lee
Bong Hyo
BH
Choi
Kwang-Ho
KH
Shim
Insop
I
Choi
Seong Hun
SH
Hwang
Meeyul
M
Yang
Chae Ha
CH
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D018755:GABA Agonists / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009118:Muscimol / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology*; D018080:Receptors, GABA-B / Q000502:physiology*; D012054:Reinforcement, Psychology; D012646:Self Administration
D018755:GABA Agonists; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D009118:Muscimol; D009020:Morphine; D001418:Baclofen