Different effects of GABAergic receptors located in the ventral tegmental area on the expression of morphine-induced conditioned place preference in rat.
In the present study, an unbiased conditioned place preference paradigm was used to study the effects of intra-ventral tegmental area injections of Gama-amino-butyric acid (GABA)-A and B (GABA(A) and GABA(B)) receptor agonists and antagonists on the expression of morphine-induced conditioned place preference (CPP) in rats. Subcutaneous (s.c.) injections of morphine sulfate (5 mg/kg) induced CPP. Intra-ventral tegmental area administration of the GABA(A) receptor agonist, muscimol (6 microg/rat) reduced the expression of morphine-induced CPP. Muscimol (25 microg/rat) increased the expression of CPP induced by morphine. A reduction of the expression of morphine-induced CPP was observed on intra-ventral tegmental area injection of GABA(A) receptor antagonist bicuculline (25 microg/rat). Bicuculline (10 microg/rat) increased the expression of CPP induced by morphine. Baclofen (12 microg/rat) increased where as (19 and 25 microg/rat) reduced the expression of morphine-induced CPP. Injection of CGP38345 (10, 19, 25 and 50 microg/rat) into the ventral tegmental area significantly reduced the expression of CPP induced by morphine. It is concluded that GABA(A) and GABA(B) receptor subtypes within the ventral tegmental area may have different effects on the expression of morphine-induced CPP.
Sahraei
Hedayat
H
Department of Physiology and Biophysics, School of Medicine and Behavioral Sciences Research Center, Baqiyatallah (a.s.) University of Medical Sciences, Araj st., Niavaran, Tehran, Iran. h.Sahraei@bmsu.ac.ir
Amiri
Yar-Ali
YA
Haeri-Rohani
Ali
A
Sepehri
Houri
H
Salimi
Seyed Hossein
SH
Pourmotabbed
Ali
A
Ghoshooni
Hassan
H
Zahirodin
Ali
A
Zardooz
Homeira
H
D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D001640:Bicuculline / Q000494:pharmacology; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D018755:GABA Agonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009118:Muscimol / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018079:Receptors, GABA / Q000502:physiology*; D011963:Receptors, GABA-A / Q000502:physiology; D018080:Receptors, GABA-B / Q000502:physiology; D017557:Ventral Tegmental Area / Q000187:drug effects* / Q000502:physiology
D000701:Analgesics, Opioid; D018755:GABA Agonists; D018756:GABA Antagonists; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D009943:Organophosphorus Compounds; D018079:Receptors, GABA; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D009118:Muscimol; D009020:Morphine; C066430:CGP 35348; D001418:Baclofen; D001640:Bicuculline