PMID- 15767843 OWN - NLM STAT- MEDLINE DCOM- 20050715 LR - 20191210 IS - 0955-8810 (Print) IS - 0955-8810 (Linking) VI - 16 IP - 2 DP - 2005 Mar TI - Repeated administration of dopaminergic agents in the dorsal hippocampus and morphine-induced place preference. PG - 85-92 AB - The aim of the present experiments was to investigate whether repeated intra-hippocampal CA1 (intra-CA1) administration of dopaminergic agents can affect morphine-induced conditioned place preference (CPP). Effects of repeated intra-CA1 injections of dopamine (DA) receptor agonists and antagonists on morphine-induced CPP in rats were investigated using an unbiased 3-day schedule of place conditioning. Animals receiving once-daily subcutaneous (s.c.) injections of morphine (1-9 mg/kg) or saline (1.0 ml/kg, s.c.) showed a significant place preference in a dose-dependent manner: the maximum response was observed with 3 mg/kg morphine. Three days' intra-CA1 injections of apomorphine (0.25-1 microg/rat) followed by 5 days free of the drug, significantly decreased morphine CPP (1 and 3 mg/kg, s.c.). Moreover, pre-treatment with the highest dose of apomorphine (1 microg/rat) altered the effect of morphine to an aversive response. The morphine (1 and 3 mg/kg) CPP was also significantly decreased in animals that previously received three intra-CA1 injections of SKF 38393 (2-9 microg/rat), quinpirole (1-3 microg/rat) or sulpiride (1-3 microg/rat), and significantly increased in animals that had previously received three intra-CA1 injections of SCH 23390 (0.02 microg/rat). The 3-day pre-treatment with apomorphine, SKF 38393 or quinpirole reduced locomotor activity in the test session, while SCH 23390 and sulpiride did not have any influence on locomotor activity. It is concluded that repeated injections of DA receptor agents in the dorsal hippocampus, followed by 5 days free of the drugs, can affect morphine reward. FAU - Zarrindast, M-R AU - Zarrindast MR AD - Department of Pharmacology and Iranian National Center for Addiction Studies, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. zarinmr@ams.ac.ir FAU - Nasehi, M AU - Nasehi M FAU - Rostami, P AU - Rostami P FAU - Rezayof, A AU - Rezayof A FAU - Fazli-Tabaei, S AU - Fazli-Tabaei S LA - eng PT - Journal Article PL - England TA - Behav Pharmacol JT - Behavioural pharmacology JID - 9013016 RN - 0 (Dopamine Agonists) RN - 0 (Narcotics) RN - 20OP60125T (Quinpirole) RN - 67287-49-4 (2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine) RN - 76I7G6D29C (Morphine) RN - N21FAR7B4S (Apomorphine) SB - IM MH - 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/*pharmacology MH - Animals MH - Apomorphine/administration & dosage/*pharmacology MH - *Conditioning, Classical MH - Dopamine Agonists/administration & dosage/*pharmacology MH - Dose-Response Relationship, Drug MH - Hippocampus/*drug effects/*physiology MH - Injections, Subcutaneous MH - Male MH - Morphine/administration & dosage/*pharmacology MH - Narcotics/administration & dosage/*pharmacology MH - Quinpirole/*pharmacology MH - Rats MH - Rats, Wistar MH - Reinforcement, Psychology MH - Space Perception EDAT- 2005/03/16 09:00 MHDA- 2005/07/16 09:00 CRDT- 2005/03/16 09:00 PHST- 2005/03/16 09:00 [pubmed] PHST- 2005/07/16 09:00 [medline] PHST- 2005/03/16 09:00 [entrez] AID - 00008877-200503000-00003 [pii] AID - 10.1097/00008877-200503000-00003 [doi] PST - ppublish SO - Behav Pharmacol. 2005 Mar;16(2):85-92. doi: 10.1097/00008877-200503000-00003.