PMID- 18086480
OWN - NLM
STAT- MEDLINE
DCOM- 20080612
LR  - 20220408
IS  - 0028-3908 (Print)
IS  - 0028-3908 (Linking)
VI  - 54
IP  - 3
DP  - 2008 Mar
TI  - Inhibition of morphine-induced amnesia in morphine-sensitized mice: involvement 
      of dorsal hippocampal GABAergic receptors.
PG  - 569-76
AB  - In the present study, the effects of bilateral injections of the GABAergic 
      receptor agents into the dorsal hippocampal CA1 regions (intra-CA1) on 
      morphine-induced amnesia were examined in morphine sensitized-mice. Pre-training 
      subcutaneous (s.c.) administration of morphine (5 mg/kg) suppressed the learning 
      of a one-trial passive avoidance task. Amnesia induced by pre-training morphine 
      was significantly reversed in mice which had previously received once daily 
      injections of morphine (20 and 30 mg/kg, s.c.) for 3 days, which may be due to 
      behavioral sensitization. Intra-CA1 injections of GABAA receptor agonist, 
      muscimol (0.125, 0.25, 0.5 and 1 microg/mouse) or the GABAB receptor agonist, 
      baclofen (1, 1.5 and 2 microg/mouse) prior to injection of morphine (20 mg/kg per 
      dayx3 days) decreased the reversion of morphine-induced amnesia in morphine 
      sensitized-mice. Daily intra-CA1 injections of muscimol or baclofen plus saline 
      for 3 days did not alter memory formation. Furthermore, during development of 
      sensitization, the combination of GABAA receptor antagonist, bicuculline (0.25, 
      0.5, 1 and 2 microg/mouse) with an ineffective dose of morphine (5 mg/kg, s.c.) 
      reversed the amnesia induced by pre-training morphine. However, the same 
      treatment with GABAB receptor antagonist, CGP35348 (2.5-40 microg/mouse) had no 
      effect on the morphine response. On the other hand, daily intra-CA1 injections of 
      bicuculline or CGP35348 alone for 3 days did not alter the amnesia induced by 
      pre-training injection of morphine. The results suggest that morphine 
      sensitization reverses the impairment of memory induced by morphine and that 
      GABAergic receptors of the dorsal hippocampus may play an important role in this 
      effect.
FAU - Zarrindast, Mohammad-Reza
AU  - Zarrindast MR
AD  - Department of Pharmacology, School of Medicine, and Iranian National Center for 
      Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran. 
      zarinmr@ams.ac.ir
FAU - Hoghooghi, Vahid
AU  - Hoghooghi V
FAU - Rezayof, Ameneh
AU  - Rezayof A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20071117
PL  - England
TA  - Neuropharmacology
JT  - Neuropharmacology
JID - 0236217
RN  - 0 (GABA Agents)
RN  - 0 (Receptors, GABA)
RN  - 76I7G6D29C (Morphine)
SB  - IM
MH  - *Amnesia/chemically induced/pathology/psychology
MH  - Animals
MH  - Avoidance Learning/drug effects
MH  - Behavior, Animal
MH  - Drug Administration Schedule
MH  - Drug Interactions
MH  - GABA Agents/pharmacology
MH  - Hippocampus/drug effects/*metabolism
MH  - *Inhibition, Psychological
MH  - Male
MH  - Mice
MH  - *Morphine
MH  - Reaction Time/drug effects
MH  - Receptors, GABA/*physiology
EDAT- 2007/12/19 09:00
MHDA- 2008/06/13 09:00
CRDT- 2007/12/19 09:00
PHST- 2007/07/24 00:00 [received]
PHST- 2007/11/03 00:00 [revised]
PHST- 2007/11/08 00:00 [accepted]
PHST- 2007/12/19 09:00 [pubmed]
PHST- 2008/06/13 09:00 [medline]
PHST- 2007/12/19 09:00 [entrez]
AID - S0028-3908(07)00364-4 [pii]
AID - 10.1016/j.neuropharm.2007.11.004 [doi]
PST - ppublish
SO  - Neuropharmacology. 2008 Mar;54(3):569-76. doi: 10.1016/j.neuropharm.2007.11.004. 
      Epub 2007 Nov 17.