TY - JOUR
T1 - Regulations of methamphetamine reward by extracellular signal-regulated kinase 1/2/ets-like gene-1 signaling pathway via the activation of dopamine receptors
AU - Mizoguchi, Hiroyuki
AU - Yamada, Kiyofumi
AU - Mizuno, Makoto
AU - Mizuno, Tomoko
AU - Nitta, Atsumi
AU - Noda, Yukihiro
AU - Nabeshima, Toshitaka
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/5
Y1 - 2004/5
N2 - Little is known about molecular mechanisms for long-lasting neuroadaptation related to the rewarding effects of methamphetamine (MAP). In the present study, we examined the intracellular signaling that is associated with the expression of conditioned place preference (CPP) induced by MAP in rats. Rats were given MAP or saline (control group) for conditioning to the CPP test. MAP-treated and control animals were killed immediately after the CPP test [CPP+]. Some of the MAP-treated rats were killed without the CPP test [CPP-]. Hyperphosphorylation of mitogen-activated protein kinase (MAPK) ERK1/2, but not p38 and c-Jun N-terminal kinase/stress-activated protein kinase, was found in the nucleus accumbens (NAc) and striatum but not in other brain areas of MAP-treated CPP+ animals. No such phosphorylation was seen in control and MAP-treated CPP- animals. Moreover, the transcription factor ets-like gene-1 (Elk-1), but not cAMP response element-binding protein, also showed a similar hyperphosphorylation in the same regions of MAP-treated CPP+. Tyrosine kinase receptors, including tyrosine kinase B, were not activated in any brain regions examined in all groups. Both the dopamine D1 receptor antagonist R-(+)-7-chloro-8-hydroxy-3- methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH23390) and the D2 receptor antagonist raclopride inhibited the expression of CPP as well as the activation of ERK1/2 in MAP-treated CPP+ animals, when they were injected before the CPP test. The microinjection of 2′-amino-3′- methoxyflavone (PD98059), a selective MAPK kinase inhibitor, into the NAc before the test, abolished the MAP-induced ERK1/2 activation and decreased the expression of MAP-induced CPP. These results suggest the importance of the ERK1/2 signaling pathway through activation of dopamine D1 and D2 receptors in the expression of CPP induced by MAP.
AB - Little is known about molecular mechanisms for long-lasting neuroadaptation related to the rewarding effects of methamphetamine (MAP). In the present study, we examined the intracellular signaling that is associated with the expression of conditioned place preference (CPP) induced by MAP in rats. Rats were given MAP or saline (control group) for conditioning to the CPP test. MAP-treated and control animals were killed immediately after the CPP test [CPP+]. Some of the MAP-treated rats were killed without the CPP test [CPP-]. Hyperphosphorylation of mitogen-activated protein kinase (MAPK) ERK1/2, but not p38 and c-Jun N-terminal kinase/stress-activated protein kinase, was found in the nucleus accumbens (NAc) and striatum but not in other brain areas of MAP-treated CPP+ animals. No such phosphorylation was seen in control and MAP-treated CPP- animals. Moreover, the transcription factor ets-like gene-1 (Elk-1), but not cAMP response element-binding protein, also showed a similar hyperphosphorylation in the same regions of MAP-treated CPP+. Tyrosine kinase receptors, including tyrosine kinase B, were not activated in any brain regions examined in all groups. Both the dopamine D1 receptor antagonist R-(+)-7-chloro-8-hydroxy-3- methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH23390) and the D2 receptor antagonist raclopride inhibited the expression of CPP as well as the activation of ERK1/2 in MAP-treated CPP+ animals, when they were injected before the CPP test. The microinjection of 2′-amino-3′- methoxyflavone (PD98059), a selective MAPK kinase inhibitor, into the NAc before the test, abolished the MAP-induced ERK1/2 activation and decreased the expression of MAP-induced CPP. These results suggest the importance of the ERK1/2 signaling pathway through activation of dopamine D1 and D2 receptors in the expression of CPP induced by MAP.
UR - http://www.scopus.com/inward/record.url?scp=2142655891&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2142655891&partnerID=8YFLogxK
U2 - 10.1124/mol.65.5.1293
DO - 10.1124/mol.65.5.1293
M3 - Article
C2 - 15102958
AN - SCOPUS:2142655891
VL - 65
SP - 1293
EP - 1301
JO - Molecular Pharmacology
JF - Molecular Pharmacology
SN - 0026-895X
IS - 5
ER -