Mice lacking dopamine D4 receptors are supersensitive to ethanol, cocaine, and methamphetamine.
The human dopamine D4 receptor (D4R) has received considerable attention because of its high affinity for the atypical antipsychotic clozapine and the unusually polymorphic nature of its gene. To clarify the in vivo role of the D4R, we produced and analyzed mutant mice (D4R-/-) lacking this protein. Although less active in open field tests, D4R-/- mice outperformed wild-type mice on the rotarod and displayed locomotor supersensitivity to ethanol, cocaine, and methamphetamine. Biochemical analyses revealed that dopamine synthesis and its conversion to DOPAC were elevated in the dorsal striatum from D4R-/- mice. Based on these findings, we propose that the D4R modulates normal, coordinated and drug-stimulated motor behaviors as well as the activity of nigrostriatal dopamine neurons.
Rubinstein
M
M
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, CONICET, and Depto. Química Biologica, FCEyN, Universidad de Buenos Aires, Argentina.
Phillips
T J
TJ
Bunzow
J R
JR
Falzone
T L
TL
Dziewczapolski
G
G
Zhang
G
G
Fang
Y
Y
Larson
J L
JL
McDougall
J A
JA
Chester
J A
JA
Saez
C
C
Pugsley
T A
TA
Gershanik
O
O
Low
M J
MJ
Grandy
D K
DK
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003024:Clozapine / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000033:anatomy & histology / Q000737:chemistry / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D005838:Genotype; D006801:Humans; D007980:Levodopa / Q000032:analysis / Q000493:pharmacokinetics; D008124:Locomotion / Q000187:drug effects; D008425:Maternal Behavior / Q000187:drug effects; D008694:Methamphetamine / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009043:Motor Activity / Q000187:drug effects; D016297:Mutagenesis, Site-Directed / Q000502:physiology; D009294:Narcotics / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000737:chemistry / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000172:deficiency / Q000235:genetics*; D050638:Receptors, Dopamine D4; D012680:Sensitivity and Specificity; D013378:Substantia Nigra / Q000033:anatomy & histology / Q000737:chemistry / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D014150:Antipsychotic Agents; D002492:Central Nervous System Depressants; C493599:DRD4 protein, human; D015259:Dopamine Agents; C493600:Drd4 protein, mouse; D009294:Narcotics; D017448:Receptors, Dopamine D2; D015102:3,4-Dihydroxyphenylacetic Acid; D050638:Receptors, Dopamine D4; D000431:Ethanol; D008694:Methamphetamine; D007980:Levodopa; D003042:Cocaine; D003024:Clozapine; D004298:Dopamine