Dopamine D1 receptors and group I metabotropic glutamate receptors contribute to the induction of long-term potentiation in the nucleus accumbens.
Long-term changes in the efficacy of glutamatergic synaptic transmission in the striatal complex are proposed to underlie motor learning and neuroadaptations leading to addiction. Dopamine and glutamate play key roles in the induction of long-term potentiation (LTP) and long-term depression (LTD) in the dorsal striatum, but their contribution to synaptic plasticity in the ventral striatum (nucleus accumbens, NAc) has been less extensively studied. We have examined the role of dopamine, glutamate and GABA in the induction of LTP in mouse brain slices containing the NAc. High-frequency stimulation of glutamatergic inputs elicited LTP of field excitatory postsynaptic potentials/population spikes (fEPSP/PSs) in the core region of the NAc. GABA did not seem to participate in LTP induction because LTP was not altered in the presence of either a GABA(A)- (bicuculline) or a GABA(B)- (CGP 55845) receptor antagonist. However, the dopamine D1 receptor antagonist SCH 23390, but not the dopamine D2 receptor antagonist sulpiride, impaired LTP. The dopamine reuptake blocker nomifensine also inhibited LTP induction. We found that group I metabotropic glutamate receptors (mGluRs) contribute to LTP induction because the mGluR1 antagonist LY 367385, or the mGluR5 antagonist MPEP, blocked LTP induction. Furthermore, the glutamate reuptake blocker DL-TBOA also impaired LTP. The present results demonstrate that dopamine and glutamate play critical roles in the mechanisms of induction of LTP in the NAc through the activation of dopamine D1 receptors and group I mGluRs. However, LTP is negatively regulated when endogenous levels of dopamine or glutamate are elevated.
Schotanus
Sietske M
SM
Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, The Karolinska Institute, Von Eulers väg 8, 171 77 Stockholm, Sweden.
Chergui
Karima
K
D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D001565:Benzoates / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D018756:GABA Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009714:Nucleus Accumbens / Q000502:physiology*; D010721:Phosphinic Acids / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D017447:Receptors, Dopamine D1 / Q000502:physiology*; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D001565:Benzoates; D018492:Dopamine Antagonists; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D010721:Phosphinic Acids; D011412:Propanolamines; D011725:Pyridines; D017447:Receptors, Dopamine D1; D018094:Receptors, Metabotropic Glutamate; C120673:benzyloxyaspartate; C104077:metabotropic glutamate receptor type 1; C079694:alpha-methyl-4-carboxyphenylglycine; C085075:CGP 55845A; D001224:Aspartic Acid; D013469:Sulpiride; C121465:6-methyl-2-(phenylethynyl)pyridine; D005998:Glycine; D001640:Bicuculline