Presynaptic D2 dopaminergic receptors mediate inhibition of excitatory synaptic transmission in rat neostriatum

Brain Res. 1995 Sep 4;690(2):264-8. doi: 10.1016/0006-8993(95)00734-8.


The effect of dopamine (DA) on excitatory synaptic transmission was studied in rat neostriatal neurons using intracellular- and whole-cell voltage clamp-recording methods. Depolarizing excitatory postsynaptic potentials (EPSPs) were evoked by cortical stimulation. Superfusion of DA (0.01-10 microM) reversibly decreases EPSP in a concentration-dependent manner and with a estimated IC50 of 0.3 microM. In addition, the inhibitory effect induced by DA at a low concentration (0.1 microM) was antagonized by sulpiride (1-10 nM), a selective D2 dopaminergic receptor antagonist. However, D1 dopaminergic receptor antagonist SKF-83566 (1-5 microM) did not affect the blocking effect by DA 0.1 microM. Based on these findings, we conclude that DA at a low concentration (< or = 0.1 microM) reduced the excitatory response of neostriatal neurons following cortical stimulation via the activation of D2, but not D1 dopaminergic receptors, located on the terminals of corticostriatal neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / analogs & derivatives
  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / pharmacology
  • Animals
  • Cerebral Cortex / physiology
  • Dopamine / pharmacology*
  • Dopamine Antagonists / pharmacology
  • Electric Stimulation
  • Evoked Potentials / drug effects
  • In Vitro Techniques
  • Neostriatum / cytology
  • Neostriatum / drug effects*
  • Neurons / drug effects*
  • Patch-Clamp Techniques
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Dopamine D2 / drug effects*
  • Receptors, Presynaptic / drug effects*
  • Sulpiride / pharmacology
  • Synaptic Transmission / drug effects*


  • Dopamine Antagonists
  • Receptors, Dopamine D2
  • Receptors, Presynaptic
  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine
  • Sulpiride
  • 1H-3-benzazepin-7-ol, 8-bromo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-
  • Dopamine