QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (38) Citing Articles via Google Scholar Google Scholar Articles by Dong, Y. Articles by White, F. J. Search for Related Content PubMed PubMed Citation Articles by Dong, Y. Articles by White, F. J.

 Previous Article  |  Next Article 

The Journal of Neuroscience, April 1, 2003, 23(7):2686

Dopamine D1-Class Receptors Selectively Modulate a Slowly Inactivating Potassium Current in Rat Medial Prefrontal Cortex Pyramidal Neurons

Yan Dong¹ and Francis J. White²

Departments of ¹ Neuroscience and ² Cellular and Molecular Pharmacology, Finch University of Health Sciences/The Chicago Medical School, North Chicago, Illinois 60064

The dopamine (DA) innervation of medial prefrontal cortex (mPFC) regulates cognitive activity in a complex manner. Alterations of DA function, particularly via the DA D1 receptor class (D1R), are implicated in both schizophrenia and drug addiction, yet the precise roles of DA in modulating mPFC excitability remain unclear. We focused on DA modulation of voltage-gated K⁺ current (VGKC) in acutely dissociated rat mPFC pyramidal neurons. We defined three components of the whole-cell VGKC according to biophysical and pharmacological properties. The A-type current (I_A), with rapid activation and inactivation kinetics, was completely inactivated by prolonged holding of the membrane potential at 40 mV and was sensitive to the K⁺ channel blocker 4-aminopyridine (4-AP) but not tetraethylammonium (TEA) or dendrotoxin (DTX). The slowly inactivating K⁺ current (I_D), with rapid activation but relatively slow inactivation, was the major contributor to VGKC and was completely inactivated at 40 mV and sensitive to TEA and DTX but less so to 4-AP. The very slowly inactivating K⁺ current (I_K) was elicited by command steps to more depolarized potentials from a prolonged holding potential of 40 mV and was sensitive to all three blockers. Stimulation of DA D2 receptors failed to alter any component of whole-cell VGKC. Stimulation of DA D1Rs selectively suppressed I_D, an effect mimicked by the adenylyl cyclase activator forskolin, the active cAMP analog Sp-cAMP, and the protein phosphatase inhibitor okadaic acid. Inhibition of protein kinase A (PKA) with either PKI or Rp-cAMP abolished D1R modulation. Thus, the DA D1R/cAMP/PKA signaling pathway mediates modulation of I_D by DA in rat mPFC pyramidal neurons.

Key words: dopamine; prefrontal cortex; potassium current; dopamine D1 receptors; drug addiction; schizophrenia

---

Copyright © 2003 Society for Neuroscience  0270-6474/03/2372686-10$05.00/0

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help