Dopamine Modulates Inwardly Rectifying Potassium Currents in Medial Prefrontal Cortex Pyramidal Neurons

NASIF, FERNANDO

JOURNAL OF NEUROSCIENCE

SOC NEUROSCIENCE

Año: 2004 vol. 24 p. 3077 - 3077

0270-6474

opamine (DA) modulation of excitability in medial prefrontal cortex (mPFC) pyramidal neurons has attracted considerable attention because of the involvement of mPFC DA in several neuronal disorders. Here, we focused on DA modulation of inwardly rectifying K+ current (IRKC) in pyramidal neurons acutely dissociated from rat mPFC. A Cs+-sensitive whole-cell IRKC was elicited by hyperpolarizing voltage steps from a holding potential of -50 mV. DA (20μM) reduced IRKC amplitude, as did selective stimulation of DA D1 or D2 class receptors (D 1Rs and D2Rs). D1Rs activate, whereas D 2Rs inhibit, the adenylyl cyclase-cAMP-protein kinase A (PKA) signaling pathway. Suppression of IRKC by D2R stimulation was attributable to decreased PKA activity because similar inhibition was observed with PKA inhibitors, whereas enhancing PKA activity increased IRKC. This suggests that the DA D1R suppression of IRKC occurred through a PKA phosphorylation-independent process. Using outside-out patches of mPF