Forskolin enhancement of opioid currents in rat locus coeruleus neurons

Abstract

1. Opioids are known to hyperpolarize all neurons in the nucleus locus coeruleus (LC) and to inhibit adenylyl cyclase. Recent work has shown that activation of adenylyl cyclase with forskolin in creased the amplitude of the opioid hyperpolarization in LC cells. The aim of the present study was to determine the mechanism of this augmented hyperpolarization. 2. Agonist- induced currents were studied in LC cells in brain slices using both intracellular and whole cell recordings. Forskolin increased the amplitude of μ-opioid- and α2-adrenoceptor-mediated currents by ~30% of control measured at -60 mV. This effect of forskolin was dependent on the concentration having a threshold of ~1 μM and a p..