Activation of μ- and δ-Opioid Receptors Causes Presynaptic Inhibition of Glutamatergic Excitation in Neocortical Neurons

Abstract

Activation of mu- and delta-opioid receptors depresses glutamatergic excitatory transmission evoked in neocortical neurons by presynaptic inhibition. A weak activation of a postsynaptic potassium conductance becomes evident only at high agonist concentrations. There is no evidence for a postsynaptic interaction between glutamate and opioid receptors.