Actions of D-Ala2-D-Leu5-enkephalin and dynorphin A (1-17) on neocortical neurons in vitro.

ABSTRACT

Intracellular recordings were made from neocortical neurons in vitro. Application of D-Ala2-D-Leu5-enkephalin (DADL) by different methods produced a decrease in EPSP amplitude and in the amplitude of L-glutamate-induced depolarizations without changes in membrane potential or membrane input resistance. The DADL effects were blocked by naloxone and persisted when synaptic transmission was depressed, suggesting DADL acts on postsynaptically located opiate receptors. With dynorphin A (1-17), depolarizations, hyperpolarizations, decreases and increases in EPSP were observed, but never an anti-glutamate effect.