Use of the whole-cell patch-clamp method in studies on the role of cAMP in regulating the spontaneous firing of locus coeruleus neurons.

The whole-cell patch-clamp technique represents a major advance over conventional intracellular recordings in the study of the modulation of ion channels by intracellular messengers. This report illustrates how application of the whole-cell technique to noradrenergic neurons of the rat locus coeruleus in brain slices has led to the finding that cAMP via its phosphorylation pathway modulates tonic pacemaking in these neurons. In the studies to be described, the particular advantage of the whole-cell technique was that it allowed introduction of macromolecules related to the cAMP pathway (e.g., protein kinase inhibitor and protein kinase A) directly into cells. Furthermore, these studies were carried out in situ, in thick brain slices allowing a direct comparison with a large body of existing extracellular and intracellular data obtained under similar conditions.