Modulation of K(+)-channels in p-neurones of the leech CNS by phosphorylation.

Two types of potassium channels of identified (p-) neurones of the leech (Hirudo medicinalis) were investigated by using the patch-clamp technique. The open-state probability of these channels in cell-attached patches can be reduced by addition of 5-hydroxytryptamine to the bath solution. After excising the patches the application of alkaline phosphatase to the cytosolic face of the patch increases the open probability. The 5-HT1A-receptor agonist buspirone mimics the effect of 5-HT. Our experiments show that the effect of 5-HT might be due to a channel phosphorylation via a 5-HT1A-receptor subtype.