| Citation | Alan North has made outstanding and novel contributions to our knowledge of neurotransmitter action, and of membrane ion channels and their regulation. For example, in early work on enteric neurons he first revealed the ionic basis for the inhibitory actions of opioids and the excitatory actions of certain other peptides: these were due to the opening and closing respectively of different subsets of potassium channels. He then showed that the same mechanisms underlie effects of these and many other transmitters throughout the mammalian nervous system, thereby establishing the important principle of convergent neurotransmitter action. Further studies on the dual (fast/slow) transmitter action of 5-hydroxytryptamine demonstrated the converse principle of divergence. His most recent work has involved the application of molecular biological techniques such as site-directed mutagenesis to probe sites of ion channel regulation at the single molecule level. While directed at the single cell and molecule, his elegant work has also had a major impact on our understanding of integrative neural function and of drug action on the nervous system. |