Influence of GABA on Potassium Channels in Hippocampal Neurons

Abstract

A wide range of neurotransmitters, such as gamma-aminobutyric acid (GABA), serotonin (5-hydroxytryptamine, 5HT), acetylcholine, noradrenaline, dopamine, and adenosine, have been found to activate potassium channels in central neurons. It is possible that many of these transmitters activate the same potassium channels (Nicoll et al., 1990). An increase in potassium conductance would make cells less excitable and would clearly influence neuronal behavior. In this chapter, we will focus our attention on the characteristics of potassium channels activated and modulated by GABA in the mammalian hippocampus. Emphasis will be placed on “subconductance” states of these channels and their relationship to normal channel behavior. It may turn out that the other transmitters activate and modulate channels in a similar way.