[Characteristics of GABA-activated chlorine channels in hippocampal slices]

A new preparation for patch clamp study of ion channels is reported. Transverse hippocampal slices were incubated in normal physiological solution for 8 h. When necessary they were transferred into the experimental chamber and torn immediately on the level of pyramidal layer. The neurons, visible on the torn surface, were capable of forming tight glass-membrane contacts. Preliminary measurements of GABA induced chlorine currents were performed by patch-lamp technique. There were at least two types of patches with different properties, activated by low and high GABA concentrations. The influence of diazepam on GABA sensitivity was also examined. The conclusion was made that diazepam enhanced the channel activity without affecting channel properties.