Patch-clamp study on membrane properties and transmitter activated currents of rabbit area postrema neurons.

Using the patch-clamp technique in combination wit sliced tissue preparation the membrane properties of newborn rabbit area postrema neurons were investigated. The neurons responded upon depolarization with a fast Na+-current followed by an inactivating and non-inactivating K+-current. GABA-activated currents were investigated resulting in a large C1-(-)conductance, indicating the expression of GABAA-receptors. The expression of glutamate receptor mRNA was studied by in situ hybridization and electrophysiological measurements of these receptors by means of the patch-clamp technique. As a main result it was found that ionotropic glutamate receptors in the area postrema are composed of "flop" variants of the GluA-, GluB- and GluC-subunits.