GABA ALTERS THE DISCHARGE PATTERN OF CHOPPER NEURONS IN THE RAT VENTRAL COCHLEAR NUCLEUS

The effect of microiontophoretically applied gamma-aminobutyric acid ( GABA) on chopper neurons in the ventral cochlear nucleus of the rat is described. The predominantly inhibitory effect of GABA resulted in a change of the regular discharge pattern. The interspike interval incre ased and the pattern became less regular as indicated by an increase o f its coefficient of variation. These results suggest that the release of GABA may be responsible for the transient chopper behavior of some neurons which loose their regular discharge pattern within 20 ms afte r onset of the response to pure-tone stimulation.