The cochlear nuclei are the first brain centers for auditory processing, where synaptic inhibition shapes neural output. Using patch-clamp recordings in avian and mammalian brainstem slices, this study examined inhibitory mechanisms. In chicks, inhibitory currents varied across nuclei specialized for timing or intensity processing, with glycine and GABA receptors contributing differentially. In mammals, glycinergic vertical cells exhibited fast-spiking properties but weak individual influence on principal neurons, requiring coordinated activity. Cartwheel cells, by contrast, fired spontaneously, and noradrenaline enhanced stimulus-evoked inhibition by suppressing spontaneous firing. These findings reveal diverse inhibitory strategies for auditory signal processing.
