Centrifugal inhibitory processes affecting neurones in the cat cochlear nucleus.

1. Stimulation of the lateral part of the olivary S-segment in the cat inhibited neurones in the ipsilateral cochlear nucleus. A smaller number of neurones located in the ventral division of the cochlear nucleus were excited.2. It is suggested that inhibition in the ipsilateral cochlear nucleus may be mediated directly by fibres making synaptic connexions on the cochlear nucleus neurones, or indirectly by inhibitory fibres acting at the cochlea.3. The direct inhibitory process at the cochlear nucleus is unaffected by strychnine, whereas the inhibitory process at the cochlea is abolished by strychnine.4. A cochlear nucleus neurone can be influenced simultaneously by excitatory and inhibitory processes.