RESUMO
Synaptic inputs from one cochlear nucleus (CN) to the other can play an important role in modulating the activity of CN neurons. Using the isolated whole brain preparation of the guinea pig, we tested the effects of electrical stimulation of the contralateral auditory nerve (AN) on intracellularly recorded and stained neurons of the anteroventral cochlear nucleus. Stimulation of the contralateral AN evoked only inhibitory postsynaptic potentials (IPSPs) in 63% of recorded neurons, including bushy and stellate cells. The latency of most IPSPs (88%) was in the range 3.3-7.6 ms, consistent with mono- and disynaptic transmission from the contralateral CN. The IPSPs had an average amplitude of 2.6 +/- 1.9 mV and were blocked by strychnine suggesting their glycinergic nature. These data, together with our similar findings in other CN subdivisions, indicate that principal cells of the CN contribute to binaural interactions at earliest stages of acoustic processing.
