Identification and classification of excitatory and inhibitory profiles in EVN neurons.

<p><b>(A)</b> Schematic view of transversely sectioned mouse brainstem. Inset shows map of recording sites (22/23 recorded neurons). <i>VN</i>: vestibular nucleus; <i>G7n</i>: genu of seventh cranial nerve (facial nerve); <i>6n</i>: sixth cranial nerve nucleus (abducens nucleus); <i>4V</i>: fourth ventricle; <i>EVN</i>: efferent vestibular nucleus. <b>(B)</b><i>Top trace</i>: EPSCs recorded under normal conditions before the addition of drugs. <i>Second trace</i>: addition of CNQX (10 μM) and TTX (1 μM). <i>Third trace</i>: mIPSCs recorded under normal conditions before the addition of drugs. <i>Bottom trace</i>: addition of strychnine (1 μM) and bicuculline (10 μM) abolished all synaptic activity. Some neurons received excitatory inputs in conjunction with: GABA_AR-mediated events <b>(C)</b><i>Bottom trace</i>: addition of bicuculline to the bath abolished activity remaining after the addition of TTX and CNQX (<i>second trace</i>); GlyR-mediated events <b>(D)</b><i>Bottom trace</i>: addition of strychnine abolished remaining activity following the addition of TTX and CNQX (<i>second trace</i>). <b>(E)</b> Other neurons received a combination of mIPSCs in addition to EPSCs. In these neurons, the addition of bicuculline reduced the frequency of synaptic activity (<i>third trace</i>) that was abolished by addition of strychnine (<i>bottom trace</i>). Scale bar in <b>(B)</b> is the same for all traces. <b>(F)</b> Frequencies of EPSCs and mIPSCs per cell calculated over a period of 30 seconds under the influence of excitatory and inhibitory synaptic activity blockers.