Electrophysiologic evidence for involvement of acetylcholine as a neurotransmitter in the lateral vestibular nucleus

Monosynaptic spike generation of lateral vestibular nucleus (LVN) neurons with vestibular nerve stimulation in cats was inhibited by microiontophoretic atropine and gamma-aminobutyric acid (GABA). Spontaneous firing of the LVN monosynaptic neuron was increased by iontophoretic acetylcholine and glutamate. Atropine inhibited acetylcholine-induced firing without affecting glutamate-induced firing, while GABA blocked spike generation produced by acetylcholine and glutamate. Acetylcholine probably plays a role in transmission from the vestibular nerve to the LVN monosynaptic neurons.