Dynamic Oculomotor Reaction

Abstract

Publisher Summary The functional importance of the reticular formation for any motor activities including vestibular nystagmus is obvious. However, the fact that the excitatory postsynaptic potentials (EPSP) and the inhibitory postsynaptic potential (IPSP) are produced highly synchronously in the antagonistic motoneurons at the quick phase should be stressed. This indicates that a synchronous arrival of excitatory and inhibitory impulses at the motoneuron determines the onset of the quick phase. The synchronism may not be well explained by multineuronal chains in the reticular formation mediating the quick contraction. It is likely that delayed impulses through multineuronal chains intensify the synaptic activities as suggested by Lorente de No, it can at present neither be accepted nor rejected that the possibility that inhibitory and excitatory reticular neurons project directly to the ocular motoneurons and produce the synchronized IPSP and EPSP in a reciprocal fashion as vestibular nuclei neurons may do. It is not known whether the synaptic events in optokinetic nystagmus or saccades are similar to those in vestibular nystagmus.