OPTICAL IMAGING OF THE SPATIOTEMPORAL PATTERNS OF THE NEURONAL ACTIVITY IN VESTIBULAR NUCLEUS / 解放军医学杂志

ABSTRACT

To explore the spatiotemporal patterns of the neuronal excitatory propagation in vestibular nucleus, brainstem sections were prepared from postnatal 1～5 day mice, and stained with RH155, which was an light absorbent voltage sensitive dye, for 20 minutes. A multiple site optical recording system was used for optical imaging of the evoked responses after electrical stimulation of the vestibular nerve. After stimulation of the vestibular nerve, optical responses were revealed in the vestibular nucleus. There was propagation of excitation in both ipsilateral vestibular nucleus and contralateral vestibular nucleus after ipsilateral vestibular nerve stimulation. These optical signals were wave length dependent. The optical signals consisted of two components the spike like fast signal and long duration slow signal. All the responses were abolished by 20?mol/L tetrodotoxin (TTX). The effect of TTX was irreversible. The slow signals were entirely eliminated after the application of Ca 2+ free solution. The effect of Ca 2+ free solution was reversible. These results suggested that the slow signal might be postsynaptic excitation potential. The present study indicated that the use of optical recording to reveal visually the synaptic transmission of afferent input in vestibular nucleus in the brainstem was feasible.