Abstract
In an accompanying study, using a multiple-site optical recording technique with a voltage-sensitive dye, we examined the developmental organization of the olfactory pathway in the embryonic chick forebrain, and showed that functional synaptic transmission in the olfactory bulb was expressed at around E7. It is known that odor stimuli elicit oscillatory events in the olfactory bulb in various species. We found that oscillatory activity was also generated in the chick olfactory bulb during embryogenesis. At early stages of development (E7-E8), postsynaptic response-related optical signals evoked by olfactory nerve stimulation exhibited a simple monophasic waveform that lasted a few seconds. As development proceeded, the pattern of the optical signal became complicated, and oscillatory activity was observed in a later phase of the postsynaptic response. The oscillation was restricted to the olfactory bulb, and this spatial pattern was different from that of the propagating wave activity termed the depolarization wave. We examined spatio-temporal patterns of the oscillatory activity in different stages, and studied its developmental dynamics. [J Physiol Sci. 2006;56 Suppl:S169]
