| 研究実績の概要 |
In order to examine the heterosynaptic interactions between active presynaptic inputs in hippocampal slice cultures, rabies virus tracing technique was implemented to identify CA3 presynaptic neurons that convergently targeted a common CA1 postsynaptic neuron. Although the labelling itself was successful, infected neurons were found to degenerate over several days and consequently it was difficult to assess the functional properties of the convergent connections by electrophysiology. Therefore, a change of strategy was required. To this end, the use of acute hippocampal slices that better preserved the highly organized native connectivity pattern was considered. In particular, acute slices allowed for sampling of independent sets of CA3 to CA1 inputs without the need for viral tracing. Minimal stimulation of two sets of non-overlapping presynaptic inputs showed highly variable failure events, and indicated the heterogeneity of presynaptic efficacy between convergent connections. Pilot experiments showed that stimulation of one set of inputs could induce long-term plasticity and that this produced heterosynaptic changes in the non-stimulated input.
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