Abstract
Despite molecular identification of a large number of "presynaptic" proteins, their functions remain largely undetermined. To address this issue, we developed a novel method to directly evaluate the effect of gene silencing by RNA interference on the central neurotransmission in situ. In anesthetized young Wistar rats, either of (1) synthetic siRNA against the gene coding adenosine A1 receptors (Adora1), (2) siRNA of random sequence or (3) vehicle, was introduced to the nodose ganglion (NG) by electroporation. Introduction of siRNA labeled with Cy3 revealed an introduction efficiency of ∼85% of the nodose ganglion neurons. The number of cells was not significantly affected by introduction. Three to nine days after siRNA delivery, adora1 expression in the NG decreased by >80% of non-treated NG. The presynaptic inhibition by adenosine of the transmission from primary afferents to the second-order neurons, as evaluated by electrophysiological recording in the brainstem slice preparation, was markedly attenuated on 11 to 13 days after siRNA delivery. This approach provides a promising strategy for the analysis of the functional role of presynaptic proteins in the brain synapses. [J Physiol Sci. 2007;57 Suppl:S149]
