2024-03-29T02:01:07Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/628892022-11-17T02:08:08Zhdl_2115_20039hdl_2115_116Spatial dynamics of action potentials estimated by dendritic Ca2+ signals in insect projection neuronsOgawa, HirotoMitani, RurikoCalcium imagingDendriteInsect neuronLateralitySpike initiation zoneSpike propagation400The spatial dynamics of action potentials, including their propagation and the location of spike initiation zone (SIZ), are crucial for the computation of a single neuron. Compared with mammalian central neurons, the spike dynamics of invertebrate neurons remain relatively unknown. Thus, we examined the spike dynamics based on single spike-induced Ca2+ signals in the dendrites of cricket mechanosensory projection neurons, known as giant interneurons (GIs). The Ca2+ transients induced by a synaptically evoked single spike were larger than those induced by an antidromic spike, whereas subthreshold synaptic potentials caused no elevation of Ca2+. These results indicate that synaptic activity enhances the dendritic Ca2+ influx through voltage-gated Ca2+ channels. Stimulation of the presynaptic sensory afferents ipsilateral to the recording site evoked a dendritic spike with higher amplitude than contralateral stimulation, thereby suggesting that alteration of the spike waveform resulted in synaptic enhancement of the dendritic Ca2+ transients. The SIZ estimated from the spatial distribution of the difference in the Ca2+ amplitude was distributed throughout the right and left dendritic branches across the primary neurite connecting them in GIs.Journal Articleapplication/pdfhttp://hdl.handle.net/2115/62889https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/62889/1/Ogawa%26Mitani_manuscript.pdf0006-291XBiochemical and Biophysical Research Communications46721851902015enginfo:pmid/26456645info:doi/10.1016/j.bbrc.2015.10.021author