摘要The back-propagating action potential(bpAP)is crucial for neuronal signal integration and synaptic plastic-ity in dendritic trees.Its properties(velocity and amplitude)can be affected by dendritic morphology.Due to limited spa-tial resolution,it has been difficult to explore the specific propagation process of bpAPs along dendrites and examine the influence of dendritic morphology,such as the dendrite diameter and branching pattern,using patch-clamp record-ing.By taking advantage of Optopatch,an all-optical elec-trophysiological method,we made detailed recordings of the real-time propagation of bpAPs in dendritic trees.We found that the velocity of bpAPs was not uniform in a single den-drite,and the bpAP velocity differed among distinct dendrites of the same neuron.The velocity of a bpAP was positively correlated with the diameter of the dendrite on which it prop-agated.In addition,when bpAPs passed through a dendritic branch point,their velocity decreased significantly.Similar to velocity,the amplitude of bpAPs was also positively corre-lated with dendritic diameter,and the attenuation patterns of bpAPs differed among different dendrites.Simulation results from neuron models with different dendritic morphology cor-responded well with the experimental results.These findings indicate that the dendritic diameter and branching pattern significantly influence the properties of bpAPs.The diversity among the bpAPs recorded in different neurons was mainly due to differences in dendritic morphology.These results may inspire the construction of neuronal models to predict the propagation of bpAPs in dendrites with enormous vari-ation in morphology,to further illuminate the role of bpAPs in neuronal communication.