在蟾蜍脊髓诱发电位的研究中,刺激腓肠肌与胫前肌向心神经在腰膨大部位出现恒定的电反应,即兴奋性突触电位。该突触的突触前成分是肌向心神经纤维;突触后成分是运动神经元向背侧延伸的树突。两者可能在背柱形成突触,为运动神经元的背侧树突突触(Dorsal dendritic synapse)。这一判断支持和补充了Brookhart及Szekely的 In the study of toad spinal cord evoked potential, the stimulation of the gastrocnemius and tibialis anterior muscle to the cardiac nerve in the lumbar enlargement of a constant electrical response, excitatory synaptic potential. The presynaptic presynaptic component of the synapses is a myofibulatory nerve fiber; the postsynaptic component is a dendritic extending to the dorsal aspect of motor neurons. Both may form synapses in the dorsal column, the dorsal dendritic synapse of motor neurons. This judgment supports and complements Brookhart and Szekely