Abstract: A total of 53 neurons responding to cervical dorsal column stimulation were intra- and extracellularly recorded and identified mainly in laminae Ⅱ-Ⅵ of the lumbar spinal dorsal horn in anesthetized rats. Of them, 39 units were dorsal column postsynaptic (DCPS) neurons in terms of their responses meeting criteria for antidromicity. The antidromic responses of 15 of these neurons were followed by one or more synaptic responses with different intervals, suggesting some DCPS neurons receive decending innervation from the dorsal column nuclei (DCN). The other 21 units merely showed postsy- naptic responses to dorsal column stimulation and might thus be interneurons innervated from DCN in the dorsal horn.

Key words: dorsal column postsynaptic neuron, spinal interneuron, dorsal column nuclei, antid romic stimulation, rat