[The functional connection among the "zusanli"-spinal dorsal horn neurons-trigeminal sensory nucleus of rats].

Electrical stimulation of Zusanli (ST36) point and Trigeminal Sensory Nucleus (TSN) as well as microelectrode recording from the laminae II - VI of the lumbar spinal dorsal horn have been used on the pentobarbital anesthetized rats, finding and identifying 142 spinal neurons responding to the stimulation of both ST36 and TSN. Among them, 29 responded antidromically to TSN; the others, responded orthodromically to TSN; These neurons distributed in the L2-S1 segments, the most in the L3-L6 segments, and in the laminae III-V, occasionally in the laminae II and VI in the spinal dorsal horn, the LTM and WDR neurons were 50% respectively of them. The results indicate that (i) single spinal dorsal horn neurons receives ST36 afferent input and then conveys it to the TSN; (ii) some spinal dorsal horn neurons receive, in turn, innervation from TSN; (iii) The convergence and integration between ST36 and TSN inputs might occur in the spinal dorsal horn neurons.