ABSTRACT
46 rabbits were divided into two groups. HRP was injected into one of the 7 segments of spinal cord (T_(11,12)、L_(1,2)、S(2～4)) unilaterally in 42 adult rabbits in the experimental group. HRP was also injected into the vein of the ear (2 cases) and cerebrospinal fluid (2 cases) as the control group. The hypothalamus were cut at 40 ?m. The sections were incubated with BDHC and OD by Mesulam's 8th and Edward's procedures. Labeled cell were found in the medial basal hypothalamus (MBH), ventromedial nucleus (VM), paraventricular nucleus (PV), dorsomedial nucleus (DM), posterior nucleus (PN), supraoptic nucleus (SN), lateral nucleus (LN), anterior nucleus (AN), perifornical nucleus and zona incerta in all cases. The PV was most heavily labeled. The LN, PN and DM were less so. Some labeled cells were found in the MBH, VM and AN. A few labeled cells were present in the SN. Labeled terminal and preterminal axons were found in the dorsolateral margin of the PV and in the LN、PN and MBH.Labeled terminals of the hypothalamus, which were discovered in this study, has not mentioned in the literature available to us. This study demonstrated reciprocal projection between the hypothalamus and the segments of the spinal cord innervating pelvic organs.