QUANTITATIVE ANALYSIS OF SUBSTANCE PCONTAINING NERVE FIBERS AND CELLS IN THE NUCLEUS OF DORSOLATERAL FUNICULUS OF THE RAT / 解剖学报

Using immunocytochemical method and image analysis computer system, quantitative analysis of substance P (SP) containing nerve fibers and neurons in the nucleus of dorsolateral funiculus (NDLF) was studied in the rat spinal cord. Under light microscope, in the white substance of the whole length of the spinal cord, a concentrated triangular or cuneiform area of SP-immunoreactive positive fibers and cells could be observed in the NDLF region. Using the image anlysis computer system (IBAS 2000) the outline of the whole SP stained area in the NDLF was drawn with a light point of the Mouse and this whole area was measured and named as the reference area (REFAREA). We selected the optimal gray level of the image in NDLF region by the Interactive Segment as the threshold. The sum of the SP labelled areas was called the field area (FAREA). The ratio of the FAREA to REFAREA (AREA%) represented the percentage of density to area of the SP labelled substance in NDLF. The mean value of REFAREA, FAREA, and AREA% are: 47931.38?m~2, 21995.25?m~2, and 45.89% in the cervical segments; 31575.15 ?m~2, 7646.85?m~2, and 24.22% in the thoracic region; 26889.89?m~2, 8470.66?m~2, and 31.50% in the lumbar and sacral segments, respectively. In short, according to the density of SP positive fibers and neurons in NDLF and the size of their distributive area, the sequence of density and size from highest to lowest is: cervical, lumbar, sacral and thoracic segments, with the lowest one at thoracic 8-10 segments.

THE ORIGINS OF THE DESCENDING PRO-PRIOSPINAL TRACT AND THE CONNEC-TIONS OF THE NUCLEUS DORSOLA-TERAL FUNICULUS IN THE SPINAL CORD OF THE RAT / 解剖学报

HRP solution was injected into the right side of the thoracic spinal cord of the rat with a micropipette to observe the neurons which give rise to the descending propiospinal tract. Labeled neurons were distributed throughout the bilateral Rexed's laminae Ⅰ-Ⅹ of the spinal cord in the segments rostral to the site of HRP application. The greatest number of the labeled cells were consistently found in lamina Ⅶ (including the intermediolateral nucleus), and then in laminae Ⅷ and Ⅳ. Our results verified the existence of the nucleus of the dorsolateral funiculus and its intraspinal connections in the spinal cord of the rat. This nucleus gives rise to the descending projections to the lower spinal segments.