Beitz A J
J Comp Neurol. 1985 Jul 22;237(4):445-59. doi: 10.1002/cne.902370403.
The midbrain periaqueductal gray is a functionally heterogeneous region which plays an important role in pain modulation. Despite the heterogeneity considerable controversy exists regarding the presence or absence of morphological subdivisions within the region. The present study was designed to evaluate the possibility of morphological subdivisions within the rat periaqueductal gray by using a statistical cluster analysis system. In addition both qualitative and quantitative data concerning neuronal size, shape, and density were obtained. On the basis of measurements of over 12,000 neurons in two planes of section, the mean neuronal length of cell bodies in this region was 14.82 microns and the mean neuronal area was 95.59 microns squared . The mean neuronal density was found to be 16,284 cells per mm3. Neuronal density decreased from rostral to caudal in the periaqueductal gray. The data obtained from cluster maps suggest the presence of four subdivisions within this midbrain region. The medial subdivision contains the smallest neurons and exhibits the lowest cell density. The dorsolateral and ventrolateral divisions contain the largest neurons while the dorsal division displays the highest packing density. These results are discussed in light of recent receptor binding and immunohistochemical studies of this region.
中脑导水管周围灰质是一个功能异质性区域，在疼痛调节中起重要作用。尽管存在异质性，但关于该区域内是否存在形态学细分仍存在相当大的争议。本研究旨在通过使用统计聚类分析系统评估大鼠导水管周围灰质内形态学细分的可能性。此外，还获得了有关神经元大小、形状和密度的定性和定量数据。基于在两个切片平面上对12000多个神经元的测量，该区域细胞体的平均神经元长度为14.82微米，平均神经元面积为95.59平方微米。发现平均神经元密度为每立方毫米16284个细胞。导水管周围灰质的神经元密度从吻侧到尾侧降低。从聚类图获得的数据表明该中脑区域内存在四个细分。内侧细分包含最小的神经元，且细胞密度最低。背外侧和腹外侧分区包含最大的神经元，而背侧分区显示最高的堆积密度。根据该区域最近的受体结合和免疫组织化学研究对这些结果进行了讨论。
