Peterson G M, Lanford G W, Powell E W
Department of Anatomy and Cell Biology, East Carolina University School of Medicine, Greenville, NC 27858-4354.
Brain Res Bull. 1990 Jul;25(1):129-37. doi: 10.1016/0361-9230(90)90263-y.
Neurons in the medial septum (MS) and vertical limb of the diagonal band (vDB) undergo degenerative changes following transection of their axons. These changes have been well studied by histological techniques such as Nissl stains and immunocytochemistry. A dramatic loss of stained neurons occurs following axotomy and this has been interpreted as indicative of neuronal death. However, since the staining intensity and the size of affected neurons may be reduced by axotomy, it is possible that the apparent neuronal death may actually be due to a decrease in somal size or the ability to detect neurons by routine histological methods. The present study describes the effects of axotomy on MS and vDB neurons which have been labeled by hippocampal injections of the retrograde tracer, Fluoro-Gold (FG), prior to transection of the fimbria-fornix and supracallosal stria. The number of FG-labeled neurons in the MS decreased by 21% at three weeks, 36% at six weeks, and 31% at ten weeks after fimbria-fornix transection. The reduction was statistically significant at 6 and 10 weeks. The number of FG-labeled neurons in the vDB showed no reduction at three weeks but was decreased by 31% and 37% at six and ten weeks, respectively. This was statistically significant only at 10 weeks. By comparison, the number of neurons immunoreactive for choline acetyltransferase (ChAT) was reduced by 75-80% at these time points. The size (area and diameter) of FG-labeled somata decreased in both the MS and vDB within three weeks following fimbria-fornix transection and remained relatively constant at the six- and ten-week time points.(ABSTRACT TRUNCATED AT 250 WORDS)
内侧隔区（MS）和斜角带垂直支（vDB）中的神经元在其轴突横断后会发生退行性变化。这些变化已通过诸如尼氏染色和免疫细胞化学等组织学技术得到了充分研究。轴突切断后，染色神经元会显著减少，这被解释为神经元死亡的迹象。然而，由于轴突切断可能会降低受影响神经元的染色强度和大小，所以表面上的神经元死亡实际上可能是由于胞体大小减小或常规组织学方法检测神经元的能力下降所致。本研究描述了在切断穹窿-海马伞和胼胝体上缘纤维之前，通过向海马注射逆行示踪剂荧光金（FG）标记内侧隔区和斜角带垂直支神经元后，轴突切断对这些神经元的影响。在切断穹窿-海马伞后3周，内侧隔区中FG标记的神经元数量减少了21%，6周时减少了36%，10周时减少了31%。在6周和10周时，这种减少具有统计学意义。斜角带垂直支中FG标记的神经元数量在3周时没有减少，但在6周和10周时分别减少了31%和37%。仅在10周时具有统计学意义。相比之下，在这些时间点，对胆碱乙酰转移酶（ChAT）免疫反应阳性的神经元数量减少了75 - 80%。在切断穹窿-海马伞后3周内，内侧隔区和斜角带垂直支中FG标记的胞体大小（面积和直径）均减小，在6周和10周时间点保持相对稳定。（摘要截断于250字）
