Schmitt U, Cross R, Pazdernik T L, Sabel B A
Institute of Medical Psychology, Otto-von-Guericke University of Magdeburg Medical School, Germany.
Exp Neurol. 1996 May;139(1):17-24. doi: 10.1006/exnr.1996.0076.
A mild crush of the adult rat optic nerve serves as a model to study the restoration of function after traumatic brain injury. It causes a progressive degeneration of retinal ganglion cells, but visually guided behavior is partially restored within 2-3 weeks. The purpose of this study was to determine to what extent local cerebral glucose use (LCGU) decreases and if it recovers in retinofugal targets following unilateral optic nerve crush. At intervals of 2, 9, and 22 days after crush, LCGU was monitored in rats in which the visual system was stimulated by a strobe-light and pattern. In the ipsilateral retinofugal targets there was only a minimal loss of LCGU use, but in the contralateral retinofugal targets, LCGU was reduced at Postlesion Day 2: to 50% in the superior colliculus (SC), to 60% in the lateral geniculate nucleus of the thalamus (LGN), and to 87% in the visual cortex. On Postoperative Days 9 and 22 we observed a partial restoration of LCGU in the contralateral SC and LGN to 68 and 79%, respectively. As recovery of visual performance is known to follow a similar time course, we conclude that restoration of metabolic activity in target structures may contribute to the restoration of vision after optic nerve crush.
成年大鼠视神经轻度挤压伤可作为研究创伤性脑损伤后功能恢复的模型。它会导致视网膜神经节细胞进行性退化，但视觉引导行为在2 - 3周内会部分恢复。本研究的目的是确定单侧视神经挤压伤后，视网膜神经纤维投射目标区域的局部脑葡萄糖利用（LCGU）下降的程度以及是否恢复。在挤压伤后的第2、9和22天，对通过频闪灯和图案刺激视觉系统的大鼠进行LCGU监测。在同侧视网膜神经纤维投射目标区域，LCGU利用仅有轻微损失，但在对侧视网膜神经纤维投射目标区域，损伤后第2天LCGU降低：在上丘（SC）降至50%，在丘脑外侧膝状体核（LGN）降至60%，在视觉皮层降至87%。在术后第9天和第22天，我们观察到对侧SC和LGN的LCGU分别部分恢复至68%和79%。由于已知视觉功能的恢复遵循类似的时间进程，我们得出结论，目标结构中代谢活动的恢复可能有助于视神经挤压伤后视力的恢复。
