Byrd C A
Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008, USA.
Brain Res. 2000 Jun 2;866(1-2):92-100. doi: 10.1016/s0006-8993(00)02252-6.
The influence of the olfactory organ on maintenance of olfactory bulb structure was examined in zebrafish, using peripheral deafferentation. This fish provides a model in which the olfactory organ is easily accessible for removal, the animals easily survive the surgery, and the olfactory bulbs are small enough to allow rigorous analysis of the resulting effects. Unilateral olfactory organ ablations were performed on anesthetized adult zebrafish using a small-vessel cautery iron. Fish were allowed to survive for 1, 3, or 6 weeks following the procedure. Analysis of deafferented animals revealed that most, if not all, of the olfactory organ was missing on the ablated side, and the structure did not regenerate. The morphology of the olfactory bulb was affected notably by the removal of its primary afferent innervation. The olfactory nerve layer was diminished at 1 week and absent by 3 weeks post-deafferentation. At all of the survival times the deafferented bulb appeared significantly smaller at the gross level, and there was a statistically significant effect on bulb size and cell number after 6 weeks. Tyrosine hydroxylase expression, as revealed by immunohistochemistry, was decreased noticeably on the ablated side. In conclusion, the olfactory organ is important in the preservation of normal olfactory bulb anatomy and neurochemistry in adult zebrafish. Thus, the influence of the periphery does not end with the formation of the mature olfactory bulb.
利用外周去传入神经法，在斑马鱼中研究了嗅觉器官对嗅球结构维持的影响。这种鱼提供了一个模型，在该模型中，嗅觉器官易于切除，动物能轻松挺过手术，且嗅球足够小，便于对所产生的影响进行严格分析。使用小型血管烧灼烙铁对麻醉的成年斑马鱼进行单侧嗅觉器官切除。术后让鱼存活1、3或6周。对去传入神经的动物进行分析发现，在切除侧，大部分（如果不是全部）嗅觉器官缺失，且该结构未再生。嗅球的形态受到其主要传入神经支配缺失的显著影响。去传入神经后1周，嗅神经层变薄，3周后消失。在所有存活时间，去传入神经的嗅球在大体水平上明显变小，6周后对嗅球大小和细胞数量有统计学上的显著影响。免疫组织化学显示，切除侧酪氨酸羟化酶表达明显降低。总之，嗅觉器官对成年斑马鱼正常嗅球解剖结构和神经化学的维持很重要。因此，外周的影响并不随着成熟嗅球的形成而结束。
