PLASTICITY OF CONNECTIONS OF THE OLFACTORY SENSORY NEURON - REGENERATION INTO THE FOREBRAIN FOLLOWING BULBECTOMY IN THE NEONATAL MOUSE
PLASTICITY OF CONNECTIONS OF THE OLFACTORY SENSORY NEURON - REGENERATION INTO THE FOREBRAIN FOLLOWING BULBECTOMY IN THE NEONATAL MOUSE
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DOI：
10.1016/0306-4522(79)90002-2
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发表时间：
1979-01-01
期刊：
影响因子：
3.3
通讯作者：
MONTIGRAZIADEI, GA
中科院分区：
文献类型：
--
作者：
GRAZIADEI, PPC;LEVINE, RR;MONTIGRAZIADEI, GA
新生小鼠接受单侧嗅球切除术，其中包括主嗅球和副嗅球。从存活5天开始，额叶皮质明显向前移位，进入之前被球占据的空腔。由于嗅球切除术和随之而来的嗅觉轴突损伤，嗅核周体发生逆行变性。新的神经元，然后重建干细胞内的嗅神经上皮。术后20天，新的嗅觉轴突已达到筛板的水平，并通过30天的纤维已经渗透到端脑，并在宿主组织内形成典型的肾小球结构。纤维被定向到古皮层或necortex，在那里它们被观察到靠近大的皮层神经元。肾小球的形成在整个研究过程中持续存在（180天），并在皮质组织内显示出扩张，直至存活60天。这些纤维和肾小球结构的嗅觉鉴定证实了免疫组化技术，使用抗血清的特定嗅觉蛋白。超微结构的观察清楚地表明，典型的肾小球模式的结构，并表现出突触之间的接触的感觉终端和树突状进程，尚未确定，起源于周围的大脑基质。在嗅球切除和嗅神经元逆行变性后，细胞可以在缺乏正常靶点的情况下再生。新生的轴突可以穿透大脑皮层，形成典型的肾小球结构和相应的感觉突触。这一发现表明嗅觉系统和大脑皮层具有一种意料之外的可塑性。
Neonatal mice underwent unilateral bulbectomy, which included the main and accessory olfactory bulbs. From 5 days of survival onward, there was a marked anterior displacement of the frontal cortex into the cavity previously occupied by the bulb. As a result of the bulbectomy and consequent damage to olfactory axons, the olfactory perikarya underwent retrograde degeneration. New neurons were then reconstituted from stem cells within the olfactory neuroepithelium. By 20 postoperative days the new olfactory axons had reached the level of the lamina cribrosa and by 30 days the fibers had penetrated into the telencephalon and had formed typical glomerular structures within the host tissue. Fibers were directed to the paleo- or necortex where they were observed in close proximity to large cortical neurons. The formation of glomeruli persisted over the course of the study (180 days) and showed an expansion within the cortical tissue up to 60 days of survival. The identification of these fibers and glomerular structures as olfactory was confirmed by immunohistochemical techniques using antisera to the specific olfactory protein. Ultrastructural observations clearly indicated the typical glomerular pattern of the structures and demonstrated synaptic contacts between the sensory terminals and dendritic processes, as yet unidentified, originating from the surrounding cerebral matrix. Following bulbectomy and retrograde degeneration of olfactory neurons, the cells can regenerate in the absence of their normal target. The newly formed axons can penetrate the cerebral cortex and form typical glomerular structures and corresponding sensory synapses. The findings suggest an unsuspected degree of plasticity in the olfactory system and in the cerebral cortex.