Synaptic reorganization in the medial amygdaloid nucleus after lesion of the accessory olfactory bulb of adult rat. II. New synapse formation in the medial amygdaloid nucleus by fibers from the bed nucleus of the stria terminalis

The rearrangement of terminations from the bed nucleus of stria terminalis (BST) was examined in the medial amygdaloid nucleus (MAN) at 2 months following the lesion of the accessory olfactory bulb (AOB) using an electron microscopy and degeneration study. At 2 days following a BST lesion, the number of degenerating synapses was 0.7 ± 0.1 (mean±S.E.M.) per unit area (2500 μm² in the molecular layer, and 3/0 ± 0.3 in the cellular part. At 2 months after an AOB lesion, the degenerating synapses from the AOB had completely disappeared from the MAN. The BST was then lesioned at 2 months after the AOB lesion and, 2 days following this BST lesion, the degenerating synapses were counted in MAN. The numbers observed were 3.3 ± 0.6 per unit area in the molecular layer and 4.5 ± 0.4 in the cellular part. Therefore, the number of these degenerating synapses increased significantly within the molecular layer, though, in the cellular part the number of synapses was not significantly elevated over control. No differences in postsynaptic profiles (ratio of synapses on dendritic spine to dendritic shaft) were observed after the AOB lesion. These results indicate that the BST fibers formed new synapses in the molecular layer following the denervation of AOB fibers. The possibility of new synapse formation by other afferent fibers in addition to the AOB fibers is discussed as is the relationship between lesion induced synaptic reorganization and functional recovery after injury.     

基于人工嗅觉的呈香物质识别方法

研究了人工嗅觉在物质识别中的应用，概述了使用模式识别辨别物质气味的基本原理，详细介绍了人工嗅觉系统的硬件设计，算法和软件实现方法，最后使用本系统对不同香气物质进行了识别，取得了较好的结果。     

Immunocytochemical demonstration of neural cell adhesion molecule (NCAM) along the migration route of luteinizing hormone-releasing hormone (LHRH) neurons in mice.

Contact between the developing forebrain and the ingrowing central processes of the olfactory, vomeronasal and terminal nerves is preceded by a migration of neural cell adhesion molecule (NCAM)-immunoreactive cells from the epithelium of the olfactory pit and the formation of an NCAM-immunoreactive cellular aggregate in the mesenchyme between the olfactory pit and the forebrain. The axons of the olfactory, vomeronasal, and terminal nerves, also NCAM-immunoreactive, grow into the cellular aggregate, which as development proceeds, becomes continuous with the rostral tip of the forebrain. The lateral and more rostral part of the cellular aggregate receives the ingrowing axons of the olfactory nerves and becomes the olfactory nerve layer of the olfactory bulb. The medial, more caudal part receives the central processes of the vomeronasal and terminal nerves. The vomeronasal nerve ends in the accessory olfactory bulb. The central processes of the terminal nerve end in the medial forebrain. Luteinizing hormone-releasing hormone (LHRH)-immunoreactive neurons, like the vomeronasal and terminal nerves, originate from the medial part of the olfactory pit. These LHRH cells migrate into the brain along and within a scaffolding formed by the NCAM-immunoreactive axons of the vomeronasal and terminal nerves, and they are never seen independent of this NCAM scaffold as they cross the nasal lamina propria. The results suggest that: (1) NCAM is likely to be necessary for scaffold formation, and (2) the scaffold may be essential for the subsequent migration of LHRH neurons into the brain. Because they aggregate, migrating LHRH-immunoreactive neurons, on which we did not detect NCAM immunoreactivity, may interact via other cell adhesion molecules (CAM). Inasmuch as the interaction between the LHRH-immunoreactive neurons and the NCAM-immunoreactive scaffold is heterotypic, the possibility of a heterophilic (NCAM to other CAM) interaction is not ruled out. These findings focus our attention on the functional role of NCAM in this migratory system.     

The development of glial fibrillary acidic protein-positive cells and the appearance of laminin-like immunoreactivity in fetal olfactory bulb transplants

Embryonic rat olfactory bulbs were transplanted into the site vacated by aspiration of an olfactory bulb from a neonatal rat. This paper presents our findings related to the development of glial fibrillary acidic protein (GFAP) positive (+ve) glial cells and the appearance of laminin-like immunoreactivity in these transplants. The GFAP + ve glial cells formed perivascular end-feet on the invading vasculature and formed a glia limitans along the glia surface of the transplant. This reconstituted glia limitans was continuous with that of the host brain, there being no glia limitans at the donor-host interface. Thus, the donor tissue was well-integrated with that of the host brain.     

TrKA和p75神经营养因子受体在嗅神经母细胞瘤的表达

目的 :探讨TrKA和p75神经营养因子受体在嗅神经母细胞瘤的表达及其临床意义。方法 :应用免疫组化和双荧光标记法对 10例鼻腔嗅神经母细胞瘤及 5例正常鼻腔嗅黏膜及 5例鼻咽癌组织进行TrKA和p75神经营养因子受体检测。结果 :免疫组化检测发现 10例鼻腔嗅神经母细胞瘤TrKA和p75蛋白均呈阳性表达 ,5例正常鼻腔嗅黏膜及 5例鼻咽癌组织均为阴性表达 ;双荧光标记显示所有肿瘤组织中TrKA和p75蛋白均在同一细胞表达。结论 :TrKA和p75神经营养因子受体的过度表达可能与嗅神经母细胞瘤的发生和发展有关 ;TrKA和p75神经营养因子受体检测可作为嗅神经母细胞瘤的一种辅助诊断方法     

嗅沟脑膜瘤术式选择及长期临床预后随访

目的分析嗅沟脑膜瘤的手术治疗和随访结果。方法收集20例嗅沟脑膜瘤手术病例,并分析其临床表现及随访结果。结果嗅沟脑膜瘤大多以精神症状、视觉障碍和嗅觉减退为首发症状,9例行冠状切口,4例行半冠状切口,分块切除肿瘤,5例翼点入路,1例纵裂入路。1例眶上入路,SimpsonI级切除6例。SimpsonⅡ级切除13例,SimpsonⅢ级切除1例,预后良好,1例复发。随访时间1~6年(平均3.1年),术前术后均保留嗅觉的为2例,精神状态改善18(91%)和视力障碍改善的15(75%)。1例(5%)复发再次手术。结论术式的选择取决诸多因素,预后取决于手术中的组织保护。     

A learned odor decreases the number of Fos-immunopositive granule cells in the olfactory bulb of young rats

Olfactory stimulation evokes a column of activity within the olfactory bulb extending from the glomerular layer to the granule cell layer that can be visualized with 2-deoxyglucose autoradiography, optical imaging, Fos protein immunohistochemistry and c-fos mRNA in situ hybridization. The Fos response to odors is typified by the activity of relatively few juxtaglomerular cells, which often occur in foci, and a large number of granule cells extending through much of the bulb. In this study, we characterized the granule cell response to an odor for which young rats had acquired a preference. Fos-like immunoreactive granule cells were quantified by image analysis, and densely stained cells were counted in a region previously shown to be responsive to peppermint odor. We found that odor-trained pups have about half the number of Fos-immunopositive superficial granule cells which respond to a learned odor than do control pups. We then determined whether there was a correlation between the juxtaglomerular cell response and the response of the superficial granule cells deep to those glomerular layer cells. We found a positive correlation between the number of juxtaglomerular cells and the number of granule cells demonstrating Fos immunoreactivity in both control and trained pups, a relationship that changed with early olfactory training.