A novel animal model of partial optic nerve transection established using an optic nerve quantitative amputator.

BACKGROUND: Research into retinal ganglion cell (RGC) degeneration and neuroprotection after optic nerve injury has received considerable attention and the establishment of simple and effective animal models is of critical importance for future progress. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, the optic nerves of Wistar rats were semi-transected selectively with a novel optic nerve quantitative amputator. The variation in RGC density was observed with retro-labeled fluorogold at different time points after nerve injury. The densities of surviving RGCs in the experimental eyes at different time points were 1113.69±188.83 RGC/mm² (the survival rate was 63.81% compared with the contralateral eye of the same animal) 1 week post surgery; 748.22±134.75/mm² (46.16% survival rate) 2 weeks post surgery; 505.03±118.67/mm² (30.52% survival rate) 4 weeks post surgery; 436.86±76.36/mm² (24.01% survival rate) 8 weeks post surgery; and 378.20±66.74/mm² (20.30% survival rate) 12 weeks post surgery. Simultaneously, we also measured the axonal distribution of optic nerve fibers; the latency and amplitude of pattern visual evoke potentials (P-VEP); and the variation in pupil diameter response to pupillary light reflex. All of these observations and profiles were consistent with post injury variation characteristics of the optic nerve. These results indicate that we effectively simulated the pathological process of primary and secondary injury after optic nerve injury. CONCLUSIONS/SIGNIFICANCE: The present quantitative transection optic nerve injury model has increased reproducibility, effectiveness and uniformity. This model is an ideal animal model to provide a foundation for researching new treatments for nerve repair after optic nerve and/or central nerve injury.

Microsurgical anatomy of the greater superficial petrosal nerve.

OBJECTIVE: To clarify the orientation, classification, and relationships of the greater superficial petrosal nerve (GSPN), and to provide a detailed description on the microsurgical anatomic features and some landmarks to its identification. METHODS: A microsurgical anatomic dissection of the GSPN was studied in 40 specimens obtained from 20 adult cadaveric heads fixed in formalin. The course of the GSPN and its relationship to neighboring anatomic structures were observed. RESULTS: The GSPN could be divided into four segments: intrapetrosal, suprapetrosal, of foramen lacerum, and of pterygoid canal. About 17.5% (7/40) of GSPNs had communication with the glossopharyngeal nerve (GN). According to communication between the GSPN, internal carotid plexus, and GN, the segment of the foramen lacerum could be divided into five types. The middle meningeal artery and internal maxillary artery were the major blood suppliers of the GSPN. The GSPN usually ran parallel with the lesser petrosal nerve, but sometimes they were at angle to each other. CONCLUSIONS: The relationships between the GSPN and its surrounding structures were studied. The vulnerability of the GSPN is attributed to diverse factors. We confirmed the communication branches between the GSPN and the GN. Our study is important to the understanding of the relationship of the GSPN with adjacent structures and will improve further information during skull base operations.

Denuded human amniotic membrane seeding bone marrow stromal cells as an effective composite matrix stimulates axonal outgrowth of rat neural cortical cells in vitro.

BACKGROUND: Previous studies have shown that axonal outgrowth in the damaged central nervous system is closely related to the local microenvironment. Transplantation of bone marrow stromal cells (BMSC) or BMSC with some biomaterials has been used to treat various central nervous system diseases with some success. In the current study, we investigated if BMSC on denuded human amniotic membrane (DhAM) as a composite matrix could stimulate axonal outgrowth or not. METHOD: After completely removing the cells on the amniotic membrane with a tryptic and mechanical approach, we seeded BMSC on it. The MTS was applied to test the cytotoxicity of DhAM compared with PLGA and PLL. The morphology of the BMSC was observed by light, electronic and laser confocal microscopy. We also used four kinds of substance (PLL, DhAM, BMSC + PLL, BMSC + DhAM) to coculturing with the cortical neurons. Finally, the lengths of axons in each group were studied using the positive axon-specific marker NF-H. FINDINGS: The DhAM was devoid of cellular components and only its intact basement membrane was left. BMSC grew on the substrate and proliferated with a flat to fusiform morphology. In the MTS test, the results indicated that BMSC cultured in DhAM extract had a high survival rate (> 80%). Moreover, the cortical neural axons in the experimental group (BMSC + DhAM) were longer (287.37 +/- 12.72 microm) than in the other groups (P < 0.01). CONCLUSIONS: This study demonstrates that the DhAM was a good carrier to support growth of BMSC and BMSC on DhAM was an effective composite matrix to support the outgrowth of the axons of rat cortical neurons in vitro. Future studies of the use of the composite matrix in disorders are planned.