Immunochemical changes of calbindin, calretinin and SMI32 in ischemic retinas induced by increase of intraocular pressure and by middle cerebral artery occlusion / 대한해부학회지

The reaction of neuroactive substances to ischemic conditions in the rat retina evoked by different methods was immunochemically evaluated in adult Sprague-Dawley rats. Ocular ischemic conditions were unilaterally produced by elevating intraocular pressure (EIOP) or by middle cerebral artery occlusion (MCAO). Two EF-hand calcium binding proteins, calbindin D28K (CB) and calretinin (CR), in the normal retina showed similar immunolocalization, such as the amacrine and displaced amacrine cells, the ganglion cells, and their processes, particularly CB in horizontal cells. CB immunoreactive neurons in the ganglion cell layer in both types of ischemic retinas were more reduced in number than CR neurons compared to those in a normal retina. The CB protein level in both ischemic retinas was reduced to 60-80% of normal. The CR protein level in MCAO retinas was reduced to about 80% of normal but increased gradually to the normal value, whereas that in the EIOP showed a gradual reduction and a slight recovery. SMI32 immunoreactivity, which detects a dephosphorylated epitope of neurofilaments-M and -H, appeared in the axon bundles of ganglion cells in the innermost nerve fiber layer of normal retinas. The reactivity in the nerve fiber bundles appeared to only increase slightly in EIOP retinas, whereas a moderate increase occurred in MCAO retinas. The SMI32 protein level in MCAO retinas showed a gradual increasing tendency, whereas that in the EIOP showed a slight fluctuation. Interestingly, the MCAO retinas showed additional SMI32 immunoreactivity in the cell soma of presumed ganglion cells, whereas that of EIOP appeared in the Muller proximal radial fibers. Glial fibrillary acidic protein (GFAP) immunoreactivity appeared in the astrocytes located in the nerve fiber layer of normal retinas. Additional GFAP immunoreactivity appeared in the Muller glial fibers deep in EIOP retinas and at the proximal end in MCAO retinas. These findings suggest that the neurons in the ganglion cell layer undergo degenerative changes in response to ischemia, although EIOP retinas represented a remarkable Muller glial reaction, whereas MCAO retinas had only a small-scaled axonal transport disturbance.

Expression of SMI-32 in neocortex of cortical dysplasia model rats / 重庆医科大学学报

Objective:To investigate the expression of SMI-32 in neocortex of Cortical dysplasia(CD)model Rats. Methods:Pregnant rats were injected carmustine (1,3-bis-chloroethy1–nitrosourea,BCNU) intraperitoneally on embryonic 17thday (E17),cortical histology and immunohistochemistry were examined on the tissue of cerebral cortex of the offsprings at postonatal 28thday(P28). Results:Niss staining showed features of CD in the offsprings,including laminar disorganization, cytomegalic neurons and heterotopic neurons. Immunohistochemistry demonstrated that SMI-32 was expressed poorly in layerⅡ、Ⅴand the majority of them were expressed in layers Ⅳ,Ⅵ of the primary somatosensory and motor cortices with many abnormal neurons,part of them were in clusters,few were expressed in layer Ⅲ. Conclusion:SMI-32 was expressed abnormally in neocortex of CD model rats as one of layer-specific markers of cerebral cortex, and it may be an index of pathologic diagnosis of CD.

Effect of different substrates coated on spinal motor neurons from embryonic rat cultured in vitro / 中国免疫学杂志

Objective:To study the effect of different substrates coated on the cell survival and neurite outgrowth of spinal motor neurons (SMN) from embryonic rat cultured in vitro.Methods:The ventral spinal tissue was isolated from embryonic rats and digested into dissociated cell suspention for culture,then the cells were identified as SMN by immunohistochemistry stain.Poly-L-lysine(PLL) was dissolved into distilled water,phosphate-buffered saline solution,boric acid at 0.1 and 0.01 mol/L concentration respectively.The different substrates include PLL,collagen Ⅰ,laminin and PLL combined with laminin.Distilled water was used as control.The neuron survival numbers and the mean length of the neurites were measured and compared.Results:The cells on the PLL dissolved into boric acid at 0.01 mol/L concentration survived well.The SMNs grown on the PLL combined with laminin were in dispersed disitribution with high survival rate.Conclusion:PLL combined with laminin is the best for the study of the motor neuron including both soma and neurite.