carbocyanines and cresyl-violet

With the latest development of Surface Enhanced Raman Scattering (SERS) nanoparticles, Raman spectroscopy now can be extended to bioimaging and biosensing. In this study, we demonstrate the ability of Raman spectroscopy to separate multiple spectral fingerprints using Raman nanotags. A machine learning method is proposed to estimate the mixing ratios of sources from mixture signals. It decomposes the mixture signals into components for both best representation and most relating to mixing ratios. Then regression coefficients are calculated for the prediction. The robustness of the method was compared with least squares and weighted least squares methods.

Topics: Artificial Intelligence; Benzoxazines; Carbocyanines; Coloring Agents; Least-Squares Analysis; Nanoparticles; Regression Analysis; Spectrum Analysis, Raman; Surface Properties

Fiber tract lesions in the central nervous system (CNS) often induce delayed retrograde neuronal degeneration, a phenomenon that represents an important therapeutic challenge in clinical neurotraumatology. In the present study, we report an in vivo trauma model of graded axonal lesion of CNS neurons. Controlled by a newtonmeter device, we induced retrograde degeneration of adult rat retinal ganglion cells (RGCs) by graded crush of the optic nerve. The extent of secondary RGC death increased linearly with the applied crush force. Moreover, visually evoked potentials were used to characterize the consequences of controlled optic nerve lesion on the functional integrity of the visual projection. The presented model of fiber tract lesion closely resembles the clinical conditions of traumatic brain injury and could prove useful to screen for neuroprotective drugs based on both a morphological and functional read-out.

Topics: Animals; Benzoxazines; Brain Injuries; Carbocyanines; Disease Models, Animal; Evoked Potentials, Visual; Female; Fluorescent Dyes; Nerve Crush; Neural Conduction; Neural Pathways; Neuroprotective Agents; Optic Nerve; Optic Nerve Injuries; Oxazines; Rats; Reaction Time; Retinal Ganglion Cells; Retrograde Degeneration

Specialization of the ganglion cell layer (GCL) was studied by Nissl-staining and axonal tract-tracing methods in chicks and chick embryos. The changes in the retinal area and the cell number in the GCL produced a disparity in the cell density that occurred through the two different processes, cell generation (before embryonic days 10-14, E10-14) and cell loss (after E10-14). One high-density area was found in the retinal fundus on E8 (presumptive central area, pCA) and its density decreased toward the peripheral retina. Another high-density area was found in the dorsal retina on E11 (presumptive dorsal area, pDA). Cell densities of the pCA and the pDA on E11 decreased gradually to 25-30% by P1, and after that they further decreased to 40-60% by P30. The pCA was still identified on P30, but the pDA became very obscure by this age. In contrast, ganglion cell sizes increased 5-7 times in the pCA and pDA from E8 to P30, and increased 12 times in the temporal periphery. The present study suggests that the center-peripheral gradient of cell density results from lager scale of cell genesis in the pCA, but not from lager scale of cell loss in the peripheral retina. However, obscuration of the pDA results from equalization of cell density in cellular degeneration processes.

Topics: Animals; Benzoxazines; Carbocyanines; Chick Embryo; Chickens; Coloring Agents; Horseradish Peroxidase; Image Processing, Computer-Assisted; Oxazines; Retinal Ganglion Cells