Structural reorganization of neurocytes of CA1 field of hippocampus in dynamic after experimental thermal trauma and application of lyophilized xenograft

Abstract

reorganization of animals in dynamics after experimental thermal injury and use of lyophilized xenograft. Materials and Methods. In the experiment on 35 mature white male rats microscopic, electronmicroscopic and morphometric study of animals’ hippocampus were made after severe thermal injury in terms of early necrectomy of affected area and closure by lyophilized xenograft. Experimental animals of the third experimental group were decapitated on the 7th, 14th and 21st days of experiment. Sections of the brain tissue have been taken from the hippocampus area for histological studies, fixed in 96o alcohol and 10 % neutral formalin and embedded in the paraffin blocks. Obtained on microtome sections were stained with hematoxylin and eosin and toluidine blue with Nissl method. Ultrathin sections were contrasted by uranyl acetate and lead citrate according to Reynolds method and were studied in the electron microscope PEM-125K. Morphometric study was performed using system of visual analysis of histological specimens. Results. It has been established that on the 7th day of the experiment with the usage of corrective factor the number of destroyed neurons in CA1 field of hippocampus was less, but still not significant compared to burned untreated animals. Neurocytes were in state of peripheral or segmental tigrolysis, and there was an increase in the square of hypochromic cells nuclei, some of them contained large nucleoli. Microscopically and electronmicroscopically on the 14th and especially on the 21st days of the experiment, there was found a significant improvement of histological condition of neurocytes, numerical density of the nerve cells in the CA1 field of hippocampus was significantly 1.25 times higher, and the number of normochromic cells 5.52 times more than in the animals with burns. Conclusions. Thus, the application of lyophilized xenograft after early necrectomy of burned skin earlier (the 7th day of experiment) after burn injury prevents deep changes of hippocampus CA1 field neurocytes, reduces the number of damaged cells. The positive impact of lyophilized xenograft application is the most expressive at the later stages after burn (the 14th and the 21st days of the experiment). Histologically there is a relative normalization of microscopic and ultrastructural composition of neurocytes, improvement in indices of density and proportion of nerve cells different types in the CA1 field of the hippocampus.

Keywords

• hippocampus
• neurons
• burns
• lyophilized xenografts