Focal injection of Ethidium bromide as a simple model to study cognitive deficit and its improvement

Introduction: Memory and cognitive impairments are some of devastating outcomes of Multiple Sclerosis [MS] plaques in hippocampus, the gray matter part of the brain. The present study aimed to evaluate the intrahippocampal injection of Ethidium Bromide [EB] as a simple and focal model to assess cognition and gray matter demyelination

Methods: Thirty Wistar rats were divided into three groups: control group, which received saline, as solvent of EB, into the hippocampus; and two experimental groups, which received 3 microL of EB into the hippocampus, and then, were evaluated 7 and 28 days after EB injection [n=10 in each group], using a 5-day protocol of Morris Water Maze [MWM] task as well as Transmission Electron Microscopy [TEM] assay

Results: Seven days after EB injection, the behavioral study revealed a significance increase in travelled distance for platform finding in the experimental group compared to the control group. In addition, the nucleus of oligodendrocyte showed the typical clumped chromatin, probably attributed to apoptosis, and the myelin sheaths of some axons were unwrapped and disintegrated. Twenty-eight days after EB injection, the traveled distance and the time spent in target quadrant significantly decreased and increased, respectively in experimental groups compared to the control group. Also, TEM micrographs revealed a thin layer of remyelination around the axons in 28 days lesion group

Discussion: While intracerebral or intraventricular injection of EB is disseminated in different parts of the brain and can affect the other motor and sensory systems, this model is confined locally and facilitates behavioral study. Also, this project could show improvement of memory function subsequent to the physiological repair of the gray matter of the hippocampus

Tissue remodeling investigation in varicose veins

Although the etiology of varicose veins remains unknown, recent studies have focused on endothelial cell integrity and function because the endothelium regulates vessel tone and synthesizes many pro- and anti-inflammatory factors. The aim of this study was to investigate the evidence involving the endothelium in the development of varicose vein disease. In addition, tissue remodeling was investigated in varicose veins to determine the expression of different types of collagen. Tissue specimens of superficial varicose veins and control saphenous vein were used for immunohistochemical and transmission electron microscope [TEM]. alpha- smooth muscle actin, and collagen I, III, IV antibodies were applied for immunohistochemical investigation. Findings of this study showed alterations of the intima, such as focal intimal discontinuity and denudation of endothelium; and the media, such as irregular arrangements of smooth muscle cells and collagen fibres in varicose veins. Our findings showed some changes in terms of distribution of types I, III and IV collagen in the intima and media of varicose vein walls compared with controls. These alterations to the media suggest that the pathological abnormality in varicose veins may be due to the loss of muscle tone as a result of the breakup of its regular structure by the collagen fibres. These findings only described some changes in terms of distribution of these types of collagen in the intima and media of varicose vein walls which may result in venous wall dysfunction in varicosis.