Topographic Trace-Elemental Analysis in the Brain of Wistar Rats by X-ray Microfluorescence with Synchrotron Radiation

Abstract

Knowledge about the spatial distribution and the local concentration of trace elements in tissues is of great importance, since trace elements are involved in many biological functions of living organisms. However, there are few methods available to measure the spatial (two (three)-dimensional) elemental distribution in animal brain. X-ray microfluorescence with synchrotron radiation is a multielemental mapping technique, which was used in this work to determine the topographic of iron, zinc and copper in coronal sections of female Wistar rats of different ages. Young (14 days old) and middle-aged (20 months old) rats (n = 8) were analyzed. The measurements were carried out at the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). Two-dimensional scanning was performed in order to study the tendency of elemental concentration variation. The acquisition time for each pixel was 10 s/step and the step size was 300 mm/step in both directions. It was observed that the iron distribution was more conspicuous in the cortical area, thalamus and bellow the thalamus. On the other hand, the zinc distribution was more pronounced in the hippocampus. The iron, copper and zinc levels increased with advancing age. Therefore, this study reinforces the idea that these elements are involved in the chemical mechanisms of the brain that induce some neurological diseases, since they are also present in high levels in specific areas of the brain, such as the hippocampus and the substantia nigra of patients with these disorders.

In vivomonitoring of the transfer kinetics of trace elements in animal brains with hyphenated inductively coupled plasma mass spectrometry techniques

“…According to Jackson et al (2006), the complexity of sample preparation and instrumental techniques, the expense of instrument, and the number of analyte ions that can be determined are the important criteria for selecting a surface analytical technique. Based on literatures reported previously, besides the abovementioned fluorescence microscopic techniques, proton-induced X-ray emission (PIXE) (Thong et al, 1999;Robertson et al, 2002;Augustyniak et al, 2006;Reinert et al, 2007), microprobe synchrotron X-ray fluorescence (ASXRF) (Ide-Ektessabi, Kawakami, & Watt, 2004;Flinn et al, 2005;Serpa et al, 2008), synchrotron X-ray absorption spectroscopy (SXAS) (Collingwood et al, 2005;Mikhaylova et al, 2005), secondary ion mass spectrometry (SIMS) (Burns, 1981;Clerc, Fourre, & Fragu, 1997;Aranyosiova et al, 2008), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) (Feldmann, Kindness, & Ek, 2002;Becker et al, 2005aBecker et al, ,b, 2007aBecker et al, ,b, 2008aJackson et al, 2006;Dobrowolska et al, 2008;Sela et al, 2007;Zoriy et al, 2008) are the most widely applied surface analytical techniques for elemental imaging in brain tissues.…”

Copper chelators promote nonamyloidogenic processing of AβPP via MT1/2/CREB‐dependent signaling pathways in AβPP/PS1 transgenic mice

“…Postmortem studies have shown that copper levels are increased in Aβ plaques in the brains of patients with AD . Furthermore, the content and distribution of copper in the brain changes with aging and neurodegenerative diseases . Recent studies have also demonstrated that abnormal copper homeostasis in the brain is involved in the progression of AD and possibly other neurodegenerative diseases .…”

Age-dependent increase of brain copper levels and expressions of copper regulatory proteins in the subventricular zone and choroid plexus

“…Previous studies from this laboratory have demonstrated that the BBB serves as the major route for the transport of Cu into the brain parenchyma, while the BCB mainly contributes to maintain the Cu homeostasis in the brain by exporting excess Cu from the CSF to the blood (Choi and Zheng, 2009 ; Zheng and Monnot, 2012 ; Fu et al, 2014 ). Once entering the brain, the Cu content and spatial distribution are uneven (Becker et al, 2005 ; Lech and Sadlik, 2007 ; Dobrowolska et al, 2008 ; Davies et al, 2013 , 2014 ; Ramos et al, 2014 ), which also vary among different species (Waggoner et al, 2000 ; Olusola et al, 2004 ; Jackson et al, 2006 ), and change during the development, with age and in neurodegenerative conditions (Palm et al, 1990 ; Tarohda et al, 2004 ; Serpa et al, 2008 ; Wang et al, 2010 ; Ramos et al, 2014 ). Age-related increase in brain Cu content was observed in mouse (Wang et al, 2010 ), rat (Palm et al, 1990 ), and bovine (Zatta et al, 2008 ).…”