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Epilepsy, the third most common neurological disorder, is characterized by recurrent unprovoked seizures. Although the mechanisms of epileptic convulsions have been a subject of intensive investigations for many years in most cases the etiology of the disease is not known [1].Metallic elements participating in the processes like: oxidative stress, excitotoxicity, mitochondrial dysfunction or protein aggregation may lead to the atrophy and death of neurons in case of some neurodegenerative disorders [2][3][4]. Because epileptic seizures induce neurodegeneration in selected areas of brain it is suspected that metals may be involved in the pathogenesis and progress of epilepsy as well [5].Existing evidence suggests that epileptic seizures significantly change metabolism and distribution of trace elements in the nervous tissue [6][7][8]. From the other hand, content of metals determinates susceptibility to convulsions [9].In our experiment we used pilocarpine in order to induce epilepsy in rats. In order to find what elements are involved in the pathogenesis and progress of epileptic convulsions the comparison between pilocarpine treated and control rats was done. The samples of rat brain were cut using a cryomicrotome into 15 µm thick slices. Thin tissue sections were mounted on Ultralene foil and freeze-dried.X-ray fluorescence microscopy was employed for topographic and quantitative analysis of selected metals in the areas of brain tissue involved in epilepsy. The measurements were done on the bending magnet beamline L at HASYLAB. The multilayer monochromator was applied and the primary photon energy was set to 17 keV. The beam was focused with polycapillary optics for a final beam spot dimension of 15 µm x 15 µm. The characteristic X-ray lines were measured using the Vortex SDD detector from SII Nano Technology USA inc. and the time of spectra acquisition was equal to 6 s per pixel. Measurements of NIST standard reference materials (SRM 1833 and SRM 1832) were performed for spectrometer calibration.The elements such us P, S, Cl, K, Ca, Fe, Cu, Zn, Br, Rb and Sr were detected in rat brain sections. For each sample two-dimensional analysis of elemental distribution was performed for the area of hippocampus and brain cortex. The results of such analysis for selected control and epileptic sample were shown in Figures 1 and 2 respectively.For four regions of hippacampus formation (CA1 -Cornu Ammonis, CA3, DG -Dentate Gyrus and H -Hilus) and motor cortex the mean masses per unit area were evaluated. The areas taken into account in calculations were equal to 300 µm per 300 µm. The preliminary results showed that the level of Ca tends to be higher for CA1 region of hippocampus and cortex in case of animals with pilocarpine induced epilepsy. The opposite relation was observed for Zn level in the area of DG.1551

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Amyotrophic Lateral Sclerosis (ALS) is an untreatable, neurodegenerative disease of motor neurons characterized by progressive muscle atrophy, limb paralysis, dysarthria, dysphagia, dyspnae and finally death. Large motor neurons in ventral horns of spinal cord and motor nuclei in brainstem, large pyramidal neurons of motor cortex and/or large myelinated axons of corticospinal tracts are affected. In recent synchrotron Fourier Transform Infrared microspectroscopy (sFTIR) studies of ALS CNS autopsy tissue, we discovered a small deposit of crystalline creatine, which has a crucial role in energy metabolism. We have now examined unfixed, snap frozen, post-autopsy tissue sections of motor cortex, brain stem, spinal cord, hippocampus and substantia nigra from six ALS and three non-degenerated cases with FTIR and micro-X-ray fluorescence (XRF). Heterogeneous pigmented deposits were discovered in spinal cord, brain stem and motor neuron cortex of two ALS cases. The FTIR signature of creatine has been identified in these deposits and in numerous large, non-pigmented deposits in four of the ALS cases. Comparable pigmentation and creatine deposits were not found in controls or in ALS hippocampus and substantia nigra. Ca, K, Fe, Cu and Zn, as determined by XRF, were not correlated with the pigmented deposits; however, there was a higher incidence of hot spots (Ca, Zn, Fe and Cu) in the ALS cases. The identity of the pigmented deposits remains unknown, although the absence of Fe argues against both erythrocytes and neuromelanin. We conclude that elevated creatine deposits may be indicators of dysfunctional oxidative processes in some ALS cases.

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Synchrotron microbeam X‐ray fluorescence (µ‐SXRF) was applied for topographic and quantitative analysis of selected elements in human brain and spinal cord. The main goal of the study is a better understanding of the role of elements, mainly metals, in processes leading to degeneration and atrophy of nerve cells in cases of two neurodegenerative disorders, i.e. Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). The samples were taken during the autopsy from patients deceased with PD, ALS, and from a patient who died due to non‐neurological conditions. In measurements, a 5 × 2 µm2 X‐ray beam was applied for scanning the thin tissue slices. Two‐dimensional maps of elemental distribution were compared with histopathological sections. The results obtained showed that the spatial distribution of selected elements precisely corresponds to the microscopic views of scanned area of tissue. Moreover, differences in accumulation of selected elements in nerve cell bodies and areas representing white matter between patients affected by PD, ALS and the control case were noticed. The present investigation showed that the µ‐SXRF technique is suitable for elemental analysis at the single cell level in applications in neurological research. Copyright © 2003 John Wiley & Sons, Ltd.

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