Deposits of iron oxides in the humanglobus pallidus

Abstract

Samples taken from the human brain (Globus Pallidus) have been investigated by physical techniques such as light microscopy, scanning electron microscopy, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. SEM-EDX/TEM investigation reveals multielemental composition of hematite and magnetite nanocrystals with sizes ranging from 40 nm to 100 nm and hematite microcrystals from 3 μm to 7 μm. Room temperature Mössbauer spectra show quadrupole doublets assigning to hematite and ferrihydrite. SQUID measurements of temperature dependence of the mass magnetic susceptibility between T = 2 – 300 K at DC field B0 = 0.1 T, the field dependence of the mass magnetization taken at the fixed temperature T0 = 2.0 and 4.6 K and the zero-field cooled and field cooled magnetization experiments (ZFCM/FCM) confirm a presence of ferrimagnetic phases such as maghemite and/or magnetite with hysteresis loops surviving until the room temperature. Differences between these measurements from the point of view of iron oxides detected can indicate important processes in human brain and interactions between ferritin as a physiological source of iron and surrounding environment.

Variation in the concentration and regional distribution of magnetic nanoparticles in human brains, with and without Alzheimer’s disease, from the UK

“…Discrete nanoparticles of the mixed Fe 2+ /Fe 3+ iron oxide, magnetite, and maghemitised magnetite have been found in senile plaques e.g. 26 and within the frontal cortex 21 , globus pallidus 56 , temporal lobe 49 , superior temporal gyrus 51 , brainstem 31 , 47 , cerebellum 31 , and hippocampus 57 of the human brain, but any relationship between these ferrimagnets and NDD is as yet poorly understood. Using SQUID magnetometry on fresh-frozen human tissue samples, we find a heterogenous distribution of magnetite/maghemite across the brain regions sampled from AD and control cases from northern England.…”