# Human brain ferritin studied by muon Spin Rotation: a pilot study

## TL;DR

This pilot study uses Muon Spin Rotation to compare the magnetic properties of brain ferritin proteins from an Alzheimer's patient and a healthy individual, revealing differences in mineral composition and magnetic behavior.

## Contribution

It introduces a novel application of Muon Spin Rotation to study brain ferritin and develops a model based on Néel superparamagnetism for interpreting spin relaxation data.

## Key findings

- Healthy ferritins contain ferrihydrite-like minerals.
- AD ferritins show crystalline phases possibly magnetite or maghemite.
- Differences suggest altered mineralization in Alzheimer's disease.

## Abstract

Muon Spin Rotation is employed to investigate the spin dynamics of ferritin proteins isolated from the brain of an Alzheimer's disease (AD) patient and of a healthy control, using a sample of horse-spleen ferritin as a reference. A model based on the N\'eel theory of superparamagnetism is developed in order to interpret the spin relaxation rate of the muons stopped by the core of the protein. Using this model, our preliminary observations show that ferritins from the healthy control are filled with a mineral compatible with ferrihydrite, while ferritins from the AD patient contain a crystalline phase with a larger magnetocrystalline anisotropy, possibly compatible with magnetite or maghemite.