Anomalous Pigmentation in Depigmented Murine Hairs from Neutron Radiation Exposure

Abstract

Abstract Depigmentation in mouse hair is a long-studied consequential effect of radiation exposure. In this study, changes in hair pigmentation in C57BL/6 mice are observed at time points more than 90 days following neutron irradiation. A mixed sex cohort of C57BL/6 mice (N = 40) was exposed to neutron radiation with 18% gamma-ray content at dose rates of 1.5 to 4 Gy/h to get a sham, 1, 2, and 4 Gy dose group. At successive time points following exposure, days 1, 7, 14, 25, 90, 120, and 150, hairs from the mice were plucked and flash-frozen before further analysis. The plucked hair was analyzed by Raman microspectroscopy, using single-point scans for the early time points (days 1–25 postexposure) and hyperspectral images at the later time points (days 90–150 postexposure) to characterize the melanin observed. The chemical changes evident in the Raman data were used for machine learning models of radiation exposure. Raman hyperspectral images reveal anomalous pigment deposits in hairs that appear depigmented to the naked eye. The pigment observed in the day 150 postexposure hyperspectral images is chemically different from both the early time points and age matched control animals. Simply counting the percentage of hairs that are depigmented shows significance at >95% confidence after 90 days. This study indicates impairment of melanocyte function as a deterministic and consequential effect from neutron radiation exposure.

The authors' abstract, as published at the source. Chemical & Biomedical Imaging, 2026 · DOI ↗