{
  "abstract": "Selective vulnerability is a hallmark of Parkinson's disease (PD): post-mortem, dopamine-containing cell loss in the substantia nigra first and most severely affects calbindin-poor compartments termed nigrosomes. Testing this in vivo has been limited by circularity, as MRI studies have delineated nigrosomes from the same disease-related contrast they then measure. Here, we warp histology-derived, calbindin-validated probabilistic masks of nigrosomes 1-5 into a cohort-specific multimodal 7 Tesla quantitative MRI template, providing a degeneration-independent anatomical scaffold, in 28 patients with PD and 28 age- and sex-matched controls. In controls, nigrosomes differ from the surrounding nigral matrix in magnetic susceptibility and R1. PD shifts nigrosomal values upward relative to the matrix in susceptibility, R2*, and R1, concentrated in nigrosomes 1, 2, and 4, whereas whole-nigra analysis shows no group difference. Within the matrix, disease effects are largest caudally and emerge dorsally from the ventral tier, and susceptibility alterations in nigrosomes 1 and 4 track contralateral motor symptoms asymmetry. The multimodal pattern suggests that the detectable signal reflects predominantly secondary, iron-associated glial processes rather than neuronal loss itself. These findings recover the post-mortem spatial pattern of nigral vulnerability in vivo and establish a degeneration-independent framework for subregional nigral imaging in PD.",
  "abstract_shown": true,
  "affiliations": [
    "Norwegian University of Science and Technology; University of Oslo; Ostfold Hospital Trust."
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "name": "R. Li"
    },
    {
      "name": "E. Kirilina"
    },
    {
      "name": "P.-L. Bazin"
    },
    {
      "name": "K. E. Stige"
    },
    {
      "name": "R. Unsgard"
    },
    {
      "name": "M. Brammerloh"
    },
    {
      "name": "I. Gylterud Kvalsgard"
    },
    {
      "name": "A. L. Kristoffersen"
    },
    {
      "name": "E. M. Berntsen"
    },
    {
      "name": "P. E. Goa"
    },
    {
      "name": "P. Damier"
    },
    {
      "name": "C. Tzoulis"
    },
    {
      "affs": [
        0
      ],
      "name": "T. P. Doan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/641qtp3v567ha.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.24.754224",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.24.754224v1.full",
  "id": "641qtp3v567ha",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.24.754224v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "neuroscience"
    ],
    [
      "openalex",
      "2728|Parkinson's Disease Mechanisms and Treatments"
    ]
  ],
  "openalex": "W7214942758",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.24.754224v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/641qtp3v567ha.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:29Z",
      "native_id": "10.64898/2026.09.24.754224",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.24.754224v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:neuroscience",
      "subfield": "neuroscience"
    }
  ],
  "title": "Selective nigrosome vulnerability in Parkinson's disease revealed by histology-anchored ultra-high-field quantitative MRI",
  "title_text": "Selective nigrosome vulnerability in Parkinson's disease revealed by histology-anchored ultra-high-field quantitative MRI",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:29Z",
  "url": "https://research.draconitic.com/paper/641qtp3v567ha",
  "venue": "bioRxiv",
  "versions": []
}