Malte Brammerloh1,2, Evgeniya Kirilina1,3, Anneke Alkemade4, Pierre-Louis Bazin1,4, Caroline Jantzen1, Carsten Jäger1,5, Andreas Herrler6, Kerrin J. Pine1, Penny Gowland7, Markus Morawski5, Birte Forstmann4, and Nikolaus Weiskopf1,2
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany, 3Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, Berlin, Germany, 4Integrative Model-based Cognitive Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands, 5Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany, 6Department of Anatomy and Embryology, Maastricht University, Maastricht, Netherlands, 7Sir Peter Mansfield Imaging Center, University of Nottingham, Nottingham, United Kingdom
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany, 3Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, Berlin, Germany, 4Integrative Model-based Cognitive Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands, 5Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany, 6Department of Anatomy and Embryology, Maastricht University, Maastricht, Netherlands, 7Sir Peter Mansfield Imaging Center, University of Nottingham, Nottingham, United Kingdom
The swallow tail sign in T2*-weighted MR images of the substantia nigra does not show a one-to-one correspondence to nigrosome 1, as demonstrated by an overlay of in vivo and postmortem MRI and 3D histology.
Combining in vivo (A) and postmortem (B) MRI with 3D immunohistochemistry (D, E) to study the anatomical underpinning of the swallow tail sign (ST). The ST was segmented (C) as a bright stripe in SN on in vivo MRI (A). N1 was segmented (F) as dark-pigmented areas on grayscale BF images (D) verified by calbindin immunohistochemistry (E). Co-registration (G) of 3D immunohistochemistry, postmortem MRI and in vivo MRI revealed contrast mechanisms of N1 and its relation to the swallow tail sign.
Masks of the ST and N1 for three randomly assigned pairs of in vivo and postmortem datasets (A, B, C) overlaid over BF. In all cases, ST covered a large part of N1. While N1 consistently showed a narrow width, ST was approximately twice as wide as N1. The ST only covered the superior-posterior-lateral portion of N1, while it did not match the ventromedial part of the rostral extent of N1. The anatomical medial (M), lateral (L), superior (S), and inferior (I) directions are illustrated in A.
