Cytoarchitecture of the Spinal Cord of the Postnatal (P4) Mouse

Abstract

Interpretation of the new wealth of gene expression and molecular mechanisms in the developing mouse spinal cord requires an accurate anatomical base on which data can be mapped. Therefore, we have assembled a spinal cord atlas of the P4 mouse to facilitate direct comparison with the adult specimens and to contribute to studies of the development of the mouse spinal cord. This study presents the anatomy of the spinal cord of the P4 C57Bl/6J mouse using Nissl and acetyl cholinesterase-stained sections. It includes a detailed map of the laminar organization of selected spinal cord segments and a description of named cell groups of the spinal cord such as the central cervical (CeCv), lateral spinal nucleus, lateral cervical, and dorsal nuclei. The motor neuron groups have also been identified according to the muscle groups they are likely Abbreviations used: 1Sp ¼ lamina 1 of the spinal gray; 2Sp ¼ lamina 2 of the spinal gray; 2SpI ¼ lamina 2 of the spinal gray, inner part; 2Sp ¼ lamina 2 of the spinal gray, outer part; 3Sp ¼ lamina 3 of the spinal gray; 4Sp ¼ lamina 4 of the spinal gray; 5Sp ¼ lamina 5 of the spinal gray; 5SpL ¼ lamina 5 of the spinal gray, lateral part; 5SpM ¼ lamina 5 of the spinal gray, medial part; 6Sp ¼lamina 6 of the spinal gray; 6SpL ¼ lamina 6 of the spinal gray, lateral part; 6SpM ¼ lamina 6 of the spinal gray, medial part; 7Sp ¼ lamina 7 of the spinal gray; 8Sp ¼ lamina 8 of the spinal gray; 9Sp ¼ lamina 9 of the spinal gray; 10Sp ¼ lamina 10 of the spinal gray; Ad9 ¼ adductor motor neurons of lamina 9, asp, anterior spinal artery; Ax9 ¼ axial muscle motor neurons of lamina 9; Bi9 ¼ biceps motor neurons of lamina 9; CC ¼ central canal; CeCv ¼ central cervical nucleus; CEx9 ¼ crural extensor motor neurons of lamina 9; CFl9 ¼ crural flexor motor neurons of lamina 9; Cr9 ¼ cremaster motor neurons of lamina 9; cu ¼ cuneate fasciculus; D ¼ dorsal nucleus (Clarke); dcs ¼ dorsal corticospinal tract; De9 ¼ deltoid motor neurons of lamina 9; df ¼ dorsal funiculus; dl ¼ dorsolateral fasciculus (Lissauer); dr ¼ dorsal root; ExA9 ¼ external anal sphincter motor neurons of lamina 9; ExU9 ¼ external urethral sphincter motor neurons of lamina 9; FEx9 ¼ forearm extensor motor neurons of lamina 9; FFl9 ¼ forearm flexor motor neurons of lamina 9; Gl9 ¼ gluteal motor neurons of lamina 9; gr ¼ gracile fasciculus; Hm9 ¼ hamstring motor neurons of lamina 9; IB ¼ internal basilar nucleus; ICl ¼ intercalated nucleus; IClPe ¼ intercalated nucleus, paraependymal part; ICo9 ¼ intercostal muscle motor neurons of lamina 9; IH9 ¼ infrahyoid muscle motor neurons of lamina 9; IML ¼ intermediolateral column; IMM ¼ intermediomedial column; LatC ¼ lateral cervical nucleus; LD9 ¼ latissimus dorsi motor neurons of lamina 9; LDCom ¼ lumbar dorsal commissural nucleus; lf ¼ lateral funiculus; LPrCb ¼ lumbar precerebellar nucleus, LS9 ¼ levator scapulae motor neurons of lamina 9; LSp ¼ lateral spinal nucleus; Man9 ¼ manus motor neurons of lamina 9; Pec9 ¼ pectoral muscle motor neurons of lamina 9; Pes9 ¼ pes motor neuro...

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