The precerebellar linear nucleus in the mouse defined by connections, immunohistochemistry, and gene expression.
The linear nucleus (Li) is a prominent cell group in the caudal hindbrain, which was first described in a study of cerebellar afferents in the rat by [Watson, C.R.R., Switzer, R.C. III, 1978. Trigeminal projections to cerebellar tactile areas in the rat origin mainly from N. interpolaris and N. principalis. Neurosci. Lett. 10, 77-82.]. It was named for its elongated appearance in transverse sections. Since this original description in the rat, reference to the nucleus seems to have been largely absent from experimental studies of mammalian precerebellar nuclei. We therefore set out to define the cytoarchitecture, cerebellar connections, and molecular characteristics of Li in the mouse. In coronal Nissl sections at the level of the rostral inferior olive, it consists of two parallel bands of cells joined at their dorsal apex by a further band of cells, making the shape of the Greek capital letter pi. Our three-dimensional reconstruction demonstrated that the nucleus is continuous with the lateral reticular nucleus (LRt) and that the ambiguus nucleus sits inside the arch of Li. Cerebellar horseradish peroxidase injections confirmed that the cells of Li project to cerebellum. We have shown that Li cells express Atoh1 and Wnt1 lineage markers that are known to label the rhombic lip derived precerebellar nuclei. We have examined the relationship of Li cells to a number of molecular markers, and have found that many of the cells express a nonphosphorylated epitope in neurofilament H (SMI 32), a feature they share with the LRt. The mouse Li therefore appears to be a rostrodorsal extension of the LRt.
Fu
YuHong
Y
Prince of Wales Medical Research Institute, University of New South Wales, NSW 2031, Australia.
Tvrdik
Petr
P
Makki
Nadja
N
Palombi
Olivier
O
Machold
Robert
R
Paxinos
George
G
Watson
Charles
C
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000032:analysis / Q000235:genetics; D015415:Biomarkers / Q000032:analysis; D001931:Brain Mapping; D019070:Cell Lineage / Q000502:physiology; D002531:Cerebellum / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D005697:Galactosides; D015870:Gene Expression; D017930:Genes, Reporter; D006735:Horseradish Peroxidase; D007091:Image Processing, Computer-Assisted; D007211:Indoles; D008526:Medulla Oblongata / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D016900:Neurofilament Proteins / Q000032:analysis / Q000235:genetics; D012154:Reticular Formation / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D012249:Rhombencephalon / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D013194:Staining and Labeling; D051155:Wnt1 Protein / Q000032:analysis / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D005697:Galactosides; D006735:Horseradish Peroxidase; D007211:Indoles; D016900:Neurofilament Proteins; D051155:Wnt1 Protein; C500943:Atoh1 protein, mouse; C495246:Wnt1 protein, mouse; C051774:neurofilament protein H; C044888:5-bromo-4-chloro-3-indolyl beta-galactoside