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Neuronal expression of the proteolipid protein gene in the medulla of the mouse
Author(s) -
Miller Martha J.,
Kangas Cindy D.,
Macklin Wendy B.
Publication year - 2009
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.22121
Subject(s) - biology , proteolipid protein 1 , myelin proteolipid protein , gene expression , microbiology and biotechnology , myelin , medulla oblongata , gene , myelin basic protein , biochemistry , neuroscience , central nervous system
The proteolipid protein (PLP) gene ( Plp ) encodes the major myelin proteins, PLP and DM20. Expression of Plp occurs predominantly in oligodendrocytes, but evidence is accumulating that this gene is also expressed in neurons. In earlier studies, we demonstrated that myelin‐deficient (MD) rats, which carry a mutation in the Plp gene, exhibit lethal hypoxic ventilatory depression. Furthermore, we found that, in the MD rat, PLP accumulated in neuronal cell bodies in the medulla oblongata. In the current study, we sought to determine which neurons expressed the Plp gene in the medulla oblongata and whether Plp gene expression changed in neurons with maturation. A transgenic mouse expressing the Plp promoter driving expression of enhanced green fluorescent protein ( Plp ‐EGFP) was used to identify neurons expressing this gene. Plp expression in neurons was confirmed by immunostaining EGFP‐positive cells for NeuN and by in situ hybridization for PLP mRNA. The numbers of neurons expressing Plp ‐EGFP and their distribution increased between P5 and P10 in the medulla. Immunostaining for surface receptors and classes of neurons expressing Plp ‐EGFP revealed that Plp gene expression in brainstem neurons was restricted to neurons expressing specific ligand‐gated channels and biosynthetic enzymes, including glutamatergic NMDA receptors, GABA A receptors, and ChAT in defined areas of the medulla. Plp gene expression was rarely found in interneurons expressing GABA and was never found in AMPA receptor‐ or tyrosine hydroxylase‐expressing neurons. Thus, Plp expression in the mouse caudal medulla was found to be developmentally regulated and restricted to specific groups of neurons. © 2009 Wiley‐Liss, Inc.