Media type: E-Article Title: Expression of glutamate receptor subtypes in the spinal cord of control and mnd mice, a model of motor neuron disorder Contributor: Mennini, Tiziana; Bigini, Paolo; Ravizza, Teresa; Vezzani, Annamaria; Calvaresi, Novella; Tortarolo, Massimo; Bendotti, Caterina imprint: Wiley, 2002 Published in: Journal of Neuroscience Research Language: English DOI: 10.1002/jnr.10420 ISSN: 0360-4012; 1097-4547 Keywords: Cellular and Molecular Neuroscience Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>We studied the expression and distribution of glutamate receptor subtypes in the spinal cord of <jats:italic>mnd</jats:italic> mice, a model of motor neuron disorders and neuronal ceroid lipofuscinosis, and control mice using immunocytochemistry and in situ hybridization. The constitutive subunit of the NMDA ionotropic glutamate receptor, NMDAR1, was expressed in all neurons of the grey matter and was not modified in the spinal cord of <jats:italic>mnd</jats:italic> mice in either its normal or phosphorylated form. The immunoreactivity of GluR2, but not its mRNA, was increased mainly in the substantia gelatinosa both in presymptomatic and in 8‐month‐old symptomatic mice, suggesting compensatory changes aimed at reducing the Ca<jats:sup>2+</jats:sup> permeability of the receptor channel. In spinal cord of <jats:italic>mnd</jats:italic> mice, mRNA, and protein levels of GluR3 were low only at the symptomatic stage, possibly as a consequence of motor neuron dysfunction. This was not due to motoneuron degeneration, because the number of choline acetyltransferase (ChAT) immunopositive lumbar motor neurons and the ChAT activity in the spinal cord and hind leg muscles of symptomatic <jats:italic>mnd</jats:italic> mice were no different from control mice. GluR4 mRNA was increased throughout the grey matter, presumably in relation to the marked microglia activation reported in the grey matter of the lumbar spinal cord in <jats:italic>mnd</jats:italic> mice. These changes in ionotropic glutamate receptors may alter glutamatergic neurotransmission and play some role in the pathology of <jats:italic>mnd</jats:italic> mice. © 2002 Wiley‐Liss, Inc.</jats:p>