Expression of AMPA and NMDA receptor subunits in the cervical spinal cord of wobbler mice.
BACKGROUND
The localisation of AMPA and NMDA receptor subunits was studied in a model of degeneration of cervical spinal motoneurons, the wobbler mouse. Cervical regions from early or late symptomatic wobbler mice (4 or 12 weeks of age) were compared to lumbar tracts (unaffected) and to those of healthy mice.


RESULTS
No differences were found in the distribution of AMPA and NMDA receptor subunits at both ages. Western blots analysis showed a trend of reduction in AMPA and NMDA receptor subunits, mainly GluR1 and NR2A, exclusively in the cervical region of late symptomatic mice in the triton-insoluble post-synaptic fraction but not whole homogenates. Colocalisation experiments evidenced the expression of GluR1 and NR2A receptors in activated astrocytes from the cervical spinal cord of wobbler mice, GluR2 did not colocalise with GFAP positive cells. No differences were found in the expression of AMPA and NMDA receptor subunits in the lumbar tract of wobbler mice, where neither motoneuron loss nor reactive gliosis occurs.


CONCLUSIONS
In late symptomatic wobbler mice altered levels of GluR1 and NR2A receptor subunits may be a consequence of motoneuron loss rather than an early feature of motoneuron vulnerability.
Bigini
Paolo
P
Laboratory of Receptor Pharmacology, Department of Biochemistry and Molecular Pharmacology, Mario Negri Institute for Pharmacological Research, Milano, Italy. bigini@marionegri.it
Gardoni
Fabrizio
F
Barbera
Sara
S
Cagnotto
Alfredo
A
Fumagalli
Elena
E
Longhi
Annalisa
A
Corsi
Massimiliano M
MM
Di Luca
Monica
M
Mennini
Tiziana
T
D000818:Animals; D002574:Cervical Vertebrae / Q000378:metabolism; D004195:Disease Models, Animal; D015870:Gene Expression; D051379:Mice; D016472:Motor Neuron Disease / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D014018:Tissue Distribution
D021122:Protein Subunits; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate