title: Morphological features and responses to AMPA receptor-mediated excitotoxicity of mouse motor neurons: comparison in purified, mixed anterior horn or motor neuron/glia cocultures.
abstract: Primary motor neuron cultures are widely used as in vitro model to study the early mechanisms involved in the aetiology of amyotrophic lateral sclerosis. In this study, we directly compared the morphological features and the responses to AMPA receptor (AMPAR) activation of mouse spinal cord motor neurons under different culture conditions (OptiPrep-purified, mixed anterior horn or motor neuron/glia cocultures). Motor neurons cocultured with a confluent glial layer had significant improvements in axonal length and in somata perimeter and area, compared both to mixed anterior horn cultures and to purified cultures, suggesting that the presence of more "mature" glial cells was determinant to obtain healthier motor neurons. By immuno-cytochemical assays we found that both in mixed anterior horn cultures and in cocultures, lower AMPA (0.3 microM) or kainate (5 microM) concentrations, but not the higher (1 or 15 microM, respectively), induced classical apoptotic events such as the nuclear fragmentation, the membrane externalization of phosphatidylserine residues and the activation of caspases-9 and -3. The morphological features and the different degenerative pathways induced by AMPAR agonist concentrations suggest that the experimental conditions used for in vitro studies are key factors that should be deeply considered to obtain more valid and reproducible results.
authors.affiliation: Department of Molecular Biochemistry and Pharmacology, Mario Negri Institute for Pharmacological Research, Via La Masa 19, Milan, Italy. depaola@marionegri.it
authors.forename: Massimiliano
authors.initials: M
authors.lastname: De Paola
authors.forename: Valentina
authors.initials: V
authors.lastname: Diana
authors.forename: Paolo
authors.initials: P
authors.lastname: Bigini
authors.forename: Tiziana
authors.initials: T
authors.lastname: Mennini
mesh_terms: D000818:Animals; D017304:Annexin A5; D000870:Anterior Horn Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D016923:Cell Death / Q000502:physiology; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D018920:Coculture Techniques; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018846:Excitatory Amino Acids / Q000633:toxicity*; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009046:Motor Neurons / Q000187:drug effects / Q000473:pathology* / Q000648:ultrastructure; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D018091:Receptors, AMPA / Q000187:drug effects* / Q000378:metabolism; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D017304:Annexin A5; D018690:Excitatory Amino Acid Agonists; D018846:Excitatory Amino Acids; D005456:Fluorescent Dyes; D018091:Receptors, AMPA; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D053148:Caspase 3; D053453:Caspase 9; C104722:glutamate receptor ionotropic, AMPA 2; D007608:Kainic Acid