title: Formation of perineuronal nets in organotypic mouse brain slice cultures is independent of neuronal glutamatergic activity.
abstract: Perineuronal nets (PNs) are a specialized form of the extracellular matrix and cover specific sets of neurons in distinct brain areas. Animal experiments on sensory visual deprivation have demonstrated that the generation of PNs around neurons of the visual cortex is dependent on neuronal activity during the critical period of visual experience. The importance of the activity of specific neurotransmitter systems for PN formation has, however, not yet been demonstrated. Based on the predominantly glutamatergic innervation of the visual cortex we hypothesized that reduced glutamatergic activity impairs the development of PNs. To address this question, genetic mouse models with compromised glutamate release [Munc13-1-knockout (KO) and Munc13-1/2 double-KO (DKO)] and chronic pharmacological treatments interfering with specific steps of glutamatergic transmission were used. Under experimental conditions of glutamatergic hypofunction PN formation was studied in organotypic brain slice cultures with Wisteria floribunda lectin binding and with aggrecan immunohistochemistry. After cultivation for 21 days a regular PN formation was observed in brain slices (i) derived from Munc13-1-KO and Munc13-1/2-DKO mice, (ii) after blockade of metabotropic and ionotropic glutamate receptors with MCPG and kynurenate, and (iii) after suppression of glutamate release by blockade of presynaptic Ca++ channels with riluzole. Nonselective suppression of neuronal activity by blockade of voltage-gated sodium channels with tetrodotoxin clearly inhibited PN formation. These results indicate that neuronal activity is required but that the glutamatergic system is not essential for PN development.
authors.affiliation: Paul Flechsig Institute for Brain Research, Department of Neurochemistry, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Reimers
authors.forename: Maike
authors.initials: M
authors.lastname: Hartlage-Rübsamen
authors.forename: Gert
authors.initials: G
authors.lastname: Brückner
authors.forename: Steffen
authors.initials: S
authors.lastname: Rossner
mesh_terms: D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D019581:Neuropil / Q000378:metabolism / Q000648:ultrastructure; D009924:Organ Culture Techniques; D037121:Plant Lectins; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism; D034781:Receptors, N-Acetylglucosamine; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000235:genetics
chemical_list: D053674:Aggrecans; D015220:Calcium Channels; D018691:Excitatory Amino Acid Antagonists; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D037121:Plant Lectins; D017470:Receptors, Glutamate; D034781:Receptors, N-Acetylglucosamine; D026941:Sodium Channel Blockers; D015222:Sodium Channels; C503321:Unc13a protein, mouse; C485549:Unc13b protein, mouse; C040129:wisteria lectin; D018698:Glutamic Acid