title: Cortical cultures coupled to micro-electrode arrays: a novel approach to perform in vitro excitotoxicity testing.
abstract: In vitro neuronal cultures exhibit spontaneous electrophysiological activity that can be modulated by chemical stimulation and can be monitored over time by using Micro-Electrode Arrays (MEAs), devices composed by a glass substrate and metal electrodes. Dissociated networks respond to transmitters, their blockers and many other pharmacological substances, including neurotoxic compounds. In this paper we present results related to the effects, both acute (i.e. 1 hour after the treatment) and chronic (3 days after the treatment), of increasing glutamatergic transmission induced by the application of rising concentrations of glutamate and its agonists (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid - AMPA, N-methyl-D-aspartate - NMDA and AMPA together with cyclothiazide - CTZ). Increase of available glutamate was obtained in two ways: 1) by direct application of exogenous glutamate and 2) by inhibiting the clearance of the endogenously released glutamate through DL-threo-β-benzyloxyaspartate (TBOA). Our findings show that fine modulations (i.e. low concentrations of drug) of the excitatory synaptic transmission are reflected in the electrophysiological activation of the network, while intervention leading to excessive direct stimulation of glutamatergic pathways (i.e. medium and high concentrations of drug) results in the abolishment of the electrophysiological activity and eventually cell death. The results obtained by means of the MEA recordings have been compared to the analysis of cell viability to confirm the excitotoxic effect of the applied drug. In conclusion, our study demonstrates that MEA-coupled cortical networks are very sensitive to pharmacological manipulation of the excitatory ionotropic glutamatergic transmission and might provide sensitive endpoints to detect acute and chronic neurotoxic effects of chemicals and drugs for predictive toxicity testing.
authors.affiliation: Department of Neuroscience and Brain Technologies, Italian Institute of Technology, Genova, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Frega
authors.forename: Valentina
authors.initials: V
authors.lastname: Pasquale
authors.forename: Mariateresa
authors.initials: M
authors.lastname: Tedesco
authors.forename: Manuela
authors.initials: M
authors.lastname: Marcoli
authors.forename: Andrea
authors.initials: A
authors.lastname: Contestabile
authors.forename: Marina
authors.initials: M
authors.lastname: Nanni
authors.forename: Laura
authors.initials: L
authors.lastname: Bonzano
authors.forename: Guido
authors.initials: G
authors.lastname: Maura
authors.forename: Michela
authors.initials: M
authors.lastname: Chiappalone
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D005260:Female; D008839:Microelectrodes / Q000592:standards*; D020258:Neurotoxicity Syndromes / Q000175:diagnosis / Q000503:physiopathology*; D009498:Neurotoxins / Q000633:toxicity*; D011237:Predictive Value of Tests; D011247:Pregnancy; D061251:Primary Cell Culture / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D014116:Toxicology / Q000295:instrumentation / Q000379:methods*
chemical_list: D009498:Neurotoxins