title: Combined optical tweezers and laser dissector for controlled ablation of functional connections in neural networks.
abstract: Regeneration of functional connectivity within a neural network after different degrees of lesion is of utmost clinical importance. To test pharmacological approaches aimed at recovering from a total or partial damage of neuronal connections within a circuit, it is necessary to develop a precise method for controlled ablation of neuronal processes. We combined a UV laser microdissector to ablate neural processes in vitro at single neuron and neural network level with infrared holographic optical tweezers to carry out force spectroscopy measurements. Simultaneous force spectroscopy, down to the sub-pico-Newton range, was performed during laser dissection to quantify the tension release in a partially ablated neurite. Therefore, we could control and measure the damage inflicted to an individual neuronal process. To characterize the effect of the inflicted injury on network level, changes in activity of neural subpopulations were monitored with subcellular resolution and overall network activity with high temporal resolution by concurrent calcium imaging and microelectrode array recording. Neuronal connections have been sequentially ablated and the correlated changes in network activity traced and mapped. With this unique combination of electrophysiological and optical tools, neural activity can be studied and quantified in response to controlled injury at the subcellular, cellular, and network level.
authors.affiliation: Department of Neuroscience and Brain Technologies, Italian Institute of Technology, Via Morego 30, Genoa 16163, Italy. Francesco.difato@iit.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Difato
authors.forename: Marco
authors.initials: M
authors.lastname: Dal Maschio
authors.forename: Emanuele
authors.initials: E
authors.lastname: Marconi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ronzitti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Maccione
authors.forename: Tommasso
authors.initials: T
authors.lastname: Fellin
authors.forename: Luca
authors.initials: L
authors.lastname: Berdondini
authors.forename: Evelina
authors.initials: E
authors.lastname: Chieregatti
authors.forename: Fabio
authors.initials: F
authors.lastname: Benfenati
authors.forename: Axel
authors.initials: A
authors.lastname: Blau
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004210:Dissection / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053685:Laser Therapy / Q000295:instrumentation*; D008866:Microsurgery / Q000295:instrumentation*; D009415:Nerve Net / Q000166:cytology / Q000601:surgery*; D016501:Neurites / Q000648:ultrastructure; D052898:Optical Tweezers; D051381:Rats; D017207:Rats, Sprague-Dawley; D012371:Robotics / Q000295:instrumentation*; D018511:Systems Integration