title: The elementary events underlying force generation in neuronal lamellipodia.
abstract: We have used optical tweezers to identify the elementary events underlying force generation in neuronal lamellipodia. When an optically trapped bead seals on the lamellipodium membrane, Brownian fluctuations decrease revealing the underlying elementary events. The distribution of bead velocities has long tails with frequent large positive and negative values associated to forward and backward jumps occurring in 0.1-0.2 ms with varying amplitudes up to 20 nm. Jump frequency and amplitude are reduced when actin turnover is slowed down by the addition of 25 nM Jasplakinolide. When myosin II is inhibited by the addition of 20 μM Blebbistatin, jump frequency is reduced but to a lesser extent than by Jasplainolide. These jumps constitute the elementary events underlying force generation.
authors.affiliation: Neurobiology Sector, International School for Advanced Studies (SISSA), IT-34136 Trieste, Italy.
authors.forename: Ladan
authors.initials: L
authors.lastname: Amin
authors.forename: Erika
authors.initials: E
authors.lastname: Ercolini
authors.forename: Rajesh
authors.initials: R
authors.lastname: Shahapure
authors.forename: Giacomo
authors.initials: G
authors.lastname: Bisson
authors.forename: Vincent
authors.initials: V
authors.lastname: Torre
mesh_terms: D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D047630:Depsipeptides / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D024462:Myosin Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D052898:Optical Tweezers; D011554:Pseudopodia / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000199:Actins; D047630:Depsipeptides; D006576:Heterocyclic Compounds, 4 or More Rings; C057531:jasplakinolide; C472645:blebbistatin; D024462:Myosin Type II