Stretch-activated cation channels of leech neurons: characterization and role in neurite outgrowth
Authors: Calabrese, B.; Manzi, S.; Pellegrini, M.; Pellegrino, M.
Autors Affiliation: Dipartimento di Fisiologia e Biochimica \”G. Moruzzi\”, Universita\’ di Pisa, Via S. Zeno 31, 56127, Pisa, Italy; Scuola Normale Superiore, piazza Cavalieri 7, 56126, Pisa, Italy.
Abstract: The goal of this study was to characterize the stretch-activated ion channels (SACs) of adult identified neurons of the leech Hirudo medicinalis and to test the role of SACs in neurite outgrowth of isolated cells. Using cell-attached patch recording, we established that SACs are densely distributed in the growth cone membrane of cultured neurons. In excised patches, we found that these channels are permeable to Ca(2+), as well as to monovalent cations. The channels are blocked by the extracellular application of gadolinium (Gd(3+)), amiloride and gentamicin. Amiloride and gentamicin, respectively, induce a partial and complete voltage-dependent block. Time-lapse video recordings of neurite outgrowth from single cultured neurons were used to study the effects of blocking SACs with gentamicin. Within 20 h of plating in the presence of the aminoglycoside, the total length of neuronal arborization was significantly greater than that measured in its absence. The amount of assembled axon per unitary surface area remained constant over 40 h and did not differ significantly with or without gentamicin. Our findings show that SACs of leech neurons admit Ca(2+), are densely distributed in the growth cone membrane and exhibit typical pharmacological features of mechanotransducer ion channels. In addition, our data suggest that these cation channels participate in the early interaction between growing neurites and culture substrate.
Journal/Review: EUROPEAN JOURNAL OF NEUROSCIENCE
Volume: 11 (7) Pages from: 2275 to: 2284
KeyWords: cultured neurons; gentamicin; growth cone; leech; stretch-activated channelsDOI: 10.1046/j.1460-9568.1999.00648.xCitations: 16data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-01-16References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here