IMPAIRED INTERNODAL IONIC CONDUCTANCES IN MYELINATED AXONS OF PERIPHERAL NERVES FROM TRANSGENIC MICE WITH DIFFERENT NEUROFILAMENT EXPRESSION (CROSBI ID 478449)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | međunarodna recenzija
Podaci o odgovornosti
Križ, Jasna ; Zhu, Q. ; Meyer, J. ; Simonić, Ante ; Julien, J.P. ; Padjen, Ante L.
engleski
IMPAIRED INTERNODAL IONIC CONDUCTANCES IN MYELINATED AXONS OF PERIPHERAL NERVES FROM TRANSGENIC MICE WITH DIFFERENT NEUROFILAMENT EXPRESSION
Neurofilaments (NFs) are the major cyoskeletal component in large myelinated axons of the peripheral nervous system, and are composed of three prolein subunits, NF-L, NF-M and NF-H, with molecular weight of approximately 70 kD, 145 kD and 200 kD, forming the rope like structures. NFs play a critical role in determining axonal caliber and consequently conduction velocity of large myelinated fibers. The aim of this study was to examine the electrophysiological properties of myelinated axons with altered morphology in transgenic mice with different NF-H expression (NF-H knockout mice and mice overexpressing human NF-H, line 200 mice). Single axons membrane properties were measured on isolated sciatic nerves in vitro using intracellular standard current-clamp technique. Transgenic animals showed several functional deficits in physiological properties. In NF-H knockouts voltage responses revealed increased steady state input resistance (dRss) during depolarization (12.1 ą 1.0 Mohm control vs. 15.5 ą 1.0 Mohm ) and increased peak resistance during evoked hyperpolarization (hRp) (33.5 ą 2.4 Mohm, control vs. 42.6 ą 3.9 Mohm) (control n=28, NF-H-/- n=14). Axons from line 200 transgenic mice showed significant increase in peak (dRp) (14.2 ą 0.95 Mohm, control vs. 23.11 ą 1.7 Mohm) and dRss (12.07 ą 0.82 Mohm vs. 20.44 ą 1.12 Mohm) (control n=28, line 200 n=15) during depolarization associated with impaired inward rectification . Our studies demonstrate that targeted NF-H disruption or human NF-H hyperexpression in transgenic mice affect functional characteristics of large myelinated fibers ( ion channel defects ), suggesting a complex structure/function relationship distinct from previously established structural role of NF.
myelinated axons; transgenic mice; neurofilaments
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Podaci o prilogu
71-x.
1999.
nije evidentirano
objavljeno
Podaci o matičnoj publikaciji
FIFTH IBRO WORLD CONGRESS OF NEUROSCIENCE : Abstracts
Podaci o skupu
FIFTH IBRO WORLD CONGRESS OF NEUROSCIENCE
poster
11.07.1999-15.07.1999
Jeruzalem, Izrael