Naslov
"Leaky myelin" model of myelinated axon signal transmission

Autori
Pađen A.L ; Hashiguchi, T.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Periodicum Biologorum 99 (1997), suppl. 1 / Vitale, Branko - Zagreb : Hrvatsko prirodoslovno društvo, 1997, 129-129

Skup
2nd Croatian Congress of Pharmacology with International Paricipation

Mjesto i datum
Rijeka, Hrvatska, 09.09.1997. - 13.09.1997

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
myelinated axons

Sažetak
Recent experimental data on myelinated axons indicate that the classical model of saltatory conduction (Huxley & Staempfli, 1949) requires modification. We have used mathematical model to simulate eletrophysiological characteristics of large myelinated axons (long charging and discharing processes of the electrotonic potentials, ETPs) obtained by intra-axonal recordins from amphibian and mammalian myelinated axons. The simulation program incorporates parameters of conductances (such as inward rectifier and fast and slow K+ con ductances) based on experimental data and expressed in Hodgking-Huxley equations. it also incorporates all known sections of myelinated axons (nodal, internodal, myelin, unmyelinated sections, definition for perinodal shunt, serial and parallel internodal resistances) and their measured or estimated properties. In order to reproduce ETPs the myelin leakage conductanse and the ionic conductance of internodal membrane are found to be the crucial factors. In contrast to the classical estimate of myelin as an insulator (specific myelin conductance of 1.5 mS/cm2 a much larger value of 80 mS/cm2 is required (leaky myelin", LM). The likely pathways for this conductance are Schmidt-Lantermann incisures or paranodal openings. The conductance of the internodal axolemma requires values that are <0.1% of the measured conductance of the node of Ranvier. The LM model supports the notion that the ion conductances of inernodal axolemma (primarily a variety of K+ conductances) also contribute to and can modulate signal conduction in myelinated axons

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA