INVESTIGADORES
PONCE DAWSON Silvina Martha
artículos
Título:
Crisis on skid-row
Autor/es:
JOHN E. PEARSON; SILVINA PONCE-DAWSON
Revista:
PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS
Referencias:
Año: 1998 vol. 257 p. 141 - 148
ISSN:
0378-4371
Resumen:
We consider an idealized model of Ca
release from internal stores in living cells (the skid row relay) in
order to explore the effect of the distribution of release sites. The
skid row relay is an all or none release model in which a fixed amount
of Ca
is released when the cytosolic Ca
density in the vicinity of the release site reaches a threshold.
Depending on the time and space scales the skid row relay can support
traveling waves with a velocity that scales as either
or
(where
is the diffusion coefficient for Ca
). The former scaling holds when the continuum approximation for the
distribution of release sites is valid. The latter holds when the
release sites are sufficiently far apart. We determine an analytic
expression for the velocity of propagating waves in the two regimes. In
the discrete case it can be shown that traveling wave solutions do not
exist if the release sites are too far apart or do not release enough Ca
or if the threshold for release is too high. Well before the traveling
wave ceases to exist, the wave loses stability through period doubling
and crisis.