AJP - Regulatory, Integrative and Comparative Physiology, Vol 246, Issue 6 847-R853, Copyright © 1984 by American Physiological Society
What is a biological oscillator?
W. O. Friesen and G. D. Block
Biological oscillators are amenable to qualitative analysis even before
they have been described exhaustively in quantitative terms. Qualitative
analysis can identify the elements essential for generating the
oscillations and can enhance our understanding of underlying oscillator
mechanisms. Two essential elements of a biological oscillator are 1) an
inhibitory feedback loop, which includes one or more oscillating variables,
and 2) a source of delay in this feedback loop, which allows an oscillating
variable to overshoot a steady-state value before the feedback inhibition
is fully effective. The analysis of the patterns of interactions and delays
observed in biological oscillators is simplified by the translation of
variables, interactions, and delays into schematic representations. To
illustrate how such translations can be implemented, three biological
oscillators are described schematically: 1) the glycolytic oscillator, 2)
the bursting of the molluscan neuron, R15, and 3) the oscillations
underlying smooth muscle contractions.
