| Intracellular
Ca2+
Waves and beat frequency |
|
An expanded view (right) of the top panel (below) to
show the three locations where ciliary beat frequency (small squares,
arrows) and Ca2+ (large squares) were measured in a single
cell. |
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|
An
Intracellular Ca2+ Wave
The sequential elevation of Ca2+ across an individual
cell is called an intracellular wave. The intracellular wave (left) is
initiated at the lower left and propagates towards the right with a
distinct wave front. This intracellular Ca2+ wave was initiated
by the communication of an intercellular wave from a distal mechanically
stimulated cell. Yellow numbers indicate the time (in seconds) at
which the image was captured after stimulation. Experiment was performed
at 37oC |
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| The above graph
plots the intensity waveform (cyan), the ciliary beat frequency
(red) and
the [Ca2+]i (green) with respect to time for each of the
three points indicated above as the intracellular wave passes across the
cell. As the Ca2+ wave passes there is a sequential increase in
beat frequency. This indicates the Ca2+ is acting locally,
perhaps at the ciliary base, to influence beat frequency. The Ca2+
increases before ciliary beat frequency and the increase in frequency
occurs within 4 - 8 cycles. The overall frequencies and response times are
faster because the experiment is conducted at 37o C. A maximal
beat frequency is also reached. |
