NewPAge

Results: Ciliary beat frequency and calcium
		An expanded view of the top panel (left, below) clearly shows where the ciliary activity (small squares and black arrows) and [Ca²⁺]_i (large white squares) measurements were made as a Ca²⁺ wave passed through each cell. White lines indicate edges of cells.
		An intercellular calcium wave (left), induced by mechanical stimulation (p) of a single cell (far left), propagates through 3 adjacent cells. Numbers in yellow indicate the time each image was captured (in seconds) after stimulation.
		Increase in beat frequency: As the Ca²⁺waves passes through each cell, an increase in beat frequency occurs. The graph (left) shows the intensity waveform (cyan) recorded from each group of cilia. Analysis of the frequency for each beat cycle (red) indicates a sequential increase in frequency. The delay times between cells represent the time taken for the Ca²⁺ wave to reach the base each group of cilia in each cell. A maximal increase in beat frequency occurs within 4 - 6 beat cycles at 22^oC.
		Calcium and beat frequency verse time: In all cells, the beat frequency increases only after the Ca²⁺ has increased at the base of the cilia. It is important to note that the ciliary beat frequency increases did not exactly follow the Ca²⁺ increases. At approximately 250 - 400 nM Ca²⁺, the ciliary activity reached a maximal beat frequency. The beat frequency only began to return to pre-stimulus levels after the Ca²⁺ had been reduced below ~ 350 nM.


		Calcium verses beat frequency: At low or resting Ca²⁺ concentrations the beat frequency is slow with some variability. In fact, Ca²⁺ must increase to ~300 nM before increases in beat frequency occur. Above 400 nM Ca²⁺, the beat frequency does not increase further. This data indicates that increases in ciliary beat frequency have a threshold [Ca²⁺]for activation and maximal frequency response to transient Ca²⁺ increases.