Brain ependymal cilia
thesisposted on 15.12.2014, 10:31 by Christopher. O'Callaghan
Densely ciliated ependymal cells line the ventricular surface of the brain, cerebral aqueduct, and the central canal of the spinal cord and beat continuously at up to 40Hz.;Methodologies for the measurement and the containment of ependymal cilia were developed to allow their study in an ex-vivo setting. Three methods were used to measure ciliary beat frequency, the photomultiplier, photodiode and high speed imaging were established and compared.;The method used, to hold ciliated ependymal strips affected ependymal ciliary beat frequency. Tissue held in a microscope cover glass system, or under direct observation of a water immersion lens, showed a beat frequency of half that of cilia observed in an incubation chamber using an inverted microscope. The incubation system, using an inverted microscope, and high speed video system were chosen for the studies in this thesis.;Thes results obtained using this system may be summarised as follows:; there was no change in ciliary length or beat frequency between ependyma from infant and adult Wistar rats. However, ependymal cilia beat twice as fast as respiratory cilia.; a pH of less than 7 was associated with dramatic fall in ciliary beat frequency which was shown to be directly related to changes in intracellular pH.; increasing viscosity decreased ciliary beat frequency, though cilia demonstrated a capability to adapt to an increasing viscous load.; pentobarbitone only slowed cilia at levels which were incompatible with life. Halothane, a volatile anaesthetic, caused significant, but reversible ciliary slowing at concentrations which are used in a clinical setting.; adrenergic agents and forskolin had no effect on ependymal ciliary function.; ethanol and acetaldehyde had no effect on ependymal ciliary beat frequency.; low concentrations of the toxin MAM, thought to be implicated in the development of Parkinsonism, caused ciliary slowing.