Sherlock, R.A.Lertsithichai, Somak2025-10-012025-10-011980https://hdl.handle.net/10289/17676A study of the relationship between the cell membrane electrical activity and the observed polar regeneration in anucleate isolated stalk segments of Acetabularia may help answer the question of how a single cell can ‘break symmetry’ and establish a definite polarity. Such studies have been carried out extensively by Novak and Bentrup and their colleagues since 1972, but their results contain unresolved inconsistencies and although their experimental technique overcomes the problems arising from conventional microelectrode techniques, it gives a restricted and electrically perturbative environment for the cell. In an attempt to overcome these limitations the work in this thesis describes the development of a new technique for measuring the electrical activity of the cell membrane with minimum perturbation from the measuring system. In addition it gives more precise and detailed information about the region of action potential initiation and subsequent propagation. The results of measurements using this technique on a variety of intact cells and various cell segments, including anucleate stalk segments are presented and discussed. The results provide strong evidence for the hypothesis that the region of action potential initiation is strongly correlated with the region of current growth. They do not however appear to provide any support for the suggestion of Novak and Bentrup that propagating action potentials are an essential component of the mechanism for ‘symmetry breaking’ in initially unpolarised anucleate stalk segments.enAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.Thesis