Physics Helping to Provide Biological Insight: Combining Optics, Image Processing, Computational Simulation to Aid Biological Understanding

John Girkin (Durham)

The challenges in trying to understand the processes of life are complex and in many areas require a fully multidisciplinary scientific approach in order to make real advances. This involves the development of novel observational methods, subsequent processing of the data, integrating this with biological understanding from other experimental techniques, the subsequent development of a “model” and testing of the model’s predictions. This presentation will look at two areas where this approach has been adopted leading to new insights both biologically and also help to advance optics.

In the first novel optical methods have been developed around a single plane illumination microscope (SPIM) to observe the in vivo development of the lens within an animal’s eye. Based upon some novel optical imaging methods and data processing a new model on the development and movement of cells within the eye lens has been developed.
In the second a miniature optical probe specifically designed to fit inside arteries has made it possible to study a large area of endothelium within intact arteries (0.5 mm in diameter) at normal physiological pressures and with the arteries’ structural integrity maintained. Using external chemical stimulation it has been possible to image calcium signalling under a range of physiologically conditions, including hypertensive pressures.
The resulting complex image patterns have then been analysed using newly developed methods to show repeated cellular signalling patterns that change with agonist concentration and whose signal intensity changes with pressure. Based upon the data analysis a simple mathematical model was subsequently developed and by integrating mathematical simulation of ionic diffusion and the alterations in cell shape as the pressure, and hence vessel dimensions, change a new theory on Mechanotransduction by Geometric Modification is proposed. The presentation will illustrate that such an advance would not have been possible without bringing together optical, biological and simulation expertise.