Zebrafish hearts – basic physiology and role of adrenergic stimulation

Zebrafish have risen to prominence as a model organism for understanding complex biological phenomena like the cardiovascular system. Because zebrafish are genetically accessible vertebrates with a optically clear embryo, they are very popular for investigating genetic control of cardiac development. Despite this, almost nothing is known about the physiology of the zebrafish cardiac myocytes.
Stimulation of cardiac β adrenergic receptors (βARs) results in increased cardiac function in mammals but very little is known of βAR signalling in the zebrafish heart. This is becoming increasingly problematic as fish are a growing model for mammalian cardiac studies. This studentship is aimed at investigating, the physiology of zebrafish cardiac myocytes with a particular emphasis on β adrenergic stimulation.
The student will isolate cardiac myocytes from adult fish. They will then characterize their physiology using electrophysiology, video imaging and epi-florescent ion imaging and force measuremtns. All of the major ion pathways that are involved cellular Ca flux and myocyte excitation will be investigated using standard electrophysiological techniques. Video imaging via an edge-detection system will be combined with field stimulation to assess the contractile properties of the myocytes in response to known agonists and antagonists (i.e. adrenaline, adrenoreceptor inhibitors). This will be done at different stimulation frequencies to further characterise the contractile scope of these cells. The student will also use the calcium indicator dye Fura-2 to measure intracellular calcium transients in response to changing stimulation and agonists and antagonists. These will be the first studies to investigate the physiology of cardiac myocytes from the zebrafish. The possibility exists to extend these studies to mutant zebrafish lines.