BAGATTO, B; University of Akron: Ontogeny of Cardiovascular Regulation in the Zebrafish (Danio rerio): Plasticity During Environmental Changes

Both sympathetic and parasympathetic components of the autonomic nervous system innervate the myocardium and the pacemaker region of the fish heart. Modulation of the vagal action or tonus on the fish heart is a major regulatory mechanism for altering both heart rate and possibly atrial contraction force. Additionally, sympathetic nerve fibers are present in teleosts and allow a direct, rapid and restricted increase in cardiac activity. Lastly, peripheral resistance may be altered either by vasoconstriction or vasodilatation, thus further modifying cardiac output. The result is a very sensitive control of the cardiovascular system. Although there are studies defining the developmental timing of various pieces of this system, an integrative view of how these pieces function during development has not been studied. Furthermore, the plasticity of this system as a whole under environmentally challenging conditions has yet to be investigated. This study will therefore attempt present an integrative view of the ontogeny of cardiovascular regulation in the zebrafish and measure its developmental plasticity under environmental extremes. To support existing data on the timing of cholinergic and adrenergic receptor activity on the zebrafish heart, known antibodies to these neurotransmitter receptors will be used to confirm their initial presence during development. Once this has been successfully completed on both the heart and the peripheral vasculature, plasticity of this developmental model will be measured under oxygen and temperature extremes. This information will be extremely useful as baseline data when measuring evolutionary change in future generations of zebrafish produced under permanent hypoxia.