Print

TeRiele, Jaclyn Anne

Pharmacology

2008

MS

The sympathetic nervous system is a division of the autonomic nervous system that helps the body maintain homeostasis. Particularly impressive is the sympathetic control over maintenance of blood pressure under an extreme range of environmental conditions. This is achieved by the release of neurotransmitters from the terminal ends of sympathetic neurons that have formed functional synapses on target tissues. During the development of sympathetic innervation, neurons must initially travel from the sympathetic ganglia and weave themselves through a complex series of microenvironments to reach and synapse on the target. Guidance cues, both soluble and contact-dependent, give the neuron constant feedback as to its position and whether it has reached the tissue to be innervated. Artemin is a neurotrophic factor derived from vascular smooth muscle cells that induces neurite outgrowth and could potentially influence sympathetic innervation. The EphA receptors, membrane bound guidance cues, bind EphrinA ligands and are able to collapse growth cones during axon guidance. EphA overexpression models have shown inappropriate innervation as well, although the mechanism of EphAEphrinA function on innervation have not yet been described. In this work, the soluble neurotrophic factor Artemin and the contact-dependent guidance cue family of EphAs/EphrinAs were examined for their effects on sympathetic vascular innervation using both in vitro and in vivo model systems.