dc.contributor.author | Stoyek, Matthew | |
dc.date.accessioned | 2017-09-15T15:18:20Z | |
dc.date.available | 2017-09-15T15:18:20Z | |
dc.date.issued | 2017-09-15T15:18:20Z | |
dc.identifier.uri | http://hdl.handle.net/10222/73310 | |
dc.description.abstract | In the vertebrate heart the intracardiac nervous system is a common pathway for
autonomic control of cardiac output, comprising a population of intracardiac neurons in
ganglia embedded within nerve plexi. These neural elements modulate the activity of
effectors within the heart to adjust cardiac output, maintaining optimal perfusion of the
body tissues under a wide range of metabolic activities. Investigation of the specific
functional roles of subpopulations of intracardiac neurons within the circuitry mediating
cardiac control in vertebrates has been hampered by a lack of knowledge about the
detailed anatomical organization of the intracardiac nervous system. This work has
revealed within the zebrafish intracardiac nervous system a complex neuroanatomy in
which extrinsic innervation reached all regions of the heart; populations of intracardiac
neurons were present at the sinoatrial and atrioventricular junctions, and adrenergic,
cholinergic, nitrergic and peptidergic neurotransmitter phenotypes were expressed.
Stimulation of individual extrinsic cardiac nerves and application of cholinergic and
adrenergic agents showed that the zebrafish heart contains all the classic vertebrate
hallmarks of cardiac control, establishing this preparation as a viable model for studies of
integrative autonomic control of cardiac function. Disruption of electrical activity within
the sinoatrial region during periods of simulated extrinsic input to the heart illustrated the
complex neural mechanisms involved in rate control. In addition, it was found, using
detection of activity-dependent markers, that distinct populations of intracardiac neurons
were activated during vagal stimulation. This represents the first use of these markers in
the heart, establishing a new method to investigate cardiac function. Further, the use of
the isolated zebrafish heart for studies of clinically relevant issues was validated. These
studies focused on pathways that may be responsible for cardiac dysfunction known to
occur in those on serontonergic anti-depressants as well as in patients during clinical
anesthesia. The results of this work offer a new model for studies of the direct and
neurally mediated pathways involved in heart rate regulation. Overall, the results from
these studies contribute significant advances to the establishment of the zebrafish as a
new model for studies of integrative autonomic cardiac control. | en_US |
dc.language.iso | en | en_US |
dc.subject | cardiovascular | en_US |
dc.subject | autonomic nervous system | en_US |
dc.subject | Zebrafish | |
dc.title | Autonomic innervation and control of chronotropy in the zebrafish heart | en_US |
dc.date.defence | 2016-08-11 | |
dc.contributor.department | Department of Medical Neuroscience | en_US |
dc.contributor.degree | Doctor of Philosophy | en_US |
dc.contributor.external-examiner | Dr. Glen Tibbits | en_US |
dc.contributor.graduate-coordinator | Dr. William Baldridge | en_US |
dc.contributor.thesis-reader | Dr. Robert Rose | en_US |
dc.contributor.thesis-reader | Dr. Kazue Semba | en_US |
dc.contributor.thesis-supervisor | Dr. Frank Smith | en_US |
dc.contributor.thesis-supervisor | Dr. Roger Croll | en_US |
dc.contributor.ethics-approval | Received | en_US |
dc.contributor.manuscripts | Yes | en_US |
dc.contributor.copyright-release | Yes | en_US |