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Cardiac autonomic innervation of the western pygmy possum (Cercatetus concinnus) and golden bandicoot (Isoodon auratus)

Citation

Zosky, GR and O'Shea, JE, Cardiac autonomic innervation of the western pygmy possum (Cercatetus concinnus) and golden bandicoot (Isoodon auratus), Journal of Comparative Physiology Part B: Biochemical, Systemic, and Environmental Physiology, 187, (1) pp. 203-211. ISSN 0174-1578 (2017) [Refereed Article]

Copyright Statement

Copyright 2016 Springer-Verlag Berlin Heidelberg

DOI: doi:10.1007/s00360-016-1021-1

Abstract

Evidence for a functional ventricular parasympathetic innervation of the mammalian heart between and within taxa remains controversial. We have previously proposed that the presence of a functional parasympathetic innervation of the ventricle was indicative of heterothermy, and is essential for maintaining ventricular stability at low body temperature. However, it is possible that the presence of such an innervation is also representative of the primitive mammalian state. In this study, we aimed to determine whether a functional parasympathetic innervation of the ventricle, that is capable of actively reducing the force of contraction, is present across metatherian mammals. Using in vitro isolated cardiac preparations, we examined evidence for a functional ventricular parasympathetic innervation of the ventricle in two species of metatherian mammal, one heterotherm (Western pygmy possum; Cercatetus concinnus) and one homeotherm (Golden bandicoot; Isoodon auratus), from different families to complement existing data from a heterothermic dasyurid. Both C. concinnus and I. auratus had a potent biphasic response to transmural electrical stimulation in both atrial and ventricular preparations. Both the decrease and increase in the force of contraction in response to stimulation were almost entirely blocked by the cholinergic and adrenergic antagonists, atropine and propranolol, respectively. These observations provide clear evidence for a parasympathetic innervation of the ventricle that is capable of directly influencing the force of contraction across metatherian mammals with different thermoregulatory strategies. While this innervation may facilitate heterothermy, this suggests that the presence of such an innervation pattern is indicative of the primitive mammalian state.

Item Details

Item Type:Refereed Article
Keywords:Parasympathetic, Cardiac innervation, Metatherian, Cercatetus concinnus, Isoodon auratus
Research Division:Biological Sciences
Research Group:Physiology
Research Field:Comparative Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Biological Sciences
Author:Zosky, GR (Associate Professor Graeme Zosky)
ID Code:110319
Year Published:2017 (online first 2016)
Deposited By:Medicine (Discipline)
Deposited On:2016-07-25
Last Modified:2017-11-20
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