Autonomic Control of Cardiac Arrhythmia

Brack, Kieran E.; Ng, Guseva

doi:10.1007/978-1-4471-5316-0_5

Cited by 1 publication

(1 citation statement)

References 108 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the full extent to which GPs modify cardiac performance and pathology remains unclear, and information pertaining to functional connectivity between plexuses or the extent to which the intrinsic cardiac nervous system can affect regional actions of extrinsic autonomic nerves is needed. More importantly, there are several features of cardiac disease that involve altered autonomic control, including atrial and ventricular arrhythmia (Brack & Ng, 2014), myocardial ischaemia and heart failure (Brack et al 2012). Recently, it has been shown that atrial GP neurons are hypertrophied following heart failure (Singh et al 2013), providing evidence of anatomical changes following cardiac disease.…”

Section: Discussionmentioning

confidence: 99%

The heart's ‘little brain’ controlling cardiac function in the rabbit

Brack

2014

Experimental Physiology

Self Cite

View full text Add to dashboard Cite

New Findings•What is the topic of this review?The topic of the review is the intrinsic cardiac nervous system in the rabbit.•What advances does it highlight?The anatomy of rabbit intrinsic ganglia is similar to that of other species, including humans. Immunohistochemistry confirms the presence of cholinergic and adrenergic neurones, with a striking arrangement of neuronal nitric oxide synthase-positive cell bodies. Activation of atrial ganglia produces effects on local and remote regions.Heart disease is a primary cause of mortality in the developed world, and it is well recognized that neural mechanisms play an important role in many cardiac pathologies. The role of extrinsic autonomic nerves has traditionally attracted the most attention. However, there is a rich intrinsic innervation of the heart, including numerous cardiac ganglia (ganglionic plexuses), that has the potential to affect cardiac function independently as well as to influence the actions of the extrinsic nerves. To investigate this, an isolated, perfused, innervated rabbit Langendorff heart preparation was considered the best option. Although ganglionic plexuses have been well described for several species, there was no full description of the anatomy and histochemistry of rabbit hearts. To this end, rabbit intrinsic ganglia were located using acetylcholinesterase histology (n = 33 hearts). This revealed six generalized ganglionic regions, defined as a left neuronal complex above the left pulmonary vein, a right neuronal complex around the base of right cranial vein, three scattered in the dorsal right atrium and a region containing numerous ventricular ganglia located on the conus arteriosus. Using immunohistochemistry, neurons were found to contain choline acetyltransferase or tyrosine hydroxylase and/or neuronal nitric oxide synthase in differing amounts (choline acetyltransferase > tyrosine hydroxylase > neuronal nitric oxide synthase). The function of rabbit intrinsic ganglia was investigated using a bolus application of nicotine or electrical stimulation at each of the above sites whilst measuring heart rate and atrioventricular conduction. Nicotine applied to different ganglionic plexuses caused a bradycardia, a tachycardia or a mixture of the two, with the right atrial plexus producing the largest chronotropic responses. Electrical stimulation at these sites induced only a bradycardia. Atrioventricular conduction was modestly changed by nicotine, the main response being a prolongation. Electrical stimulation produced significant prolongation of atrioventricular conduction, particularly when the right neuronal complex was stimulated. These studies show that the intrinsic plexuses of the heart are important and could be crucial for understanding impairments of cardiac function. Additionally, they provide a strong basis from which to progress using the isolated, innervated rabbit heart preparation.

show abstract

Section: Discussionmentioning

confidence: 99%