Porcine intrinsic cardiac ganglia

Abstract

The gross, light, and electron microscopic anatomies of the porcine intrinsic cardiac nervous system were investigated in 26 pigs to facilitate functional studies in this model. Gross anatomy: Numerous ganglia and interconnecting nerves (ganglionated plexuses) were found to be concentrated in epicardial fat in five atrial and six ventricular regions. The five atrial ganglionated plexuses identified were (1) the ventral right atrial, (2) the right vena cava-right atrial, (3) the dorsal atrial, (4) the interatrial septal, and (5) the left superior vena cava-left atrial ones. Six ventricular ganglionated plexuses were identified in close proximity to the (1) roots of the aorta and pulmonary artery (craniomedial), extending along the left main coronary artery to the (2) ventral interventricular and (3) circumflex coronary arteries. (4) A ganglionated plexus was identified around the origin of the dorsal interventricular coronary artery, as well as the (5) right main and (6) right marginal coronary arteries. Isolated neurons were identified scattered throughout the cranial interventricular septum. Microscopic anatomy: Approximately 3,000 neuronal somata were estimated to compose this intrinsic cardiac nervous system. Some ganglia contained more than 100 neurons. Neuronal somata had dimensions of roughly 33.1 (short axis) by 46.3 (long axis) m. Most were multipolar, a small population of unipolar neurons being identified in atrial and ventricular tissues. At the electron microscopic level, asymmetrical axodendritic synapses with small clear, round vesicles were identified, some containing large dense-cored vesicles. In summary, porcine intrinsic cardiac neurons are concentrated in 11 distinct atrial and ventricular ganglionated plexuses. These extensive plexuses, along with fewer scattered neurons, display varied neuronal morphology and synaptology that represent the anatomical substrate for complex information processing within the intrinsic cardiac component of the porcine cardiac neuronal hierarchy. These anatomical data provide a framework for physiological analyses of the porcine intrinsic cardiac nervous system. Anat Rec Part A 271A:249 -258, 2003. Key words: atrial neurons; dendrites; ganglionated plexus; ventricular neuronsIntrinsic cardiac neurons, first identified on the human heart by Scarpa in 1794 (cited by Mitchell et al., 1952), have been described in a variety of mammalian species (Dogiel, 1899;Francillon, 1928;Kuntz, 1934;Davies et al., 1952;King and Coakley, 1958;Robb, 1965;Shvalev and Sosunov, 1985;Gagliardi et al., 1988;Yuan et al., 1994;Armour et al., 1997;Pauza et al., 1997Pauza et al., , 2000. Intrinsic cardiac neurons are concentrated in collections of ganglia and interconnecting nerves that form identifiable ganglionated plexuses within epicardial fat (Gagliardi et al., 1988;Yuan et al., 1994;Armour et al., 1997;Pauza et al., 2000;Pauziene et al., 2000). Although the neurons are typically found in epicardial fat at the base of the atria, in the interatrial septum and on the cranial as...

Long-Term Effects of Ganglionated Plexi Ablation on Electrophysiological Characteristics and Neuron Remodeling in Target Atrial Tissues in a Canine Model

“…21 Numerous studies have observed multiple major and small GPs in the atria of mammalian hearts. 19,[22][23][24] These GPs modulate the interaction and balance between the extrinsic and intrinsic autonomic nervous system and contain efferent cholinergic and adrenergic neurons which influence the atrial myocardium, 25 in terms of action potential duration, AERP, and conduction velocity. In many animal studies, autonomic denervation exhibited short-term efficacy.…”

Location and variability of epicardiac ganglia in human fetuses

“…From a number of neuroanatomically investigated mammalian species it is known that cardiac ganglia are mainly distributed on certain atrial regions around the sinuatrial node, at the roots of the vena cava and pulmonary veins, above and within the interatrial septum, in the proximity of atrioventricular node and, even in the auricular appendages (King and Coakley 1958;Navaratnam 1965;BojsenMoller and Tranum-Jensen 1971;Baptista and Kirby 1997;Pauza et al 1999Pauza et al , 2000Pauza et al , 2002aBatulevicius et al 2003Batulevicius et al , 2004Batulevicius et al , 2005. Structural organization of the intracardiac nerve plexus of the human and many animal models has been previously described using histological, histochemical and immunohistochemical methods (Bojsen-Moller and Tranum-Jensen 1971;Khabarova 1975;Stropus and Vaicekauskas 1978;Yuan et al 1994;Marron et al 1995;Singh et al 1996;Armour et al 1997;Pauza et al 1999Pauza et al , 2000Pauza et al , 2002aBatulevicius et al 2003Batulevicius et al , 2004Batulevicius et al , 2005Arora et al 2003;Jurgaitiene et al 2004;etc.). Histochemical study of the total adult human hearts, including hearts of children, infants, neonates and three fetuses of the late gestation, performed by Pauza et al (2000), have demonstrated the morphological pattern of the human epicardiac neural ganglionated plexus that contains 836 ± 76 ganglia.…”

Thermogenic potential and physiological relevance of human epicardial adipose tissue

“…However, a direct microcirculatory interconnection between the two has not been established so far. 23,24 Nonetheless, owing to its unique anatomic juxtaposition, numerous plausible physiological roles have been offered to epicardial fat including, but not limited to, that (1) it serves as the anatomic site for the cardiac nervous system, 25 (2) it serves to cushion the coronary arteries against pulse wave torsion, 14 (3) it serves as a heating blanket to protect the myocardium during hypothermia, 26,27 (4) it is an immunological tissue that serves to protect the myocardium and coronaries against pathogens and inflammatory activators 28 and (5) it serves to maintain fatty acid homeostasis in the coronary microcirculation. 5 In a seminal study looking at the anatomy, histology and biochemical properties of epicardial fat across a spectrum of species, epicardial fat was reported to exhibit a higher capacity for breakdown, synthesis and release of fatty acids relative to other intra-abdominal fat depots in guinea pigs.…”