Comparative anatomical study of the autonomic cardiac nervous system in macaque monkeys

Abstract

The main aim of this study was to clarify the general morphology of the autonomic cardiac nervous system in macaque monkeys. A submacroscopic comparative anatomical study of the autonomic cardiac nervous system was performed by examining 22 sides of 11 bodies of four species of macaque monkeys, including some previously unreported species (pig-tailed and stump-tailed monkeys), under a surgical stereomicroscope. The following results were obtained. 1) The basic arrangement of the autonomic cardiac nervous system is constant in all examined macaques. 2) A superior cardiac nerve originating from the superior cervical ganglion was not observed, whereas the thoracic cardiac nerve originating from the sympathetic trunk/ganglia under the cervicothoracic ganglion was rarely observed in all the examined macaques. 3) The main cardiac nerve is the middle cardiac nerve originating from the middle cervical ganglion, similar to the situation in humans. 4) Although the superior, inferior, and thoracic cardiac branches of the vagus nerve were consistently observed, the left thoracic cardiac branch is rarely absent because of its lower origin to the heart. 5) The cranial autonomic nerves tend to distribute into the heart medially (arterial porta), and the caudal autonomic nerves tend to distribute into the heart laterally (venous porta). To comprehend the comparative morphological and evolutionary changes more completely, these results were compared with our previous studies and some references. Consequently, differences in the sympathetic cardiac nerves of macaques and humans are recognized, in spite of the similar morphologies of the vagal cardiac branches. These differences include the composition of the cervicothoracic ganglion, the lower positions of the middle cervical and cervicothoracic ganglia, and the narrow range for the origin of the cardiac nerves in macaques compared to that in humans.

Detailed Comparative Anatomy of the Extrinsic Cardiac Nerve Plexus and Postnatal Reorganization of the Cardiac Position and Innervation in the Great Apes: Orangutans, Gorillas, and Chimpanzees

“…These studies have revealed a variety of sizes, numbers, and courses of neurons, cardiac ganglia, and subplexuses, depending on age and species, and they showed the importance of comparative anatomy. We have also conducted anatomical and evolutionary morphological research on the primate extrinsic cardiac nerve plexus (ECNP) in Strepsirrhini (Kawashima and Thorington,2011), New World monkeys (Kawashima et al,2009), Old World monkeys (Kawashima and Sato,2000; Kawashima et al,2001,2005,2007), gibbons (Kawashima et al,2008), and humans (Kawashima,2005,2011; Kawashima and Sasaki,2005,2007). Consequently, somatic body structures such as bone, muscle, and nerve supply are modified for functional adaptations, but our comparative anatomical studies suggest that the primate ECNP may have preserved its evolutionary history in close alignment with phylogeny.…”

Comparative Physiology, Growth, and Development

“…Morphometric study of the marmoset heart found heart weight as a proportion of body weight (0.51 ± 0.38%) consistent with that of other mammals, and there was no significant sex difference [173]. The comparative anatomy of the autonomic innervation of the primate heart compared with the human heart shows no difference in vagal innervation and minor craniad shifts in the sympathetic ganglia and a more definite thoracic cardiac nerve in apes [177,178]. An anatomic study of the conduction system of the rhesus has been reported [175], and immunohistochemical markers of autonomic nerve fibers and the conducting system of the adult cynomolgus heart have been described [176].…”

Noninvasive cardiac psychophysiology as a tool for translational science with marmosets

“…Luckily, many autonomic physiological measures that are used in humans can also be deployed in nonhuman animals because of the conservation of the autonomic nervous system across phylogeny, especially within primates (Kawa, shima, Sato, Akita, & Sasaki, ; Kawashima, Thorington, & Whatton, ). While there is some history of recording these signals in nonhuman animals, rarely do scientists differentiate activity of the two major branches of the autonomic nervous system (ANS; e.g., measures of heart rate reflect activity in both branches; Berntson, Quigley, & Lozano, ; for a review).…”