Keijiro Nakamura1, Olujimi A Ajijola2, Eric Aliotta1, J Andrew Armour1, Jeffrey L Ardell1, Kalyanam Shivkumar1. 1. UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, University of California, Los Angeles, CA, USA; Department of Radiology, University of California, Los Angeles, CA, USA. 2. UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, University of California, Los Angeles, CA, USA; Department of Radiology, University of California, Los Angeles, CA, USA. Electronic address: oajijola@mednet.ucla.edu.
Abstract
OBJECTIVE: To determine whether chronic myocardial infarction (MI) induces structural and neurochemical changes in neurons within afferent and efferent ganglia mediating cardiac neurotransmission. METHODS: Neuronal somata in i) right atrial (RAGP) and ii) ventral interventricular ganglionated plexi (VIVGP), iii) stellate ganglia (SG) and iv) T1-2 dorsal root ganglia (DRG) bilaterally derived from normal (n=8) vs. chronic MI (n=8) porcine subjects were studied. We examined whether the morphology and neuronal nitric oxide synthase (nNOS) expression in soma of RAGP, VIVGP, DRG and SG neurons were altered as a consequence of chronic MI. In DRG, we also examined immunoreactivity of calcitonin gene related peptide (CGRP), a marker of afferent neurons. Chronic MI increased neuronal size and nNOS immunoreactivity in VIVGP (but not RAGP), as well as in the SG bilaterally. Across these ganglia, the increase in neuronal size was more pronounced in nNOS immunoreactive neurons. In the DRG, chronic MI also caused neuronal enlargement, and increased CGRP immunoreactivity. Further, DRG neurons expressing both nNOS and CGRP were increased in MI animals compared to controls, and represented a shift from double negative neurons. CONCLUSIONS: Chronic MI impacts diverse elements within the peripheral cardiac neuraxis. That chronic MI imposes such widespread, diverse remodeling of the peripheral cardiac neuraxis must be taken into consideration when contemplating neuronal regulation of the ischemic heart.
OBJECTIVE: To determine whether chronic myocardial infarction (MI) induces structural and neurochemical changes in neurons within afferent and efferent ganglia mediating cardiac neurotransmission. METHODS: Neuronal somata in i) right atrial (RAGP) and ii) ventral interventricular ganglionated plexi (VIVGP), iii) stellate ganglia (SG) and iv) T1-2 dorsal root ganglia (DRG) bilaterally derived from normal (n=8) vs. chronic MI (n=8) porcine subjects were studied. We examined whether the morphology and neuronal nitric oxide synthase (nNOS) expression in soma of RAGP, VIVGP, DRG and SG neurons were altered as a consequence of chronic MI. In DRG, we also examined immunoreactivity of calcitonin gene related peptide (CGRP), a marker of afferent neurons. Chronic MI increased neuronal size and nNOS immunoreactivity in VIVGP (but not RAGP), as well as in the SG bilaterally. Across these ganglia, the increase in neuronal size was more pronounced in nNOS immunoreactive neurons. In the DRG, chronic MI also caused neuronal enlargement, and increased CGRP immunoreactivity. Further, DRG neurons expressing both nNOS and CGRP were increased in MI animals compared to controls, and represented a shift from double negative neurons. CONCLUSIONS: Chronic MI impacts diverse elements within the peripheral cardiac neuraxis. That chronic MI imposes such widespread, diverse remodeling of the peripheral cardiac neuraxis must be taken into consideration when contemplating neuronal regulation of the ischemic heart.
Authors: D A Murphy; G W Thompson; J L Ardell; R McCraty; R S Stevenson; V E Sangalang; R Cardinal; M Wilkinson; S Craig; F M Smith; J G Kingma; J A Armour Journal: Ann Thorac Surg Date: 2000-06 Impact factor: 4.330
Authors: Koustubh B Sudarshan; Yuichi Hori; M Amer Swid; Alexander C Karavos; Christian Wooten; J Andrew Armour; Guy Kember; Olujimi A Ajijola Journal: Am J Physiol Heart Circ Physiol Date: 2021-07-02 Impact factor: 5.125
Authors: Sirisha Achanta; Jonathan Gorky; Clara Leung; Alison Moss; Shaina Robbins; Leonard Eisenman; Jin Chen; Susan Tappan; Maci Heal; Navid Farahani; Todd Huffman; Steve England; Zixi Jack Cheng; Rajanikanth Vadigepalli; James S Schwaber Journal: iScience Date: 2020-05-26
Authors: Clara Leung; Shaina Robbins; Alison Moss; Maci Heal; Mahyar Osanlouy; Richard Christie; Navid Farahani; Corey Monteith; Jin Chen; Peter Hunter; Susan Tappan; Rajanikanth Vadigepalli; Zixi Jack Cheng; James S Schwaber Journal: iScience Date: 2021-07-19