Firing Properties of Medullary Expiratory Neurons During Fictive Straining in Cats

Overview

Journal J Physiol Sci

Specialty Physiology

Date 2019 Oct 2

PMID 31571147

Authors

Sei-Ichi Sasaki

Ken Muramatsu

Masatoshi Niwa

Affiliations

Soon will be listed here.

Abstract

Expiratory (E) neurons in the caudal nucleus retroambigualis extend descending spinal axons to the lumbar and sacral spinal cord. Discharge rates of single E neurons were recorded to examine differences in activity of E neurons projecting to the lumbar or sacral spinal cord during fictive straining induced by distention of the colon with a balloon. Firing frequencies of E neurons with descending axons in the thoracic and lumbar spinal cord increased during the repetitive rise of rectum pressure, whereas those of E neurons with descending axons in the sacral spinal cord decreased. E neurons with descending axons in the thoracic/lumbar and sacral spinal cord exhibit different firing characteristics during the repetitive rise of rectum pressure when straining during defecation. The activity of abdominal nerves during fictive straining is in phase with changes in rectum pressure, but out of phase with the activity of E neurons.

References

FLOYD W, WALLS E . Electromyography of the sphincter ani externus in man. J Physiol. 1953; 122(3):599-609. PMC: 1366144. DOI: 10.1113/jphysiol.1953.sp005024. View

Billig I, Foris J, Enquist L, Card J, Yates B . Definition of neuronal circuitry controlling the activity of phrenic and abdominal motoneurons in the ferret using recombinant strains of pseudorabies virus. J Neurosci. 2000; 20(19):7446-54. PMC: 6772787. View

Boers J, Kirkwood P, de Weerd H, Holstege G . Ultrastructural evidence for direct excitatory retroambiguus projections to cutaneous trunci and abdominal external oblique muscle motoneurons in the cat. Brain Res Bull. 2005; 68(4):249-56. DOI: 10.1016/j.brainresbull.2005.08.011. View

Sasaki S, Uchino H, Uchino Y . Axon branching of medullary expiratory neurons in the lumbar and the sacral spinal cord of the cat. Brain Res. 1994; 648(2):229-38. DOI: 10.1016/0006-8993(94)91122-3. View

Fukuda H, Fukai K . Discharges of bulbar respiratory neurons during rhythmic straining evoked by activation of pelvic afferent fibers in dogs. Brain Res. 1988; 449(1-2):157-66. DOI: 10.1016/0006-8993(88)91034-7. View

Niwa M, Muramatsu K, Sasaki S . Discharge patterns of abdominal and pudendal nerves during induced defecation in anesthetized cats. J Physiol Sci. 2015; 65(3):223-31. PMC: 10717334. DOI: 10.1007/s12576-015-0362-y. View

Miller A, Tan L, Lakos S . Brainstem projections to cats' upper lumbar spinal cord: implications for abdominal muscle control. Brain Res. 1989; 493(2):348-56. DOI: 10.1016/0006-8993(89)91169-4. View

Boers J, Ford T, Holstege G, Kirkwood P . Functional heterogeneity among neurons in the nucleus retroambiguus with lumbosacral projections in female cats. J Neurophysiol. 2005; 94(4):2617-29. DOI: 10.1152/jn.00370.2005. View

Miller A, Ezure K, Suzuki I . Control of abdominal muscles by brain stem respiratory neurons in the cat. J Neurophysiol. 1985; 54(1):155-67. DOI: 10.1152/jn.1985.54.1.155. View

10.

Sasaki S, Uchino H . An electrophysiological demonstration of axonal projections of single ventral inspiratory neurons to the phrenic nucleus of the cat. Brain Res. 1995; 701(1-2):108-16. DOI: 10.1016/0006-8993(95)00985-1. View

11.

de Almeida A, Kirkwood P . Specificity in monosynaptic and disynaptic bulbospinal connections to thoracic motoneurones in the rat. J Physiol. 2013; 591(16):4043-63. PMC: 3764644. DOI: 10.1113/jphysiol.2013.256503. View

12.

Katada A, Sugimoto T, Utsumi K, Nonaka S, Sakamoto T . Functional role of ventral respiratory group expiratory neurons during vocalization. Neurosci Res. 1996; 26(3):225-33. DOI: 10.1016/s0168-0102(96)01104-2. View

13.

Miller A, Nonaka S, Siniaia M, Jakus J . Multifunctional ventral respiratory group: bulbospinal expiratory neurons play a role in pudendal discharge during vomiting. J Auton Nerv Syst. 1995; 54(3):253-60. DOI: 10.1016/0165-1838(95)00018-s. View

14.

Road J, Ford T, Kirkwood P . Connections between expiratory bulbospinal neurons and expiratory motoneurons in thoracic and upper lumbar segments of the spinal cord. J Neurophysiol. 2013; 109(7):1837-51. PMC: 3628013. DOI: 10.1152/jn.01008.2012. View

15.

Davis J, Plum F . Separation of descending spinal pathways to respiratory motoneurons. Exp Neurol. 1972; 34(1):78-94. DOI: 10.1016/0014-4886(72)90189-6. View

16.

Merrill E . The descending pathways from the lateral respiratory neurones in cats. J Physiol. 1971; 218 Suppl:82P-83P. View

17.

Kirkwood P, Sears T . Proceedings: Monosynaptic excitation of thoracic expiratory motoneurones from lateral respiratory neurones in the medulla of the cat. J Physiol. 1973; 234(2):87P-89P. View

18.

Kirkwood P . Synaptic excitation in the thoracic spinal cord from expiratory bulbospinal neurones in the cat. J Physiol. 1995; 484 ( Pt 1):201-25. PMC: 1157933. DOI: 10.1113/jphysiol.1995.sp020659. View

19.

Bishop B . REFLEX CONTROL OF ABDOMINAL MUSCLES DURING POSITIVE-PRESSURE BREATHING. J Appl Physiol. 1964; 19:224-32. DOI: 10.1152/jappl.1964.19.2.224. View

20.

Niwa M, Nakayama K, Sasaki S . Morphological study of external oblique motor nerves and nuclei in cats. Anat Sci Int. 2008; 83(1):17-25. DOI: 10.1111/j.1447-073x.2007.00196.x. View