Biomaterial Database

Long-term facilitation of phrenic nerve activity in cats: responses and short time scale correlations of medullary neurones. 1996

K F Morris, and A Arata, and R Shannon, and B G Lindsey

Department of Physiology and Biophysics, University of South Florida Medical Center, Tampa 33612-4799, USA.

1. Stimulation of either peripheral chemoreceptors or nucleus raphe obscurus results in long-term facilitation of phrenic motoneurone activity. The first objective of this work was to measure the concurrent responses of neurones in the nucleus raphe obscurus, the nucleus tractus solitarii, and the regions of the retrofacial nucleus, nucleus ambiguus and nucleus retroambigualis during induction of long-term facilitation. A second goal was to assess functional relationships of the chemoresponsive raphe neurones with neurones in the other monitored locations and with phrenic motoneurones. 2. Up to thirty single medullary neurones and phrenic nerve efferent activity were recorded simultaneously in fifteen anaesthetized, paralysed, vagotomized, artificially ventilated adult cats. Carotid chemoreceptors were stimulated by close arterial injection of 200 microliters of CO2-saturated saline solution. Spike trains were analysed with cycle-triggered histograms and two statistical tests for respiratory modulation. Peristimulus-time histograms and cumulative sum histograms were used to assess responses to stimulation. Cross-correlation was used to test for non-random temporal relationships between spike trains. Spike-triggered average histograms provided evidence for functional associations with phrenic motoneurones. 3. One hundred and thirteen of 348 neurones were monitored in the nucleus raphe obscurus. The firing rates of twenty-nine raphe neurones increased during stimulation; eighteen decreased. In twenty-one pairs of concurrently monitored raphe neurones, the firing rate of one increased its activity during stimulation then decreased, while the other showed an increase that began as the rate of the former declined. Eighteen chemoresponsive raphe neurones had short time scale features in their phrenic spike-triggered averages. Short time scale features were found in cross-correlograms from 184 of 1407 neurone pairs. 4. The data suggest parallel routes by which carotid chemoreceptors influence medullary raphe neurones and support the hypotheses that mid-line respiratory-related neuronal assemblies transform information from those receptors and regulate the gain of respiratory motor output.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010791	Phrenic Nerve	The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.	Nerve, Phrenic,Nerves, Phrenic,Phrenic Nerves
D011903	Raphe Nuclei	Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.	Caudal Linear Nucleus of the Raphe,Interfascicular Nucleus,Nucleus Incertus,Rostral Linear Nucleus of Raphe,Rostral Linear Nucleus of the Raphe,Superior Central Nucleus,Central Nucleus, Superior,Incertus, Nucleus,Nuclei, Raphe,Nucleus, Interfascicular,Nucleus, Raphe,Nucleus, Superior Central,Raphe Nucleus
D012143	Respiratory Physiological Phenomena	Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.	Respiratory Physiologic Processes,Respiratory Physiological Processes,Respiratory Physiology,Physiology, Respiratory,Pulmonary Physiological Phenomena,Pulmonary Physiological Phenomenon,Pulmonary Physiological Process,Pulmonary Physiological Processes,Respiratory Physiological Concepts,Respiratory Physiological Phenomenon,Respiratory Physiological Process,Concept, Respiratory Physiological,Concepts, Respiratory Physiological,Phenomena, Pulmonary Physiological,Phenomena, Respiratory Physiological,Phenomenas, Pulmonary Physiological,Phenomenas, Respiratory Physiological,Phenomenon, Pulmonary Physiological,Phenomenon, Respiratory Physiological,Phenomenons, Pulmonary Physiological,Phenomenons, Respiratory Physiological,Physiologic Processes, Respiratory,Physiological Concept, Respiratory,Physiological Concepts, Respiratory,Physiological Phenomena, Pulmonary,Physiological Phenomena, Respiratory,Physiological Phenomenas, Pulmonary,Physiological Phenomenas, Respiratory,Physiological Phenomenon, Pulmonary,Physiological Phenomenon, Respiratory,Physiological Phenomenons, Pulmonary,Physiological Phenomenons, Respiratory,Physiological Process, Pulmonary,Physiological Process, Respiratory,Physiological Processes, Pulmonary,Physiological Processes, Respiratory,Process, Pulmonary Physiological,Process, Respiratory Physiological,Processes, Pulmonary Physiological,Pulmonary Physiological Phenomenas,Pulmonary Physiological Phenomenons,Respiratory Physiological Concept,Respiratory Physiological Phenomenas,Respiratory Physiological Phenomenons
D002346	Carotid Sinus	The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.	Sinus, Carotid
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D002628	Chemoreceptor Cells	Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.	Chemoreceptive Cells,Cell, Chemoreceptive,Cell, Chemoreceptor,Cells, Chemoreceptive,Cells, Chemoreceptor,Chemoreceptive Cell,Chemoreceptor Cell
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia