Biomaterial Database

Respiratory load compensation. III. Role of spinal cord afferents. 1993

D T Frazier, and F Xu, and L Y Lee, and R F Taylor

Department of Physiology and Biophysics, University of Kentucky, Lexington 40536.

In a previous study, we reported that inspiratory tracheal occlusion (TO) significantly inhibited the motor drive to the diaphragm in a decerebellated bilaterally vagotomized preparation (J. Appl. Physiol. 75:675-681, 1993). The hypothesis to be tested in the present study was that respiratory muscle afferents activated by inspiratory TO provided the inputs responsible for the observed inhibition. Adult cats were anesthetized, tracheotomized, and instrumented with diaphragm electromyographic (EMGdi) recording electrodes. The cerebellum, vagi, and dorsal spinal cord (C2-T2) were surgically exposed. Inspiratory TO was applied before and after cold blockade of the dorsal cord (C6) or dorsal root (C3-6) transection in the intact and decerebellated vagotomized cat. Respiratory timing (inspiratory and expiratory duration) was determined from the EMGdi record, and the peak integrated EMGdi (integral of EMGdi) response was used as an index of respiratory motor drive. Our results showed that 1) cold blockade at the dorsal C6 level in an intact preparation significantly increased the peak of the integral of EMGdi response to TO and was reversible upon rewarming; 2) as previously reported, decerebellation coupled with bilateral vagotomy significantly decreased the peak integral of EMGdi response to TO with no effect on timing; 3) cold blockade (-1 degree C) of the dorsal cord at C6 significantly attenuated this inhibition, and subsequent dorsal rhizotomy at C3-6 completely abolished this inhibition; and 4) decerebellation, cold blockade of the dorsal cord (C6), and dorsal rhizotomy (C3-6) did not significantly affect baseline values in bilaterally vagotomized cats.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009407	Nerve Block	Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.	Chemical Neurolysis,Chemodenervation,Nerve Blockade,Block, Nerve,Blockade, Nerve,Blockades, Nerve,Blocks, Nerve,Chemical Neurolyses,Chemodenervations,Nerve Blockades,Nerve Blocks,Neurolyses, Chemical,Neurolysis, Chemical
D009431	Neural Conduction	The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.	Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
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
D012129	Respiratory Function Tests	Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.	Lung Function Tests,Pulmonary Function Tests,Function Test, Pulmonary,Function Tests, Pulmonary,Pulmonary Function Test,Test, Pulmonary Function,Tests, Pulmonary Function,Function Test, Lung,Function Test, Respiratory,Function Tests, Lung,Function Tests, Respiratory,Lung Function Test,Respiratory Function Test,Test, Lung Function,Test, Respiratory Function,Tests, Lung Function,Tests, Respiratory Function
D012132	Respiratory Muscles	These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.	Ventilatory Muscles,Respiratory Muscle,Muscle, Respiratory,Muscle, Ventilatory,Muscles, Respiratory,Muscles, Ventilatory,Ventilatory Muscle
D001784	Blood Gas Analysis	Measurement of oxygen and carbon dioxide in the blood.	Analysis, Blood Gas,Analyses, Blood Gas,Blood Gas Analyses,Gas Analyses, Blood,Gas Analysis, Blood
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
D002531	Cerebellum	The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.	Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D003080	Cold Temperature	An absence of warmth or heat or a temperature notably below an accustomed norm.	Cold,Cold Temperatures,Temperature, Cold,Temperatures, Cold