Role of phrenic nerve afferents in the control of breathing

1991 ◽  
Vol 70 (2) ◽  
pp. 491-496 ◽  
Author(s):  
D. T. Frazier ◽  
W. R. Revelette
Keyword(s):  
Phrenic Nerve ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
Control Of Breathing ◽  
Motor Drive ◽  
Central Projections ◽  
Load Compensation ◽  
The Central Nervous System ◽  
Stimulation Of

A long-held belief is that respiratory-related reflexes mediated by afferents in the diaphragm are weak or absent. However, recent data suggest that diaphragmatic afferents are capable of altering ventilatory motor drive as well as influencing perception of added inspiratory loads in humans. This review describes the sensory elements of the diaphragm, their central projections, and their functional significance in the control of respiratory muscle activation. The reflexes elicited by electrical stimulation of phrenic nerve afferents and the contribution of diaphragmatic afferents in respiratory load compensation and perception are considered. There is growing evidence that phrenic nerve afferents are activated under a variety of conditions. However, the significance of this input to the central nervous system is yet to be discerned.

Motor unit territories supplied by primary branches of the phrenic nerve

1989 ◽  
Vol 66 (1) ◽  
pp. 61-71 ◽  
Author(s):  
C. G. Hammond ◽  
D. C. Gordon ◽  
J. T. Fisher ◽  
F. J. Richmond
Keyword(s):  
Motor Unit ◽  
Phrenic Nerve ◽  
Motor Units ◽  
Glycogen Depletion ◽  
Precise Analysis ◽  
The Central Nervous System ◽  
Evoked Activity ◽  
Crural Diaphragm ◽  
Emg Electrodes ◽  
Stimulation Of

Recent studies have demonstrated that, under certain circumstances, the diaphragm does not contract as a homogeneous unit. These observations suggest that motor units may not be randomly distributed throughout the muscle but confined to localized subvolumes. In the present study, electromyographic (EMG) and glycogen depletion methods were combined to investigate the organization of motor units supplied by the primary branches of the phrenic nerve in the cat. Four primary branches are generally present, one branch to the crus and three branches to the sternocostal region. The gross motor-unit territory of each of the four phrenic primary branches was determined by stimulating each nerve separately, while recording from nine EMG electrodes distributed over the hemidiaphragm. Stimulation of the crural branch evoked activity in the ipsilateral crus, whereas stimulation of each of the remaining branches evoked activity in discrete but overlapping areas of the sternocostal diaphragm. A more precise analysis of the distribution and borders of the motor territories was obtained by mapping regions depleted of muscle glycogen due to stimulation of each primary branch for 90 min. Glycogen depletion results closely matched the EMG findings of a localized distribution of motor units served by single primary branches. Stimulation of the crural branch typically caused depletion of the ipsilateral crus, whereas the sternocostal branches each served a striplike compartment. In the majority of cases, the borders of the sternocostal compartments were relatively abrupt and consisted of a 1- to 2-mm transition zone of depleted and nondepleted fibers. These studies demonstrate that motor unit territories of the primary branches of the phrenic nerve are highly delineated. This compartmentalization provides the central nervous system with the potential for a more precise regional motor control of costal and crural diaphragm than previously suspected.

Effects on breathing of ventrolateral medullary cooling in awake goats

1995 ◽  
Vol 78 (1) ◽  
pp. 258-265 ◽  
Author(s):  
H. V. Forster ◽  
P. J. Ohtake ◽  
L. G. Pan ◽  
T. F. Lowry ◽  
M. J. Korducki ◽  
...  
Keyword(s):  
Pulmonary Ventilation ◽  
Control Level ◽  
Control Of Breathing ◽  
Ventrolateral Medulla ◽  
Neuronal Dysfunction ◽  
Subsequent Increase ◽  
Initial Decrease ◽  
Caudal Area ◽  
Stimulation Of

Our objective was to investigate the role of the ventrolateral medulla (VLM) in the control of breathing during the awake state. In 17 awake adult goats, chronically implanted thermodes were used to cool the VLM and thereby cause reversible neuronal dysfunction in all or portions of the area between the first hypoglossal rootlet and the ponto-medullary junction (so-called area M (rostral) and area S). Within 5 s after the initiation of cooling, 60–100% of areas M and S, pulmonary ventilation (VE) decreased uniformly over conditions of eucapnia, hypercapnia, hypoxia, and exercise (P < 0.05). Between 10 and 20 s of cooling, the reduction in VE was approximately 10% greater during eucapnia and hypercapnia than during hypoxia and exercise (P < 0.05). For the remaining 10 s of cooling and for about 1 min after cooling, VE increased to and above control level. Cooling only rostral area M or only caudal area M-rostral area S affected breathing qualitatively in the same manner as when 60–100% of areas M and S were cooled. However, cooling caudal area S had effects that differed significantly (P < 0.05) from more rostral cooling in that the initial decrease in VE was attenuated and the subsequent increase was accentuated. The initial uniform decreased VE during cooling suggests that superficial VLM nonchemoreceptor neurons facilitate breathing. The subsequent relatively greater effect of cooling during eucapnia and hypercapnia probably reflects dysfunction of chemoreceptor-related neurons that normally stimulate breathing. The stimulation of breathing during the later stages and after cooling may suggest that some VLM neurons inhibit breathing.

scholarly journals Role of Catecholamine in Pressor Responses to Stimulation of the Central Nervous System

1963 ◽  
Vol 4 (2) ◽  
pp. 118-130 ◽  
Author(s):  
Hideo UEDA ◽  
Akiyuki YAMADA ◽  
Hitoshi GOTO ◽  
Iwao ITO ◽  
Yutaka TAKABATAKE ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Pressor Responses ◽  
The Central Nervous System ◽  
Stimulation Of

Vasodilation in skeletal muscle during activation of patellar reflex

1961 ◽  
Vol 200 (4) ◽  
pp. 685-688 ◽  
Author(s):  
R. R. Sonnenschein
Keyword(s):  
Skeletal Muscle ◽  
Central Nervous System ◽  
Muscle Activation ◽  
Motor Nerve ◽  
Sympathetic Block ◽  
Vascular Response ◽  
Vascular Responses ◽  
The Central Nervous System ◽  
Decerebrate Cats ◽  
Stimulation Of

The muscular hyperemia accompanying the patellar reflex was studied in decerebrate cats with and without sympathetic block, and compared with the vascular response resulting from equivalent muscle activation through stimulation of the intact or centrally blocked motor nerve. No obvious differences were seen in the vascular responses under these conditions, except possibly in the latency and pattern of onset of the response. It is concluded that, with the possible exception of the latter feature, the vasodilation accompanying the patellar reflex is independent of the central nervous system.

The role of central vasopressin receptors in the modulation of autonomic cardiovascular controls: a spectral analysis study

2006 ◽  
Vol 291 (6) ◽  
pp. R1579-R1591 ◽  
Author(s):  
Sanja Milutinović ◽  
David Murphy ◽  
Nina Japundžić-Žigon
Keyword(s):  
Blood Pressure ◽  
Spectral Analysis ◽  
Low Frequency ◽  
Systolic Arterial Pressure ◽  
Short Term ◽  
Vasopressin Receptors ◽  
The Central Nervous System ◽  
Respiratory Stimulation ◽  
Stimulation Of

Although it has been suggested that vasopressin (VP) acts within the central nervous system to modulate autonomic cardiovascular controls, the mechanisms involved are not understood. Using nonpeptide, selective V1a, V1b, and V2 antagonists, in conscious rats, we assessed the roles of central VP receptors, under basal conditions, after the central application of exogenous VP, and after immobilization, on cardiovascular short-term variability. Equidistant sampling of blood pressure (BP) and heart rate (HR) at 20 Hz allowed direct spectral analysis in very-low frequency (VLF-BP), low-frequency (LF-BP), and high-frequency (HF-BP) blood pressure domains. The effect of VP antagonists and of exogenous VP on body temperature (Tb) was also investigated. Under basal conditions, V1a antagonist increased HF-BP and Tb, and this was prevented by metamizol. V1b antagonist enhanced HF-BP without affecting Tb, and V2 antagonist increased VLF-BP variability which could be prevented by quinapril. Immobilization increased BP, LF-BP, HF-BP, and HF-HR variability. V1a antagonist prevented BP and HR variability changes induced by immobilization and potentiated tachycardia. V1b antagonist prevented BP but not HR variability changes, whereas V2 antagonist had no effect. Exogenous VP increased systolic arterial pressure (SAP) and HF-SAP variability, and this was prevented by V1a and V1b but not V2 antagonist pretreatment. Our results suggest that, under basal conditions, VP, by stimulation of V1a, V1b, and cognate V2 receptors, buffers BP variability, mostly due to thermoregulation. Immobilization and exogenous VP, by stimulation of V1a or V1b, but not V2 receptors, increases BP variability, revealing cardiorespiratory adjustment to stress and respiratory stimulation, respectively.

scholarly journals Role of L-glutamate in aggression

2016 ◽  
Vol 72 (12) ◽  
pp. 740-744
Author(s):  
Bogdan Feliks Kania ◽  
Danuta Wrońska
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Steroid Receptors ◽  
Cation Channels ◽  
Metabotropic Receptor ◽  
Ionotropic Receptors ◽  
The Central Nervous System ◽  
G Protein Coupled ◽  
Stimulation Of

L-glutamate is one of major excitatory transmitters (along with aspartic, kainate acids and glycine) in the central nervous system and/or the peripheral nervous system. It mediates interaction through the stimulation of various ionotropic receptors families (ligand gated cation channels) and metabotropic receptor families (G-protein coupled). In this review, we describe the molecular composition of these glutamatergic receptors and discuss their neuropharmacology, particularly with respect to their roles in animal social behaviors and, particularly, in aggression. It is also known, that during aggression different interactions occur in the nervous system among glutamate, serotonin, vasopressin, oxytocin, dopamine, GABA and steroid receptors.

Respiratory load compensation. III. Role of spinal cord afferents

1993 ◽  
Vol 75 (2) ◽  
pp. 682-687 ◽  
Author(s):  
D. T. Frazier ◽  
F. Xu ◽  
L. Y. Lee ◽  
R. F. Taylor
Keyword(s):  
Spinal Cord ◽  
Muscle Afferents ◽  
Motor Drive ◽  
Dorsal Spinal Cord ◽  
Load Compensation ◽  
Dorsal Rhizotomy ◽  
Before And After ◽  
Bilateral Vagotomy ◽  
Adult Cats

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)

Effect of phrenic afferent stimulation on pattern of respiratory muscle activation

1992 ◽  
Vol 73 (2) ◽  
pp. 563-570 ◽  
Author(s):  
M. E. Ward ◽  
A. Deschamps ◽  
C. Roussos ◽  
S. N. Hussain
Keyword(s):  
Tidal Volume ◽  
Phrenic Nerve ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
Afferent Fiber ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Breathing Frequency ◽  
Inspiratory Muscles

Ventilation and electromyogram (EMG) activities of the right hemidiaphragm, parasternal intercostal, triangularis sterni, transversus abdominis, genioglossus, and alae nasi muscles were measured before and during central stimulation of the left thoracic phrenic nerve in 10 alpha-chloralose anesthetized vagotomized dogs. Pressure in the carotid sinuses was fixed to maintain baroreflex activity constant. The nerve was stimulated for 1 min with a frequency of 40 Hz and stimulus duration of 1 ms at voltages of 5, 10, 20, and 30 times twitch threshold (TT). At five times TT, no change in ventilation or EMG activity occurred. At 10 times TT, neither tidal volume nor breathing frequency increased sufficiently to reach statistical significance, although the change in their product (minute ventilation) was significant (P less than 0.05). At 20 and 30 times TT, increases in both breathing frequency and tidal volume were significant. At these stimulus intensities, the increases in ventilation were accompanied by approximately equal increases in the activity of the diaphragm, parasternal, and alae nasi muscles. The increase in genioglossus activity was much greater than that of the other inspiratory muscles. Phrenic nerve stimulation also elicited inhomogeneous activation of the expiratory muscles. The transversus abdominis activity increased significantly at intensities from 10 to 30 times TT, whereas the activity of the triangularis sterni remained unchanged. The high stimulation intensities required suggest that the activation of afferent fiber groups III and IV is involved in the response. We conclude that thin-fiber phrenic afferent activation exerts a nonuniform effect on the upper airway, rib cage, and abdominal muscles and may play a role in the control of respiratory muscle recruitment.

scholarly journals Role of GABA-A and GABA-B receptors of the brain in the hypothalamo-pituitary-testicular regulation by the negative feedback mechanism

1995 ◽  
Vol 41 (4) ◽  
pp. 36-38
Author(s):  
Ye. V. V. Naumenko ◽  
A. V. Amikishiyeva ◽  
L. I. Serova
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Negative Feedback ◽  
Feedback Mechanism ◽  
Gaba A ◽  
Negative Feedback Mechanism ◽  
The Central Nervous System ◽  
The Brain ◽  
Stimulation Of

The role of gamma-aminobutyric acid (GABA) of the brain and its receptors in the hypothalamo-pituitary-testicular (HPT) regulation by the negative feedback mechanism was for the first time studied in sham-operated and unilaterally castrated adult Wister rats. Increased level of GABA in the central nervous system following an injection of GABA transaminase inhibitor, aminoacetic acid, into the lateral ventricle of the brain was associated with activation of a compensatory increase of testosterone level in the blood, caused by unilateral castration. GABA effect is mediated through the receptors. Muscimol stimulation of GABA-A receptors of the central nervous system activated and their blocking with bicucullin inhibited a compensatory increase of testosterone level in the blood caused by hemicastration. Baclofen stimulation of cerebral GABA-B receptors was associated with an inhibition and their saclofen blocking with stimulation of the level of male sex steroid hormone in the blood following unilateral castration. A conclusion is made about participation of GABAergic mechanisms of the brain in the regulation of HPT function via the negative feedback mechanism

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