D73. RECEPTOR INPUT OF AIRWAY NETWORKING

2012 ◽  
Keyword(s):  
Receptor Input

Mechanoreceptor modulation of endogenous respiratory rhythms in vertebrates

1990 ◽  
Vol 259 (5) ◽  
pp. R898-R910 ◽  
Author(s):  
W. K. Milsom
Keyword(s):  
Breathing Pattern ◽  
Respiratory Rhythm ◽  
Flow Distribution ◽  
Respiratory Pattern ◽  
Respiratory Drive ◽  
Lung Inflation ◽  
Phase Switching ◽  
Separate Control ◽  
Regulation Of Breathing ◽  
Receptor Input

While pulmonary mechanoreceptors appear to play little or no role in determining the eupneic breathing pattern in some species of vertebrates, they do in others as well as in all species under conditions of elevated respiratory drive. Tonic and phasic inputs from this receptor group have independent roles in determining breathing pattern. Thus withholding lung inflation produces very different results from receptor denervation. There are at least five phases to the respiratory cycle that appear to be under separate control. Tonic receptor input is involved primarily in regulating the length of the respiratory pause, which can occur at the end of inspiration or expiration, depending on the species. Phasic receptor input has different effects during different phases of the cycle as well as different effects at different times during a single phase. This activity contributes to phase switching during the ventilation cycle and thus to the regulation of breathing frequency and tidal volume. The significance of the modulatory effects of phasic input on the duration of different phases of the ventilation cycle is not totally clear, but the evidence suggests that phasic input acts to stabilize the respiratory pattern and may be instrumental in optimizing the breathing pattern in terms of ergometric costs. This appears to be the case in all vertebrate classes, despite dramatic differences in the mechanical events associated with ventilation arising from different respiratory pumps. These receptors also appear to have significant roles other than those associated with modulation of respiratory rhythm, particularly in lower vertebrates. Many of these roles, such as maintaining the integrity of the gill curtain in fish or buoyancy control and regulation of blood flow distribution in reptiles, may be as important as their role in modulating the endogenous rhythm.

scholarly journals Dysregulated RasGRP1 Responds to Cytokine Receptor Input in T Cell Leukemogenesis

2013 ◽  
Vol 6 (268) ◽  
pp. ra21-ra21 ◽  
Author(s):  
C. Hartzell ◽  
O. Ksionda ◽  
E. Lemmens ◽  
K. Coakley ◽  
M. Yang ◽  
...  
Keyword(s):  
T Cell ◽  
Cytokine Receptor ◽  
Receptor Input ◽  
T Cell Leukemogenesis

scholarly journals Proprioceptive Reflexes Change when an Insect Assumes an Active, Learned Posture

1983 ◽  
Vol 107 (1) ◽  
pp. 385-390
Author(s):  
SASHA N. ZILL ◽  
ROBIN R. FORMAN
Keyword(s):  
Joint Angle ◽  
Chordotonal Organ ◽  
Afferent Activity ◽  
Reflex Responses ◽  
Proprioceptive Reflexes ◽  
Receptor Input

Imposed changes in activity of a joint angle receptor of the locust leg, the metathoracic femoral chordotonal organ, produce variable, phasic reflex responses in a leg extensor motoneurone in untrained animals. After training the locust to maintain a posture in extension beyond a minimum required joint angle, these reflexes are consistently tonic and excitatory. This plasticity of reflex responsiveness permits the locust to couple motoneurone firing to afferent activity when receptor input is behaviourally relevant.

scholarly journals Directional reorientation of migrating neutrophils is limited by suppression of receptor input signaling at the cell rear through myosin II activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Amalia Hadjitheodorou ◽  
George R. R. Bell ◽  
Felix Ellett ◽  
Shashank Shastry ◽  
Daniel Irimia ◽  
...  
Keyword(s):  
Light Chain ◽  
Large Scale ◽  
Myosin Ii ◽  
Receptor Activation ◽  
Microfluidic Channels ◽  
Myosin Regulatory Light Chain ◽  
Polarized Cells ◽  
Primary Determinant ◽  
Receptor Input ◽  
Target Locations

AbstractTo migrate efficiently to target locations, cells must integrate receptor inputs while maintaining polarity: a distinct front that leads and a rear that follows. Here we investigate what is necessary to overwrite pre-existing front-rear polarity in neutrophil-like HL60 cells migrating inside straight microfluidic channels. Using subcellular optogenetic receptor activation, we show that receptor inputs can reorient weakly polarized cells, but the rear of strongly polarized cells is refractory to new inputs. Transient stimulation reveals a multi-step repolarization process, confirming that cell rear sensitivity to receptor input is the primary determinant of large-scale directional reversal. We demonstrate that the RhoA/ROCK/myosin II pathway limits the ability of receptor inputs to signal to Cdc42 and reorient migrating neutrophils. We discover that by tuning the phosphorylation of myosin regulatory light chain we can modulate the activity and localization of myosin II and thus the amenability of the cell rear to ‘listen’ to receptor inputs and respond to directional reprogramming.

Circulatory responses to onset of exercise: role of arterial and cardiac baroreflexes

1985 ◽  
Vol 248 (4) ◽  
pp. H457-H467 ◽  
Author(s):  
J. Ludbrook ◽  
W. F. Graham
Keyword(s):  
Arterial Pressure ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Systemic Vascular Resistance Index ◽  
Receptor Input ◽  
Cardiovascular Variables ◽  
Tonic Reflex ◽  
Cardiac Receptors

Six rabbits were exercised on a moving belt at 13 m/min for 60's. Heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), and systemic vascular resistance index (SVRI) were measured. Exercise was done under the following four permutations of input from baroreceptors (B) and cardiac receptors (C): BC, both inputs present; B, only baroreceptor input (intrapericardial procaine); C, only cardiac receptor input (surgical barodenervation); 0, both inputs deleted. The reflex effects on SVRI of the two inputs were calculated as (B - 0) and (C - 0) and their interaction as (BC - 0) - [(B - 0) + (C - 0)]. The effects of baroreceptor input plus interaction on all cardiovascular variables were also calculated, as (BC - C). At rest, (B - 0) and (C - 0) each tonically depressed SVRI without interacting, and (BC - C) tonically depressed SVRI, MAP, and HR. Within 10 s of the start of exercise these tonic effects were abolished, although a small, SVRI-lowering interaction appeared. Suppression of the tonic reflex effects of arterial baroreceptor and cardiac receptor input supported systemic vascular resistance at the onset of exercise and contributed to the rise of arterial pressure.

Central integration of pulmonary stretch receptor input in the control of expiration

1982 ◽  
Vol 52 (5) ◽  
pp. 1296-1315 ◽  
Author(s):  
E. J. Zuperku ◽  
F. A. Hopp ◽  
J. P. Kampine
Keyword(s):  
Temporal Summation ◽  
Stretch Receptor ◽  
Common Mechanism ◽  
Central Processing ◽  
Long Time ◽  
Residual Capacity ◽  
Receptor Input ◽  
Discharge Patterns ◽  
Lung Deflation ◽  
Pulmonary Stretch Receptor

The dynamics of the central processing of the discharge pattern from vagal pulmonary afferents that mediate the expiratory facilitatory reflex have been investigated. These studies involved the development of mathematical models based on analogs of neurophysiological principles such as temporal summation and threshold crossing. These models, which are capable of predicting the expiratory duration for arbitrary discharge patterns, were verified through comparison of their prediction with experimentally obtained relationships between expiratory duration (TE) and waveform parameters of various input patterns. These relationships were obtained by electrical activation of the largest vagal afferent fibers in bilaterally vagotomized, pentobarbital-anesthetized dogs. A parallel two-component model with long time constants (ca. 0.8 and 18 s) was best able to describe the experimental responses. This model suggests that 1) central integration of pulmonary stretch receptor (PSR) input is similar to long time-constant temporal summation; 2) central inspiratory inhibition (no vagal input) may share a common mechanism with vagal processing; 3) PSR-induced inhibition is a linear function of discharge frequency; and 4) TE depends on both the trajectory of lung deflation and the tonic activity at functional residual capacity. These characteristics embody information regarding specific neural arrangements and properties within the respiratory centers.

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