Afferent Inputs to Breathing: Respiratory Sensation

2011 ◽  
Author(s):  
Fred W. Zechman ◽  
Ronald L. Wiley
Keyword(s):  
Respiratory Sensation ◽  
Afferent Inputs

scholarly journals Early Lipid Raft-Related Changes: Interplay between Unilateral Denervation and Hindlimb Suspension

2021 ◽  
Vol 22 (5) ◽  
pp. 2239
Author(s):  
Irina G. Bryndina ◽  
Maria N. Shalagina ◽  
Vladimir A. Protopopov ◽  
Alexey V. Sekunov ◽  
Andrey L. Zefirov ◽  
...  
Keyword(s):  
Lipid Raft ◽  
Hindlimb Suspension ◽  
Short Term ◽  
Antiapoptotic Protein ◽  
Muscle Disuse ◽  
Proapoptotic Protein ◽  
Raft Fraction ◽  
Rat Soleus Muscle ◽  
Afferent Inputs ◽  
Underlying Mechanisms

Muscle disuse and denervation leads to muscle atrophy, but underlying mechanisms can be different. Previously, we have found ceramide (Cer) accumulation and lipid raft disruption after acute hindlimb suspension (HS), a model of muscle disuse. Herein, using biochemical and fluorescent approaches the influence of unilateral denervation itself and in combination with short-term HS on membrane-related parameters of rat soleus muscle was studied. Denervation increased immunoexpression of sphingomyelinase and Cer in plasmalemmal regions, but decreased Cer content in the raft fraction and enhanced lipid raft integrity. Preliminary denervation suppressed (1) HS-induced Cer accumulation in plasmalemmal regions, shown for both nonraft and raft-fractions; (2) HS-mediated decrease in lipid raft integrity. Similar to denervation, inhibition of the sciatic nerve afferents with capsaicin itself increased Cer plasmalemmal immunoexpression, but attenuated the membrane-related effects of HS. Finally, both denervation and capsaicin treatment increased immunoexpression of proapoptotic protein Bax and inhibited HS-driven increase in antiapoptotic protein Bcl-2. Thus, denervation can increase lipid raft formation and attenuate HS-induced alterations probably due to decrease of Cer levels in the raft fraction. The effects of denervation could be at least partially caused by the loss of afferentation. The study points to the importance of motor and afferent inputs in control of Cer distribution and thereby stability of lipid rafts in the junctional and extrajunctional membranes of the muscle.

scholarly journals The path from trigeminal asymmetry to cognitive impairment: a behavioral and molecular study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Paola Tramonti Fantozzi ◽  
Giulia Lazzarini ◽  
Vincenzo De Cicco ◽  
Angela Briganti ◽  
Serena Argento ◽  
...  
Keyword(s):  
Pupil Size ◽  
Muscle Spindles ◽  
Molecular Study ◽  
Contralateral Side ◽  
Acute Effects ◽  
Adult Rats ◽  
Afferent Inputs ◽  
Acute And Chronic Effects ◽  
The Brain ◽  
Mandibular Branch

AbstractTrigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input.

scholarly journals Afferent Inputs to Neurotransmitter-Defined Cell Types in the Ventral Tegmental Area

Cell Reports ◽  
2016 ◽  
Vol 15 (12) ◽  
pp. 2796-2808 ◽  
Author(s):  
Lauren Faget ◽  
Fumitaka Osakada ◽  
Jinyi Duan ◽  
Reed Ressler ◽  
Alexander B. Johnson ◽  
...  
Keyword(s):  
Ventral Tegmental Area ◽  
Cell Types ◽  
Afferent Inputs ◽  
Ventral Tegmental

scholarly journals Facilitation of cutaneous inputs during the planning phase of gait initiation

2015 ◽  
Vol 114 (1) ◽  
pp. 301-308 ◽  
Author(s):  
Laurence Mouchnino ◽  
Aurélie Fontan ◽  
Christophe Tandonnet ◽  
Joy Perrier ◽  
Anahid H. Saradjian ◽  
...  
Keyword(s):  
Evoked Potential ◽  
Gait Initiation ◽  
Motor Execution ◽  
Movement Execution ◽  
Movement Initiation ◽  
Somatosensory Stimulation ◽  
Planning Phase ◽  
Step Initiation ◽  
Afferent Information ◽  
Afferent Inputs

It has been shown that during the planning of a voluntary movement the transmission of cutaneous afferent inputs to the somatosensory cortex is attenuated shortly before the motor output as well as during movement execution. However, it is not known whether the sensory suppression observed during the planning phase (i.e., before any movement execution) is a systemic phenomenon or whether it is dependent on movement context. For example, movements such as step initiation are controlled based on information received from cutaneous receptors in the feet. Because afferent information emerging from these receptors is critical for movement initiation, we hypothesized that suppression of these inputs may not occur during the planning phase prior to gait initiation. To examine this hypothesis we measured the cortical response to somatosensory stimulation during the planning phase of step initiation and during movement execution. Sensitivity to cutaneous stimulation was assessed by measuring the amplitude of the cortical somatosensory-evoked potential (SEP, over the Cz electrode) following electrical stimulations of the plantar sole of one foot. Two stimulations were provided during the planning phase of a step movement and two stimulations during movement execution. It was found that the P50-N80 SEP was facilitated in the early planning phase (−700 ms before motor execution) compared with when participants remained still (control standing task). This mechanism might contribute to an enhanced perception of cutaneous input leading to a more accurate setting of the forces to be exerted onto the ground to shift the body's weight toward the supporting side prior to foot-off.

Small-caliber afferent inputs produce a heterosynaptic facilitation of the synaptic responses evoked by primary afferent A-fibers in the neonatal rat spinal cord in vitro

1993 ◽  
Vol 69 (6) ◽  
pp. 2116-2128 ◽  
Author(s):  
S. W. Thompson ◽  
C. J. Woolf ◽  
L. G. Sivilotti
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Fiber Strength ◽  
Conditioning Stimulus ◽  
Neonatal Rat ◽  
Primary Afferent ◽  
Synaptic Potentials ◽  
C Fiber ◽  
Afferent Inputs

1. The effect of brief primary afferent inputs on the amplitude and duration of the synaptic potentials evoked in ventral horn (VH) neurons by the activation of other unconditioned primary afferents was studied by current-clamp intracellular recording in the neonatal rat hemisected spinal cord in vitro. Low-frequency (1 Hz) trains of stimulation were applied to a lumbar dorsal root (Conditioning root) for 20-30 s. Test excitatory synaptic potentials (EPSPs) were evoked by single electrical shocks applied to an adjacent Test dorsal root. 2. Test and Conditioning inputs were generated at stimulation strengths sufficient to activate A beta-, A delta- and C-afferent fibers successively. At A delta- and C-fiber strength the EPSPs lasted for 4-6 s, and, during the repetitive Conditioning inputs, these summated to produce a progressively incrementing cumulative depolarization that slowly decayed back to the control Vm over tens of seconds. 3. Dorsal root conditioning produced heterosynaptic facilitation, defined as an enhancement of Test EPSPs above their DC matched controls, in 7 out of 20 neurons. To facilitate the unconditioned afferent input, the intensity of conditioning stimulation had to exceed the threshold for the activation of thin myelinated (A delta) afferents: conditioning at A beta-fiber strength had no effect, whereas A delta- and C-fiber strength conditioning were equally effective. 4. Heterosynaptic facilitation of only A beta- or A delta-fiber-evoked Test EPSPs was observed, no enhancement of C-fiber strength Test EPSPs could be demonstrated. The facilitation manifested as increases in the EPSP peak amplitude, area or the number of action potentials evoked. 5. Conditioning trials that produced heterosynaptic facilitation generated cumulative depolarizations larger than those produced by ineffective conditioning trials (9.1 +/- 3.1 vs. 3.3 +/- 0.5 mV after 20 s conditioning at resting Vm, mean +/- SE, n = 6 and 13, respectively; P < 0.05). The slope of the Vm trajectory during the summation of the conditioning EPSPs was higher in trials resulting in heterosynaptic facilitation, at 0.31 +/- 0.10 mV/s in neurons with heterosynaptic facilitation and 0.06 +/- 0.02 mV/s in cells without heterosynaptic facilitation (P < 0.05). 5. Four of the 20 VH neurons in our sample responded to A delta/C-fiber conditioning with action-potential windup: all 4 also displayed heterosynaptic facilitation. 6. Heterosynaptic facilitation decayed after the completion of the conditioning stimulus with a time course that was parallel to but not superimposable on that of the slow Vm depolarization evoked by the conditioning.(ABSTRACT TRUNCATED AT 400 WORDS)

Interaction between chemoreceptor and stretch receptor inputs at medullary respiratory neurons

1994 ◽  
Vol 266 (6) ◽  
pp. R1951-R1961 ◽  
Author(s):  
J. Bajic ◽  
E. J. Zuperku ◽  
M. Tonkovic-Capin ◽  
F. A. Hopp
Keyword(s):  
Time Course ◽  
Afferent Input ◽  
Respiratory Neurons ◽  
Neuronal Responses ◽  
Additive Interaction ◽  
Dorsal Respiratory Group ◽  
Afferent Inputs ◽  
Discharge Patterns ◽  
Carotid Body Chemoreceptors ◽  
Common Carotid Arteries

The interaction between afferent inputs from carotid body chemoreceptors (CCRs) and from slowly adapting pulmonary stretch receptors (PSRs) on the discharge patterns of medullary inspiratory (I) and expiratory (E) neurons was characterized in thiopental sodium-anesthetized, paralyzed, ventilated dogs. A cycle-triggered ventilator was used to produce control and test pulmonary afferent input patterns. The CCRs were stimulated by phase-synchronized bolus injections of CO2-saturated saline into the common carotid arteries. Only those neurons whose discharge time course was altered by both inflation and CCR activation were studied. The dorsal respiratory group (DRG) I inflation-insensitive neurons were also included. Cycle-triggered histograms of unit activity were obtained for the neuronal responses to inflation, CO2 bolus, and their combination, as well as for the spontaneous control condition. Linearity of the interaction was tested by comparing the sum of the net individual responses to the net response of the combined afferent inputs. The results suggest that a linear (additive) interaction between CCR and PSR inputs exists for the DRG I inflation-sensitive neurons, the ventral respiratory group (VRG) I decrementing, and caudal VRG E augmenting neurons, while a nonadditive interaction exists for caudal VRG E decrementing bulbospinal neurons. The implications of these findings are discussed.

Organization of the primate face motor cortex as revealed by intracortical microstimulation and electrophysiological identification of afferent inputs and corticobulbar projections

1988 ◽  
Vol 59 (3) ◽  
pp. 796-818 ◽  
Author(s):  
C. S. Huang ◽  
M. A. Sirisko ◽  
H. Hiraba ◽  
G. M. Murray ◽  
B. J. Sessle
Keyword(s):  
Motor Cortex ◽  
Single Neuron ◽  
Primary Motor Cortex ◽  
General Pattern ◽  
Emg Activity ◽  
Projection Neurons ◽  
Intracortical Microstimulation ◽  
Facial Musculature ◽  
The Face ◽  
Afferent Inputs

1. The technique of intracortical microstimulation (ICMS), supplemented by single-neuron recording, was used to carry out an extensive mapping of the face primary motor cortex. The ICMS study involved a total of 969 microelectrode penetrations carried out in 10 unanesthetized monkeys (Macaca fascicularis). 2. Monitoring of ICMS-evoked movements and associated electromyographic (EMG) activity revealed a general pattern of motor cortical organization. This was characterized by a representation of the facial musculature, which partially enclosed and overlapped the rostral, medial, and caudal borders of the more laterally located cortical regions representing the jaw and tongue musculatures. Responses were evoked at ICMS thresholds as low as 1 microA, and the latency of the suprathreshold EMG responses ranged from 10 to 45 ms. 3. Although contralateral movements predominated, a representation of ipsilateral movements was found, which was much more extensive than previously reported and which was intermingled with the contralateral representations in the anterior face motor cortex. 4. In examining the fine organizational pattern of the representations, we found clear evidence for multiple representation of a particular muscle, thus supporting other investigations of the motor cortex, which indicate that multiple, yet discrete, efferent microzones represent an essential organizational principle of the motor cortex. 5. The close interrelationship of the representations of all three muscle groups, as well as the presence of a considerable ipsilateral representation, may allow for the necessary integration of unilateral or bilateral activities of the numerous face, jaw, and tongue muscles, which is a feature of many of the movement patterns in which these various muscles participate. 6. In six of these same animals, plus an additional two animals, single-neuron recordings were made in the motor and adjacent sensory cortices in the anesthetized state. These neurons were electrophysiologically identified as corticobulbar projection neurons or as nonprojection neurons responsive to superficial or deep orofacial afferent inputs. The rostral, medial, lateral, and caudal borders of the face motor cortex were delineated with greater definition by ICMS and these electrophysiological procedures than by cytoarchitectonic features alone. We noted that there was an approximate fit in area 4 between the extent of projection neurons and field potentials anti-dromically evoked from the brain stem and the extent of positive ICMS sites.(ABSTRACT TRUNCATED AT 400 WORDS)

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