scholarly journals The role of neuronal excitation and inhibition in the pre-Bötzinger complex on the cough reflex in the cat

Author(s):  
Tabitha Y Shen ◽  
Ivan Poliacek ◽  
Melanie J. Rose ◽  
Matthew Nicholas Musselwhite ◽  
Zuzana Kotmanova ◽  
...  

Brainstem respiratory neuronal network significantly contributes to cough motor pattern generation. Neuronal populations in the pre-Bötzinger complex (PreBötC) represent a substantial component for respiratory rhythmogenesis. We studied the role of PreBötC neuronal excitation and inhibition on mechanically induced tracheobronchial cough in 15 spontaneously breathing, pentobarbital anesthetized adult cats (35 mg/kg i.v. initially). Neuronal excitation by unilateral microinjection of glutamate analog D,L-homocysteic acid resulted in mild reduction of cough abdominal electromyogram (EMG) amplitudes and very limited temporal changes of cough compared to effects on breathing (very high respiratory rate, high amplitude inspiratory bursts with a short inspiratory phase and tonic inspiratory motor component). Mean arterial blood pressure temporarily decreased. Blocking glutamate related neuronal excitation by bilateral microinjections of non-specific glutamate receptor antagonist kynurenic acid reduced cough inspiratory and expiratory EMG amplitude and shortened most cough temporal characteristics similarly to breathing temporal characteristics. Respiratory rate decreased and blood pressure temporarily increased. Limiting active neuronal inhibition by unilateral and bilateral microinjections of GABAA receptor antagonist gabazine resulted in lower cough number, reduced expiratory cough efforts, and prolongation of cough temporal features and breathing phases (with lower respiratory rate). The PreBötC is important for cough motor pattern generation. Excitatory glutamatergic neurotransmission in the PreBötC is involved in control of cough intensity and patterning. GABAA receptor related inhibition in the PreBötC strongly affects breathing and coughing phase durations in the same manner, as well as cough expiratory efforts. In conclusion, differences in effects on cough and breathing are consistent with separate control of these behaviors.

1996 ◽  
Vol 317 (2-3) ◽  
pp. 301-307 ◽  
Author(s):  
Tahir Tellioǧlu ◽  
Serap Akin ◽  
Uǧur Özkutlu ◽  
Şule Oktay ◽  
Filiz Onat

2015 ◽  
Vol 114 (5) ◽  
pp. 2649-2660 ◽  
Author(s):  
Pedro F. Jacob ◽  
Berthold Hedwig

The cercal system of crickets detects low-frequency air currents produced by approaching predators and self-generated air currents during singing, which may provide sensory feedback to the singing motor network. We analyzed the effect of cercal stimulation on singing motor pattern generation to reveal the response of a singing interneuron to predator-like signals and to elucidate the possible role of self-generated air currents during singing. In fictive singing males, we recorded an interneuron of the singing network while applying air currents to the cerci; additionally, we analyzed the effect of abolishing the cercal system in freely singing males. In fictively singing crickets, the effect of short air stimuli is either to terminate prematurely or to lengthen the interchirp interval, depending on their phase in the chirp cycle. Within our stimulation paradigm, air stimuli of different velocities and durations always elicited an inhibitory postsynaptic potential in the singing interneuron. Current injection in the singing interneuron elicited singing motor activity, even during the air current-evoked inhibitory input from the cercal pathway. The disruptive effects of air stimuli on the fictive singing pattern and the inhibitory response of the singing interneuron point toward the cercal system being involved in initiating avoidance responses in singing crickets, according to the established role of cerci in a predator escape pathway. After abolishing the activity of the cercal system, the timing of natural singing activity was not significantly altered. Our study provides no evidence that self-generated cercal sensory activity has a feedback function for singing motor pattern generation.


1996 ◽  
Vol 76 (3) ◽  
pp. 687-717 ◽  
Author(s):  
E. Marder ◽  
R. L. Calabrese

Rhythmic movements are produced by central pattern-generating networks whose output is shaped by sensory and neuromodulatory inputs to allow the animal to adapt its movements to changing needs. This review discusses cellular, circuit, and computational analyses of the mechanisms underlying the generation of rhythmic movements in both invertebrate and vertebrate nervous systems. Attention is paid to exploring the mechanisms by which synaptic and cellular processes interact to play specific roles in shaping motor patterns and, consequently, movement.


2000 ◽  
Vol 20 (17) ◽  
pp. 6619-6630 ◽  
Author(s):  
Deborah J. Baro ◽  
Amir Ayali ◽  
Lauren French ◽  
Nathaniel L. Scholz ◽  
Jana Labenia ◽  
...  

2002 ◽  
Vol 103 (s2002) ◽  
pp. 380S-384S ◽  
Author(s):  
Isabelle BROCHU ◽  
Julie LABONTÉ ◽  
Ghassan BKAILY ◽  
Pedro D'ORLÉANS-JUSTE

Mice with disruption of the kinin B2 receptor (B2KO mice) are sensitive to salt-rich diets, which causes hypertension. The aim of the study was to assess the role of endothelin-1 (ET-1) and angiotensin-II in hypertensive B2KO mice on a salt-rich diet. We also wanted to verify if there is an upregulation of the mRNA expression of the precursors or receptors for these hormones. Two groups of B2KO mice (20–25g) were investigated. The first group received an 8% NaCl diet with 1% NaCl in drinking water (HS) and the second was fed with normal food with tap water (NS). The antagonists tested were the ETA receptor antagonist BQ-123 (1 and 5mg/kg), the ETB receptor antagonist BQ-788 (0.25 and 1mg/kg), the angiotensin receptor type 1 antagonist losartan (10mg/kg) and the angiotensin-converting enzyme inhibitor captopril (3mg/kg). These were injected intraperitoneally 30min prior to blood pressure measurement by the tail-cuff method. We also studied the level of expression of preproET-1, ET-1 receptors, angiotensinogen and angiotensin receptors by RNA extraction from the heart and kidneys of these mice followed by reverse transcriptase (RT)-PCR. B2KO mice (HS) were hypertensive after 8 weeks compared with B2KO mice on normal diet (HS, 93.4±1.5mmHg, n = 7; NS, 61.4±2.7mmHg, n = 7). In the HS group, the mean arterial blood pressure was significantly reduced by BQ-123 (5mg/kg) to 61.9±1.8mmHg (n = 7), by BQ-788 (1mg/kg) to 58.8±2.6mmHg (n = 6), by losartan (10mg/kg) to 73.2±1.7mmHg (n = 8) and by captopril (3mg/kg) to 86.0±2.3mmHg (n = 8). The expression studied by RT-PCR did not show any difference (either in precursors or receptors expression) between hypertensive and normal mice. The four antagonists used seemed to reverse the hypertension. These results suggest that ET-1 and angiotensin-II are probably involved in the mechanism that leads to hypertension since the effect of these hormones is probably not compensated by kinins in B2KO mice. Further studies are necessary to understand the implication of the cross-talk between these hormones in the hypertensive state.


Sign in / Sign up

Export Citation Format

Share Document