scholarly journals Respiratory response to activation or disinhibition of the dorsal periaqueductal gray in rats

2003 ◽  
Vol 94 (3) ◽  
pp. 913-922 ◽  
Author(s):  
Linda F. Hayward ◽  
Camille L. Swartz ◽  
Paul W. Davenport
Keyword(s):  
Defense Response ◽  
Defense Responses ◽  
Neural Substrates ◽  
Periaqueductal Gray ◽  
Similar Response ◽  
Respiratory Change ◽  
Behavioral Defense ◽  
Expiration Time ◽  
Spontaneously Breathing ◽  
Dose Dependent

The neural substrates mediating autonomic components of the behavioral defense response have been shown to reside in the periaqueductal gray (PAG). The cardiovascular components of the behavioral defense response have been well described and are tonically suppressed by GABAergic input. The ventilatory response associated with disinhibition of the dorsal PAG (dPAG) neurons is unknown. In urethane-anesthetized, spontaneously breathing rats, electrical stimulation of the dPAG was shown to decrease the expiration time and increase respiratory frequency, with no change in time of inspiration. Baseline and the change in diaphragm electromyograph also increased, resulting in an increase in neural minute activity. Microinjection of bicuculline methobromide, a GABAA-receptor antagonist, into the dPAG produced a similar response, which was dose dependent. Disinhibition of the dPAG also produced a decrease in inspiration time. These results suggest that GABAA-mediated suppression of dPAG neurons plays a role in the respiratory component of behavioral defense responses. The respiratory change is due in part to a change in brain stem respiratory timing and phasic inspiratory output. In addition, there is an increase in tonic diaphragm activity.

Parabrachial neurons mediate dorsal periaqueductal gray evoked respiratory responses in the rat

2004 ◽  
Vol 96 (3) ◽  
pp. 1146-1154 ◽  
Author(s):  
Linda F. Hayward ◽  
Mabelin Castellanos ◽  
Paul W. Davenport
Keyword(s):  
Heart Rate ◽  
Significant Role ◽  
Defense Response ◽  
Pressor Response ◽  
Defense Responses ◽  
Periaqueductal Gray ◽  
Parabrachial Nucleus ◽  
Ventrolateral Medulla ◽  
Descending Pathways ◽  
Behavioral Defense

The neural substrates mediating autonomic components of the behavioral defense response reside in the periaqueductal gray (PAG). The cardiovascular components of the defense response evoked from the dorsal PAG (DPAG) have been well described and are dependent, in part, on the integrity of neurons in the region of the parabrachial nucleus as well as the rostral ventrolateral medulla. Descending pathways mediating the ventilatory response associated with activation of DPAG neurons are unknown. The present study was undertaken to test the hypothesis that parabrachial area neurons are also involved in mediating the respiratory response to DPAG stimulation. In urethane-anesthetized, spontaneously breathing rats, electrical stimulation of the DPAG significantly increased respiratory rate, arterial pressure, and heart rate. Changes in respiratory frequency were associated with significant decreases in inspiratory and expiratory durations. After bilateral inhibition of neurons in the lateral parabrachial nucleus (LPBN) region with 5 mM muscimol ( n = 6), DPAG-evoked increases in respiration and heart rate were attenuated by 90 ± 6 and 72 ± 13%, respectively. The pressor response evoked by DPAG stimulation, however, was attenuated by only 57 ± 6%. Bilateral blockade of glutamate receptors with 20 mM kynurenic acid ( n = 6) in the LPBN also markedly attenuated DPAG-evoked increases in respiration and heart rate (65 ± 15 and 53 ± 9% reduction, respectively) but only modestly changed the DPAG-evoked pressor response (34 ± 16% reduction). These results demonstrate that LPBN neurons play a significant role in the DPAG-mediated respiratory component of behavioral defense responses. This finding supports previous work demonstrating that the dorsolateral pons plays a significant role in mediating most physiological adjustments associated with activation of the DPAG.

scholarly journals Deletion of the SACPD-C Locus Alters the Symbiotic Relationship Between Bradyrhizobium japonicum USDA110 and Soybean, Resulting in Elicitation of Plant Defense Response and Nodulation Defects

2016 ◽  
Vol 29 (11) ◽  
pp. 862-877 ◽  
Author(s):  
Hari B. Krishnan ◽  
Alaa A. Alaswad ◽  
Nathan W. Oehrle ◽  
Jason D. Gillman
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
Acyl Carrier Protein ◽  
Defense Responses ◽  
Nodule Development ◽  
Plant Defense Response ◽  
Wild Type ◽  
Two Dimensional Gel Electrophoresis ◽  
Symbiotic Associations ◽  
Soybean Nodule

Legumes form symbiotic associations with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia-encoded nitrogenase facilitates the conversion of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of stearoyl-acyl carrier protein desaturase isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen-fixing nodules. In-depth cytological investigation of nodule development in sacpd-c mutant lines M25 and MM106 revealed gross anatomical alteration in the sacpd-c mutants. Transmission electron microscopy observations revealed ultrastructural alterations in the sacpd-c mutants that are typically associated with plant defense response to pathogens. In nodules of two sacpd-c mutants, the combined jasmonic acid (JA) species (JA and the isoleucine conjugate of JA) were found to be reduced and 12-oxophytodienoic acid (OPDA) levels were significantly higher relative to wild-type lines. Salicylic acid levels were not significantly different between genotypes, which is divergent from previous studies of sacpd mutant studies on vegetative tissues. Soybean nodule phytohormone profiles were very divergent from those of roots, and root profiles were found to be almost identical between mutant and wild-type genotypes. The activities of antioxidant enzymes, ascorbate peroxidase, and superoxide dismutase were also found to be higher in nodules of sacpd-c mutants. PR-1 gene expression was extremely elevated in M25 and MM106, while the expression of nitrogenase was significantly reduced in these sacpd-c mutants, compared with the parent ‘Bay’. Two-dimensional gel electrophoresis and matrix-assisted laser desorption-ionization time of flight mass spectrometry analyses confirmed sacpd-c mutants also accumulated higher amounts of pathogenesis-related proteins in the nodules. Our study establishes a major role for SACPD-C activity as essential for proper maintenance of soybean nodule morphology and physiology and indicates that OPDA signaling is likely to be involved in attenuation of nodule biotic defense responses.

scholarly journals Transcriptomic Analysis of Arabidopsis Seedlings in Response to an Agrobacterium-Mediated Transformation Process

2018 ◽  
Vol 31 (4) ◽  
pp. 445-459 ◽  
Author(s):  
Kaixuan Duan ◽  
Christopher J. Willig ◽  
Joann R. De Tar ◽  
William G. Spollen ◽  
Zhanyuan J. Zhang
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Defense Response ◽  
Time Course ◽  
Basic Research ◽  
Defense Responses ◽  
Transformation Process ◽  
Host Responses ◽  
Nucleic Acid Metabolism ◽  
Agrobacterium Strain ◽  
Agrobacterium Mediated Transformation

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease. This pathogen is capable of transferring the T-DNA from its Ti plasmid to the host cell and, then, integrating it into the host genome. To date, this genetic transformation ability has been harnessed as the dominant technology to produce genetically modified plants for both basic research and crop biotechnological applications. However, little is known about the interaction between Agrobacterium tumefaciens and host plants, especially the host responses to Agrobacterium infection and its associated factors. We employed RNA-seq to follow the time course of gene expression in Arabidopsis seedlings infected with either an avirulent or a virulent Agrobacterium strain. Gene Ontology analysis indicated many biological processes were involved in the Agrobacterium-mediated transformation process, including hormone signaling, defense response, cellular biosynthesis, and nucleic acid metabolism. RNAseq and quantitative reverse transcription-polymerase chain reaction results indicated that expression of genes involved in host plant growth and development were repressed but those involved in defense response were induced by Agrobacterium tumefaciens. Further analysis of the responses of transgenic Arabidopsis lines constitutively expressing either the VirE2 or VirE3 protein suggested Vir proteins act to enhance plant defense responses in addition to their known roles facilitating T-DNA transformation.

The defense response of Caenorhabditis elegans to Cutibacterium acnes SK137 via the TIR-1-p38 MAPK signaling pathway

2021 ◽  
Author(s):  
Ayano Tsuru ◽  
Yumi Hamazaki ◽  
Shuta Tomida ◽  
Mohammad Shaokat Ali ◽  
Eriko Kage-Nakadai
Keyword(s):  
Caenorhabditis Elegans ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Defense Response ◽  
Mapk Pathway ◽  
Defense Responses ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Healthy Skin ◽  
Cutibacterium Acnes

Abstract Cutibacterium acnes plays roles in both acne disease and healthy skin ecosystem. We observed that mutations in the tir-1/SARM1 and p38 MAPK cascade genes significantly shortened Caenorhabditis elegans lifespan upon Cutibacterium acnes SK137 infection. Antimicrobial molecules were induced by SK137 in a TIR-1-dependent manner. These results suggest that defense responses against SK137 involve the TIR-1-p38 MAPK pathway in Caenorhabditis elegans.

scholarly journals A Faster and a Stronger Defense Response: One of the Key Elements in Grapevine Explaining Its Lower Level of Susceptibility to Esca?

2013 ◽  
Vol 103 (10) ◽  
pp. 1028-1034 ◽  
Author(s):  
Carole Lambert ◽  
Ian Li Kim Khiook ◽  
Sylvia Lucas ◽  
Nadège Télef-Micouleau ◽  
Jean-Michel Mérillon ◽  
...  
Keyword(s):  
Defense Response ◽  
Defense Mechanisms ◽  
Defense Responses ◽  
Cabernet Sauvignon ◽  
Susceptible Cultivar ◽  
Pathogenesis Related ◽  
Leaf Level ◽  
Plant Pathogen Interaction ◽  
Related Proteins ◽  
Stilbene Compounds

Wood diseases like Esca are among the most damaging afflictions in grapevine. The defense mechanisms in this plant–pathogen interaction are not well understood. As some grapevine cultivars have been observed to be less susceptible to Esca than others, understanding the factors involved in this potentially stronger defense response can be of great interest. To lift part of this veil, we elicited Vitis vinifera plants of two cultivars less susceptible to Esca (‘Merlot’ and ‘Carignan’) and of one susceptible cultivar (‘Cabernet Sauvignon’), and monitored their defense responses at the leaf level. Our model of elicitation consisted in grapevine cuttings absorbing a culture filtrate of one causal agent of Esca, Phaemoniella chlamydospora. This model might reflect the early events occurring in Esca-affected grapevines. The two least susceptible cultivars showed an earlier and stronger defense response than the susceptible one, particularly with regard to induction of the PAL and STS genes, and a higher accumulation of stilbene compounds and some pathogenesis-related proteins.

scholarly journals Using physiological signals to predict temporal defense responses: a multi-modality analysis

2020 ◽  
Author(s):  
Tae-jun Choi ◽  
Honggu Lee
Keyword(s):  
Defense Response ◽  
Defense Responses ◽  
Physiological Signals ◽  
Classification Model ◽  
Post Traumatic Stress ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Novel Approach ◽  
Data Driven Approach ◽  
Response Classification

AbstractDefense responses are a highly conserved behavioral response set across species. Defense responses motivate organisms to detect and react to threats and potential danger as a precursor to anxiety. Accurate measurement of temporal defense responses is important for understanding clinical anxiety and mood disorders, such as post-traumatic stress disorder, obsessive compulsive disorder, and generalized anxiety disorder. Within these conditions, anxiety is defined as a state of prolonged defense response elicitation to a threat that is ambiguous or unspecific. In this study, we aimed to develop a data-driven approach to capture temporal defense response elicitation through a multi-modality data analysis of physiological signals, including electroencephalogram (EEG), electrocardiogram (ECG), and eye-tracking information. A fear conditioning paradigm was adopted to develop a defense response classification model. From a classification model based on 42 feature sets, a higher order crossing feature set-based model was chosen for further analysis with cross-validation loss of 0.0462 (SEM: 0.0077). To validate our model, we compared predicted defense response occurrence ratios from a comprehensive situation that generates defense responses by watching movie clips with fear awareness and threat existence predictability, which have been reported to correlate with defense response elicitation in previous studies. We observed that defense response occurrence ratios are correlated with threat existence predictability, but not with fear awareness. These results are similar to those of previous studies using comprehensive situations. Our study provides insight into measurement of temporal defense responses via a novel approach, which can improve understanding of anxiety and related clinical disorders for neurobiological and clinical researchers.

scholarly journals Chitinase Gene Positively Regulates Hypersensitive and Defense Responses of Pepper to Colletotrichum acutatum Infection

2020 ◽  
Vol 21 (18) ◽  
pp. 6624 ◽  
Author(s):  
Muhammad Ali ◽  
Quan-Hui Li ◽  
Tao Zou ◽  
Ai-Min Wei ◽  
Ganbat Gombojab ◽  
...  
Keyword(s):  
Defense Response ◽  
Defense Responses ◽  
Chitinase Gene ◽  
Colletotrichum Acutatum ◽  
Basal Resistance ◽  
Chitin Binding Domain ◽  
Pepper Leaves ◽  
Defense Response Genes ◽  
Chitinase Genes ◽  
Pepper Plants

Anthracnose caused by Colletotrichum acutatum is one of the most devastating fungal diseases of pepper (Capsicum annuum L.). The utilization of chitin-binding proteins or chitinase genes is the best option to control this disease. A chitin-binding domain (CBD) has been shown to be crucial for the innate immunity of plants and activates the hypersensitive response (HR). The CaChiIII7 chitinase gene has been identified and isolated from pepper plants. CaChiIII7 has repeated CBDs that encode a chitinase enzyme that is transcriptionally stimulated by C. acutatum infection. The knockdown of CaChiIII7 in pepper plants confers increased hypersensitivity to C. acutatum, resulting in its proliferation in infected leaves and an attenuation of the defense response genes CaPR1, CaPR5, and SAR8.2 in the CaChiIII7-silenced pepper plants. Additionally, H2O2 accumulation, conductivity, proline biosynthesis, and root activity were distinctly reduced in CaChiIII7-silenced plants. Subcellular localization analyses indicated that the CaChiIII7 protein is located in the plasma membrane and cytoplasm of plant cells. The transient expression of CaChiIII7 increases the basal resistance to C. acutatum by significantly expressing several defense response genes and the HR in pepper leaves, accompanied by an induction of H2O2 biosynthesis. These findings demonstrate that CaChiIII7 plays a prominent role in plant defense in response to pathogen infection.

Effects of almitrine on genioglossal and diaphragmatic electromyograms

1986 ◽  
Vol 61 (6) ◽  
pp. 2122-2128 ◽  
Author(s):  
D. E. Weese-Mayer ◽  
R. T. Brouillette ◽  
L. M. Klemka ◽  
C. E. Hunt
Keyword(s):  
Slow Wave Sleep ◽  
Minute Ventilation ◽  
Upper Airway ◽  
Respiratory Drive ◽  
Peripheral Chemoreceptor ◽  
Obstructive Sleep ◽  
Adult Cats ◽  
Alpha Chloralose ◽  
Spontaneously Breathing ◽  
Dose Dependent

We previously demonstrated dose-dependent increases in both hypoglossal and phrenic electroneurograms after almitrine in anesthetized, paralyzed, and vagotomized cats. We have now investigated the effect of this peripheral chemoreceptor stimulant on diaphragmatic and genioglossal (GG, an upper airway-maintaining muscle) electromyograms in five unanesthetized, chronically instrumented, spontaneously breathing adult cats during slow-wave sleep. In 12 studies almitrine doses of 1.0–6.0 mg/kg increased inspired minute ventilation (VI), frequency (f), and tidal volume (VT) and decreased expiratory time (TE). However, almitrine doses as high as 6.0 mg/kg failed to augment phasic inspiratory GG activity. To determine why almitrine induced phasic inspiratory upper airway activity in anesthetized, vagotomized cats but not in sleeping cats, additional studies were performed. In four dose-response studies in three pentobarbital-anesthetized cats, almitrine, 1.0–6.0 mg/kg, did not produce phasic inspiratory GG activity. Almitrine did induce phasic inspiratory GG activity in two of three studies in three vagotomized, tracheostomized, alpha-chloralose-urethan-anesthetized cats. These results suggest that almitrine would not be useful in obstructive sleep apnea, yet because almitrine markedly increased VI, f, and VT and decreased TE in unanesthetized sleeping cats the drug may be effective in patients who lack normal central neural respiratory drive, such as the preterm infant.

Ventilatory CO2-induced optical activity changes of cat ventral medullary surface

1993 ◽  
Vol 265 (3) ◽  
pp. R494-R503 ◽  
Author(s):  
X. W. Dong ◽  
D. Gozal ◽  
D. M. Rector ◽  
R. M. Harper
Keyword(s):  
Baseline Period ◽  
Optical Recording ◽  
Video Frames ◽  
Topographical Distribution ◽  
Light Reflectance ◽  
Suprasylvian Cortex ◽  
Ventral Medullary Surface ◽  
Adult Cats ◽  
Spontaneously Breathing ◽  
Dose Dependent

We examined neuronal activation of the ventral medullary surface (VMS) during hypercapnic challenges using optical recording procedures. With a coherent imaging probe, we assessed reflected 700-nm light from 18 VMS sites in 11 spontaneously breathing adult cats and from the suprasylvian cortex in two cats. Video frames were acquired during a baseline period, hypercapnic (3, 5, and 10% CO2 in O2) exposure, and recovery. Hypercapnic exposure elicited overall reflectance changes in all VMS sites, but no changes in the suprasylvian cortex. Light reflectance changes, suggesting altered neuronal activity, were reproducible, occurred as early as 30 s after CO2 exposure, and were dose dependent. The changes persisted approximately 20-25 min beyond the stimulus, but respiratory responses consistently recovered within 2-3 min. Although more rostral VMS sites tended to be associated with decreased activity and caudal regions with increased excitation, no uniform topographical organization was apparent across animals. The variability in VMS optical reflectance patterns across animals during CO2 stimulation may reflect the heterogeneous topographical distribution of responsive neurons in the structure.

scholarly journals Signaling Crosstalk between Salicylic Acid and Ethylene/Jasmonate in Plant Defense: Do We Understand What They Are Whispering?

2019 ◽  
Vol 20 (3) ◽  
pp. 671 ◽  
Author(s):  
Ning Li ◽  
Xiao Han ◽  
Dan Feng ◽  
Deyi Yuan ◽  
Li-Jun Huang
Keyword(s):  
Salicylic Acid ◽  
Signaling Pathways ◽  
Pseudomonas Syringae ◽  
Defense Response ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Host Cells ◽  
Defense Gene Expression ◽  
Signaling Crosstalk

During their lifetime, plants encounter numerous biotic and abiotic stresses with diverse modes of attack. Phytohormones, including salicylic acid (SA), ethylene (ET), jasmonate (JA), abscisic acid (ABA), auxin (AUX), brassinosteroid (BR), gibberellic acid (GA), cytokinin (CK) and the recently identified strigolactones (SLs), orchestrate effective defense responses by activating defense gene expression. Genetic analysis of the model plant Arabidopsis thaliana has advanced our understanding of the function of these hormones. The SA- and ET/JA-mediated signaling pathways were thought to be the backbone of plant immune responses against biotic invaders, whereas ABA, auxin, BR, GA, CK and SL were considered to be involved in the plant immune response through modulating the SA-ET/JA signaling pathways. In general, the SA-mediated defense response plays a central role in local and systemic-acquired resistance (SAR) against biotrophic pathogens, such as Pseudomonas syringae, which colonize between the host cells by producing nutrient-absorbing structures while keeping the host alive. The ET/JA-mediated response contributes to the defense against necrotrophic pathogens, such as Botrytis cinerea, which invade and kill hosts to extract their nutrients. Increasing evidence indicates that the SA- and ET/JA-mediated defense response pathways are mutually antagonistic.

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