Amygdala mediates respiratory responses to sudden arousing stimuli and to restraint stress in rats

2014 ◽  
Vol 306 (12) ◽  
pp. R951-R959 ◽  
Author(s):  
Evgeny Bondarenko ◽  
Deborah M. Hodgson ◽  
Eugene Nalivaiko
Keyword(s):  
Respiratory Rate ◽  
Restraint Stress ◽  
Animal Studies ◽  
Whole Body ◽  
Acoustic Stimuli ◽  
Respiratory Parameters ◽  
Male Wistar Rats ◽  
The Mean ◽  
Whole Body Plethysmography ◽  
Respiratory Responses

Both human and animal studies have demonstrated that respiratory parameters change in response to presentation of alerting stimuli, as well as during stress, yet central neuronal pathways that mediate such responses remain unknown. The aim of our study was to investigate the involvement of the amygdala in mediating respiratory responses to stressors of various intensities and duration. Adult male Wistar rats ( n = 8) received microinjections of GABAA agonist muscimol or saline into the amygdala bilaterally and were subjected to a respiratory recording using whole body plethysmography. Presentation of acoustic stimuli (500-ms white noise, 40–90 dB) caused transient responses in respiratory rate that were proportional to the stimulus intensity, ranging from +13 ± 9 cpm to +276 ± 67 cpm for 40- and 90-dB stimuli, respectively. Inhibition of the amygdala significantly suppressed respiratory rate responses to the high-intensity stimuli (70–90 dB). Submitting rats to the restraint stress significantly elevated the mean respiratory rate (+72 ± 8 cpm) and the dominant respiratory rate (+51 ± 12 cpm), as well as the fraction of high-frequency respiratory rate (+10 ± 3%). Inhibition of the amygdala by muscimol significantly suppressed these responses. We conclude that the amygdala is one of the key structures that are essential for expression of respiratory responses to stressful or alerting stimuli in rats.

Blockade of the dorsomedial hypothalamus and the perifornical area inhibits respiratory responses to arousing and stressful stimuli

2015 ◽  
Vol 308 (10) ◽  
pp. R816-R822 ◽  
Author(s):  
Evgeny Bondarenko ◽  
Mirza I. Beig ◽  
Deborah M. Hodgson ◽  
Valdir A. Braga ◽  
Eugene Nalivaiko
Keyword(s):  
Respiratory Rate ◽  
Light Stimulus ◽  
Whole Body ◽  
Dorsomedial Hypothalamus ◽  
Acoustic Stimuli ◽  
Male Wistar Rats ◽  
Acclimatization Period ◽  
Environment Stress ◽  
Conscious Animals ◽  
Respiratory Responses

The dorsomedial hypothalamus (DMH) and the perifornical area (DMH/PeF) is one of the key regions of central autonomic processing. Previous studies have established that this region contains neurons that may be involved in respiratory processing; however, this has never been tested in conscious animals. The aim of our study was to investigate the involvement of the DMH/PeF area in mediating respiratory responses to stressors of various intensities and duration. Adult male Wistar rats ( n = 8) received microinjections of GABAA agonist muscimol or saline into the DMH/PeF bilaterally and were subjected to a respiratory recording using whole body plethysmography. Presentation of acoustic stimuli (500-ms white noise) evoked transient responses in respiratory rate, proportional to the stimulus intensity, ranging from +44 ± 27 to +329 ± 31 cycles/min (cpm). Blockade of the DMH/PeF almost completely abolished respiratory rate and tidal volume responses to the 40- to 70-dB stimuli and also significantly attenuated responses to the 80- to 90-dB stimuli. Also, it significantly attenuated respiratory rate during the acclimatization period (novel environment stress). The light stimulus (30-s 2,000 lux) as well as 15-min restraint stress significantly elevated respiratory rate from 95 ± 4.0 to 236 ± 29 cpm and from 117 ± 5.2 to 189 ± 13 cpm, respectively; this response was abolished after the DMH/PeF blockade. We conclude that integrity of the DMH/PeF area is essential for generation of respiratory responses to both stressful and alerting stimuli.

scholarly journals Comparing Benzodiazepines-morphine-induced Respiratory Depression by Analyzing Respiratory Pattern in Rats

2021 ◽  
Vol 23 (6) ◽  
pp. 850-859
Author(s):  
Abbas Alimoradian ◽  
◽  
Saeed Pazhoohan ◽  
Omid Mirzabeygi ◽  
Kiana Naderinia ◽  
...  
Keyword(s):  
Respiratory Depression ◽  
Coefficient Of Variation ◽  
Mean Value ◽  
Respiratory Pattern ◽  
Whole Body ◽  
Medical Sciences ◽  
Ethical Considerations ◽  
Male Wistar Rats ◽  
The Mean ◽  
Whole Body Plethysmography

Background and Aim: Opioid and benzodiazepine family drugs are concurrently used in various patients. Considering the respiratory depressant effects of both classes, in this study, we investigated the effect of coadministration of morphine and several widely used benzodiazepines in the clinic on the rate of respiratory depression in rats. Methods & Materials: Seventy adult male Wistar rats were randomly divided into 10 groups; morphine, midazolam, diazepam, lorazepam, alprazolam, morphine-midazolam, morphine-diazepam, morphine-lorazepam, and morphine-alprazolam. Respiration signal was recorded using whole-body plethysmography 15 minutes after the intraperitoneal injection of the drugs. The respiratory pattern was examined using several parameters; the mean value of inter-breath interval and the respiratory rate, as well as the coefficient of variation and sample entropy analysis of inter-breath interval. Ethical Considerations: This study was approved by the Ethics Committee of Arak University of Medical Sciences (Code: IR.ARAKMU.REC.1397.327). Results: Analyzing respiratory data revealed that injecting the anxiolytic dose of alprazolam, and the combination of morphine-alprazolam and morphine-midazolam, altered the respiratory pattern. Such changes were associated with a decrease in the number of breaths and an increase in the inter-breath interval in the explored test animals, compared with the controls. The obtained data also indicated that morphine-midazolam injection increased the variability of the breathing pattern; such an alternation was associated with increased irregularity and decreased coefficient of variation of the inter-breath interval. Conclusion: The present research results suggested that the short-term injection of morphine-midazolam changes the respiratory pattern more severely than morphine combined with other benzodiazepines.

The respiratory responses of the fowl to hot climates

1982 ◽  
Vol 97 (1) ◽  
pp. 301-309
Author(s):  
H. Kassim ◽  
A. H. Sykes
Keyword(s):  
Heat Stress ◽  
Tidal Volume ◽  
Respiratory Rate ◽  
Linear Relation ◽  
Domestic Fowl ◽  
Whole Body ◽  
Second Phase ◽  
Direct Relation ◽  
Ambient Temperatures ◽  
Respiratory Responses

Respiratory rate (f) and tidal volume (VT) have been measured at normal and at warm ambient temperatures (Ta) in adult domestic fowl by means of a whole body plethysmograph. Resting values of f = 23 +/− 9 min-1 and of VT = 25.6 +/− 0.9 ml min-1 were found. At Ta 30, 35 or 40 degrees C f increased in direct relation to the severity of the heat stress reaching a maximum values of 273 +/− 12 min-1; VT fell uniformly in all three climates to a minimum of 9.0 +/− 0.5 ml. Total ventilation (V) showed a linear relation with f during first-phase panting. Second-phase panting occurred only at Ta 40 degrees C; V increased at first but subsequently fell as the decline in f became more pronounced.

scholarly journals Evaluation of the Antiasthmatic Activity of Methanolic Extract of Trigonella Foenum Graecum on Experimental Models of Bronchial Asthma

2020 ◽  
Vol 10 (1) ◽  
pp. 101-106
Author(s):  
Pankaj G Jain ◽  
Pramod P Patil ◽  
Sushil D Patil ◽  
Savita D Patil ◽  
Sanjay J. Surana
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Guinea Pigs ◽  
Methanolic Extract ◽  
Experimental Models ◽  
Whole Body ◽  
Body Plethysmography ◽  
Trigonella Foenum Graecum ◽  
Respiratory Parameters ◽  
Whole Body Plethysmography

The present study deals with the phytochemical screening and evaluation of antiasthmatic activity of methanolic extract of Trigonella foenumgraecum on experimental models of bronchial asthma and anaphylaxis. The antiasthmatic activity was studied on histamine-induced bronchospasm in guinea pig (Dunkey-Hartley) for respiratory parameters such as maximum airflow, minimum airflow, tidal volume, respiratory rate, minute volume, specific airway resistance determination on double chambered whole body plethysmography on un-anesthetized guinea pigs, for mast cell degranulation by compound 48/80 (in vitro) was done using rat (Albino Wistar) peritoneal fluid. Trigonella foenum graecum treated result indicated significant protection against histamine-induced bronchospasm in guinea pigs at highest dose i.e. 400mg/kg. The bronchodilatory effect of Trigonella foenum graecum was found comparable to the protection offered by the standard drug Salbutamol on respiratory parameters in double chambered whole body plethysmography, Treatment with Trigonella foenum graecum at a dose of 400mg/kg showed a significant decrease in degranulation rate of actively and passively sensitized mast cells of sensitized rats when challenged with antigen. Trigonella foenum graecum. Possess significant anti-asthmatic activity due to its potential anti inflammatory, antioxidant and the antihistaminic activity, which reflects as anti-degranulating effect on mast cells and on respiratory parameters. Keywords: Trigonella foenum graecum; asthma; mast cell; compound 48/80; histamine

Whole-body plethysmography, does it measure tidal volume of small animals?

1998 ◽  
Vol 76 (10-11) ◽  
pp. 945-951 ◽  
Author(s):  
Goran Enhorning ◽  
Sandrijn van Schaik ◽  
Claes Lundgren ◽  
Ida Vargas
Keyword(s):  
Tidal Volume ◽  
Respiratory Rate ◽  
Airway Resistance ◽  
Pressure Oscillation ◽  
Whole Body ◽  
Polyethylene Tube ◽  
Temperature And Humidity ◽  
Metal Bellows ◽  
Pressure Changes ◽  
Whole Body Plethysmography

A whole-body plethysmograph was used for mice. The increase in pressure caused by each inhalation was equivalent to the increase that could be calculated to result from heating and humidification of the inhaled air. However, comprehending that a drop in temperature and humidity would cause an abrupt pressure decline during exhalation was difficult. Pressure changes in the plethysmograph were also studied with an artificial chest, modeling the respiratory mechanics, but without the "inhaled" air being heated or humidified. The "chest" consisted of a metal bellows oscillated by a stepper motor 25 to 175 times per minute. Hereby air (0.05 to 0.20 mL) moved in and out of the bellows. The air passed through a polyethylene tube, the length of which was proportional to "airway resistance" and varied from 5 to 35 cm. It was found that the pressure oscillation was affected not only by "tidal volume" of the mechanical chest but also by "respiratory rate" and by "airway resistance." We concur with previous investigators that the plethysmograph pressure reflects alveolar pressure and that fluctuations cannot be explained by changes in temperature and humidity. Accordingly, tidal volume can only be qualitatively and not quantitatively assessed.Key words: tidal volume, airway resistance, respiratory rate, chest model.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Aktivitätskonzentration der vom Personal einer Radiojodtherapiestation eingeatmeten Luft

1987 ◽  
Vol 26 (03) ◽  
pp. 143-146 ◽  
Author(s):  
H. Fill ◽  
M. Oberladstätter ◽  
J. W. Krzesniak
Keyword(s):  
Nuclear Medicine ◽  
Length Of Stay ◽  
Activity Concentration ◽  
Threshold Value ◽  
Whole Body ◽  
Therapeutic Activity ◽  
External Radiation ◽  
Oral Application ◽  
Exhaled Air ◽  
The Mean

The mean activity concentration of1311 during inhalation by the nuclear medicine personnel was measured at therapeutic activity applications of 22 GBq (600 mCi) per week. The activity concentration reached its maximum in the exhaled air of the patients 2.5 to 4 hours after oral application. The normalized maximum was between 2 • 10−5 and 2 • 10−3 Bq-m−3 per administered Bq. The mean activity concentration of1311 inhaled by the personnel was 28 to 1300 Bq-m−3 (0.8 to 35 nCi-rrf−3). From this the1311 uptake per year was estimated to be 30 to 400 kBq/a (x̄ = 250, SD = 50%). The maximum permitted uptake from air per year is, according to the German and Austrian radiation protection ordinances 22/21 µiCi/a (= 8 • 105 Bq/a). At maximum 50% and, on the average, 30% of this threshold value are reached. The length of stay of the personnel in the patient rooms is already now limited to such an extent that 10% of the maximum permissible whole-body dose for external radiation is not exceeded. Therefore, increased attention should be paid also to radiation exposure by inhalation.

scholarly journals Kinetic analysis and optimisation of 18F-rhPSMA-7.3 PET imaging of prostate cancer

2021 ◽  
Author(s):  
Simona Malaspina ◽  
Vesa Oikonen ◽  
Anna Kuisma ◽  
Otto Ettala ◽  
Kalle Mattila ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Metastatic Disease ◽  
Uptake Kinetics ◽  
Whole Body ◽  
Target Area ◽  
Post Injection ◽  
The Mean ◽  
Pet Radiopharmaceutical ◽  
Time Frames ◽  
Over Time

Abstract Purpose This phase 1 open-label study evaluated the uptake kinetics of a novel theranostic PET radiopharmaceutical, 18F-rhPSMA-7.3, to optimise its use for imaging of prostate cancer. Methods Nine men, three with high-risk localised prostate cancer, three with treatment-naïve hormone-sensitive metastatic disease and three with castration-resistant metastatic disease, underwent dynamic 45-min PET scanning of a target area immediately post-injection of 300 MBq 18F-rhPSMA-7.3, followed by two whole-body PET/CT scans acquired from 60 and 90 min post-injection. Volumes of interest (VoIs) corresponding to prostate cancer lesions and reference tissues were recorded. Standardised uptake values (SUV) and lesion-to-reference ratios were calculated for 3 time frames: 35–45, 60–88 and 90–118 min. Net influx rates (Ki) were calculated using Patlak plots. Results Altogether, 44 lesions from the target area were identified. Optimal visual lesion detection started 60 min post-injection. The 18F-rhPSMA-7.3 signal from prostate cancer lesions increased over time, while reference tissue signals remained stable or decreased. The mean (SD) SUV (g/mL) at the 3 time frames were 8.4 (5.6), 10.1 (7) and 10.6 (7.5), respectively, for prostate lesions, 11.2 (4.3), 13 (4.8) and 14 (5.2) for lymph node metastases, and 4.6 (2.6), 5.7 (3.1) and 6.4 (3.5) for bone metastases. The mean (SD) lesion-to-reference ratio increases from the earliest to the 2 later time frames were 40% (10) and 59% (9), respectively, for the prostate, 65% (27) and 125% (47) for metastatic lymph nodes and 25% (19) and 32% (30) for bone lesions. Patlak plots from lesion VoIs signified almost irreversible uptake kinetics. Ki, SUV and lesion-to-reference ratio estimates showed good agreement. Conclusion 18F-rhPSMA-7.3 uptake in prostate cancer lesions was high. Lesion-to-background ratios increased over time, with optimal visual detection starting from 60 min post-injection. Thus, 18F-rhPSMA-7.3 emerges as a very promising PET radiopharmaceutical for diagnostic imaging of prostate cancer. Trial Registration NCT03995888 (24 June 2019).

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