scholarly journals Role of deep breaths in ultrasonic vocal production of Sprague-Dawley rats

2020 ◽  
Vol 123 (3) ◽  
pp. 966-979 ◽  
Author(s):  
Tobias Riede ◽  
Charles Schaefer ◽  
Amy Stein

Deep breaths are one of three breathing patterns in rodents characterized by an increased tidal volume. While humans incorporate deep breaths into vocal behavior, it was unknown whether nonhuman mammals use deep breaths for vocal production. We have utilized subglottal pressure recordings in awake, spontaneously behaving male Sprague-Dawley rats in five contexts: sleep, rest, noxious stimulation, exposure to a female in estrus, and exposure to an unknown male. Deep breaths were produced at rates ranging between 17.5 and 90.3 deep breaths per hour. While overall breathing and vocal rates were higher in social and noxious contexts, the rate of deep breaths was only increased during the male’s interaction with a female. Results also inform our understanding of vocal-respiratory integration in rats. The rate of deep breaths that were associated with a vocalization during the exhalation phase increased with vocal activity. The proportion of deep breaths that were associated with a vocalization (on average 22%) was similar to the proportion of sniffing or eupnea breaths that contain a vocalization. Therefore, vocal motor patterns appear to be entrained to the prevailing breathing rhythm, i.e., vocalization uses the available breathing pattern rather than recruiting a specific breathing pattern. Furthermore, the pattern of a deep breath was different when it was associated with a vocalization, suggesting that motor planning occurs. Finally, deep breaths are a source for acoustic variation; for example, call duration and fundamental frequency modulation were both larger in 22-kHz calls produced following a deep inhalation. NEW & NOTEWORTHY The emission of a long, deep, audible breath can express various emotions. The investigation of deep breaths, also known as sighing, in a nonhuman mammal demonstrated the occasional use of deep breaths for vocal production. Similar to the human equivalent, acoustic features of a deep breath vocalization are characteristic.

1994 ◽  
Vol 76 (6) ◽  
pp. 2333-2341 ◽  
Author(s):  
Y. R. Kou ◽  
C. J. Lai

The acute ventilatory response to inhalation of wood smoke was studied in 58 anesthetized Sprague-Dawley rats. Wood smoke (approximately 6 ml) was inhaled spontaneously via a tracheal cannula. Within the first two breaths of smoke inhalation, either a slowing of respiration (SR) (n = 39) or an augmented inspiration (AI) (n = 19) was elicited consistently in each rat. The SR was primarily due to a prolongation of expiratory duration, whereas the AI was characterized by a two-step inspiratory flow leading to an exceedingly large tidal volume. Both initial responses, usually accompanied by bradycardia and hypotension, were reduced by inhaling smoke at a decreased concentration. After these initial responses, a delayed tachypnea developed and reached its peak 6–10 breaths after inhalation of smoke. Both the SR and AI were completely abolished by bilateral cervical vagotomy. In contrast, the delayed tachypneic response was not prevented by vagotomy but was significantly attenuated by denervation of peripheral chemoreceptors. We conclude that the initial responses to inhalation of several tidal breaths of wood smoke are mediated through vagal bronchopulmonary afferents, whereas the delayed tachypnea may involve nonvagal mechanisms that include a stimulation of peripheral chemoreceptors.


2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Charles Schaefer ◽  
Amy Stein ◽  
Tobias Riede

Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.


Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.


Author(s):  
Russell N. A. Cecil ◽  
H. Clarke Anderson

Unfixed proximal tibial epiphyseal growth plates were studied by freeze-etch to confirm the presence of extracellular calcifying matrix vesicles and to determine the substructure of matrix vesicle membranes as compared to plasma and other membranes of intact chondrocytes. Growth plates from 6-10 week old Sprague-Dawley rats were cut into 1x3 mm blocks whose long dimension was oriented either perpendicular or parallel to the long axis of the tibia. Some blocks were fixed at pH 7. 0 in 0. 2M cacodylate - buffered 2. 5% glutaraldehyde for 1 hour at 4ÅC. The blocks were immersed in 30% glycerol solution at 4ÅC for 1 hour, frozen in liquid nitrogen, and then fractured, etched for 2 minutes, and coated with platinum, carbon and 0. 2% Formvar solution. The replicas were cleaned with chromic acid, floated onto Formvar coated grids, and examined with a Phillips EM 300 electron microscope.Fixed and unfixed specimens appeared similar in ultrastructure. Chondrocytes, matrix, and matrix vesicles were identified. In specimens fractured parallel to the long axis of the tibia, the reserve, proliferative, hypertrophic, and calcifying zones could be discerned as described by light and electron microscopy.


Author(s):  
M. Ashraf ◽  
L. Landa ◽  
L. Nimmo ◽  
C. M. Bloor

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.


Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.


Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.


Author(s):  
A.R. Beaudoin ◽  
G. Grondin ◽  
A. Lord ◽  
M. Pelletier

We have recently described the ultrastructural localization of NADPase activity in the exocrine pancreas of rat. The enzyme was found in the intermediate saccules of the Golgi apparatus, in dense bodies and lysosomes but was absent from zymogen granules. A very intense reaction was noticed in a peculiar structure which was termed “Snake-Like Tubule” (SLT). The purposes of the present study were firstly to delineate SLT distribution in the acinar cell and secondly to define any possible relationship or association with other cellular organelles.NADPase cytochemical reaction was performed on the pancreas of adult Sprague Dawley rats. Small lobules were excised and fixed for 50 min, at 4°C, in 2% glutaraldehyde buffered with 0.1M cacodylate at pH 7.2. Lobules were rinsed several times with the same buffer containing 570 sucrose and cut with a Mcllwayn tissue chopper. Sections were washed several times with buffer and incubated for 2 hr at 37°C in the following medium: 4mM NADPH; 40mM sodium acetate buffer, pH 5.0; 4mM lead acetate and 5% sucrose.


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