A difference in optomotor behaviour of two Antarctic nototheniid fishes is correlated with the presence of a choroid rete mirabile and Root effect

Polar Biology ◽  
2003 ◽  
Vol 26 (6) ◽  
pp. 411-415 ◽  
Author(s):  
Neill A. Herbert ◽  
John A. Macdonald ◽  
Rufus M. G. Wells ◽  
William Davison
Keyword(s):  
Root Effect ◽  
Rete Mirabile ◽  
Optomotor Behaviour

scholarly journals Expression of transport proteins in the rete mirabile of european silver and yellow eel

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gabriel Schneebauer ◽  
Victoria Drechsel ◽  
Ron Dirks ◽  
Klaus Faserl ◽  
Bettina Sarg ◽  
...  
Keyword(s):  
Transport Proteins ◽  
European Eel ◽  
Back Diffusion ◽  
Root Effect ◽  
Rete Mirabile ◽  
Partial Pressures ◽  
Silver Eels ◽  
Ion Channel Proteins ◽  
Gas Molecules ◽  
Gas Gland

Abstract Background In physoclist fishes filling of the swimbladder requires acid secretion of gas gland cells to switch on the Root effect and subsequent countercurrent concentration of the initial gas partial pressure increase by back-diffusion of gas molecules in the rete mirabile. It is generally assumed that the rete mirabile functions as a passive exchanger, but a detailed analysis of lactate and water movements in the rete mirabile of the eel revealed that lactate is diffusing back in the rete. In the present study we therefore test the hypothesis that expression of transport proteins in rete capillaries allows for back-diffusion of ions and metabolites, which would support the countercurrent concentrating capacity of the rete mirabile. It is also assumed that in silver eels, the migratory stage of the eel, the expression of transport proteins would be enhanced. Results Analysis of the transcriptome and of the proteome of rete mirabile tissue of the European eel revealed the expression of a large number of membrane ion and metabolite transport proteins, including monocarboxylate and glucose transport proteins. In addition, ion channel proteins, Ca2+-ATPase, Na+/K+-ATPase and also F1F0-ATP synthase were detected. In contrast to our expectation in silver eels the expression of these transport proteins was not elevated as compared to yellow eels. A remarkable number of enzymes degrading reactive oxygen species (ROS) was detected in rete capillaries. Conclusions Our results reveal the expression of a large number of transport proteins in rete capillaries, so that the back diffusion of ions and metabolites, in particular lactate, may significantly enhance the countercurrent concentrating ability of the rete. Metabolic pathways allowing for aerobic generation of ATP supporting secondary active transport mechanisms are established. Rete tissue appears to be equipped with a high ROS defense capacity, preventing damage of the tissue due to the high oxygen partial pressures generated in the countercurrent system.

Kasuistik – Patientin mit idiopathischer thrombozytopenischer Purpura (ITP) und Moya-Moya-artigem Rete mirabile

2013 ◽  
Vol 44 (01) ◽  
Author(s):  
F Knies ◽  
J Bielig ◽  
T Stift ◽  
S Matutat ◽  
K Mückner ◽  
...  
Keyword(s):  
Rete Mirabile

scholarly journals Histologic Examination of a Sea Pig (Scotoplanes sp.) Using Bright Field Light Microscopy

2021 ◽  
Vol 9 (8) ◽  
pp. 848
Author(s):  
Elise E. B. LaDouceur ◽  
Linda A. Kuhnz ◽  
Christina Biggs ◽  
Alicia Bitondo ◽  
Megan Olhasso ◽  
...  
Keyword(s):  
Deep Sea ◽  
Body Wall ◽  
Monterey Bay ◽  
Bright Field ◽  
Male And Female ◽  
Rete Mirabile ◽  
Lateral Body ◽  
Bright Field Microscopy ◽  
Microscopic Findings ◽  
Tube Feet

Sea pigs (Scotoplanes spp.) are deep-sea dwelling sea cucumbers of the phylum Echinodermata, class Holothuroidea, and order Elasipodida. Few reports are available on the microscopic anatomy of these deep-sea animals. This study describes the histologic findings of two, wild, male and female Scotoplanes sp. collected from Monterey Bay, California. Microscopic findings were similar to other holothuroids, with a few notable exceptions. Sea pigs were bilaterally symmetrical with six pairs of greatly enlarged tube feet arising from the lateral body wall and oriented ventrally for walking. Neither a rete mirabile nor respiratory tree was identified, and the large tube feet may function in respiration. Dorsal papillae protrude from the bivium and are histologically similar to tube feet with a large, muscular water vascular canal in the center. There were 10 buccal tentacles, the epidermis of which was highly folded. Only a single gonad was present in each animal; both male and female had histologic evidence of active gametogenesis. In the male, a presumed protozoal cyst was identified in the aboral intestinal mucosa, and was histologically similar to previous reports of coccidians. This work provides control histology for future investigations of sea pigs and related animals using bright field microscopy.

scholarly journals The Dependence of the Oxygen-Concentrating Mechanism of the Teleost Eye (Salmo gairdneri) on the Enzyme Carbonic Anhydrase

1969 ◽  
Vol 54 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Michael B. Fairbanks ◽  
J. Russell Hoffert ◽  
Paul O. Fromm
Keyword(s):  
Carbonic Anhydrase ◽  
Environmental Water ◽  
Salmo Gairdneri ◽  
Complete Suppression ◽  
Oxygen Inhibition ◽  
Rete Mirabile ◽  
Arterial Blood ◽  
Concentrating Mechanism ◽  
The One ◽  
Erythrocyte Carbonic Anhydrase

Microoxygen polarographic electrodes were constructed and used to measure oxygen tension (POO2) in the eyes of rainbow trout (Salmo gairdneri). The values obtained are compared with arterial blood and environmental water POO2 and indicate that there is an oxygen-concentrating mechanism in the eye supplying oxygen to the avascular retina. Anatomically similar retes suggest that the mechanism is similar to the one which exists in the swim bladder. Elimination of the arterial blood supply to the choroidal gland rete mirabile of the eye (through pseudobranchectomy) and the consequent lowering of ocular oxygen tensions implicate the choroidal gland as one of the major components of the oxygen-concentrating mechanism. After pseudobranchectomy the presence of ocular POO2 above that of arterial blood is indicative of a secondary structure in the eye capable of concentrating oxygen. Inhibition of carbonic anhydrase, using acetazolamide, is shown to result in complete suppression of the oxygen-concentrating mechanism. A hypothesis is advanced for the participation of retinal-choroidal and erythrocyte carbonic anhydrase in the oxygen-concentrating mechanism.

Abstract 3482: Increased Matrix Metalloproteinase-9 Expression is Correlated with Carotid Intraplaque hemorrhage in a Swine Model

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Zhong-Song Shi ◽  
Xiao-Bing Jiang ◽  
Jin-Shan Wang ◽  
Wei-Si Yuan ◽  
Dong-Hong Liu
Keyword(s):  
Carotid Artery ◽  
Matrix Metalloproteinase ◽  
Vulnerable Plaque ◽  
Carotid Plaque ◽  
Carotid Atherosclerosis ◽  
Intraplaque Hemorrhage ◽  
Swine Model ◽  
Carotid Plaques ◽  
Rete Mirabile ◽  
Atherosclerotic Changes

Purpose: The limited number of large animal carotid atherosclerotic models restricts the preclinical evaluation of endovascular therapies. Carotid intraplaque hemorrhage may be associated with a higher risk of ischemic stroke in patients with carotid disease. In this study, we assess the association of the lesional expression of matrix metalloproteinase (MMP)-9 with vulnerable atherosclerotic carotid plaque and intraplaque hemorrhage in a Swine model. Materials and Methods: Carotid atherosclerosis was induced in miniswines using the combination of partial ligation and high cholesterol diet, and a minimum 70% stenosis was confirmed by Doppler ultrasonography immediately post-ligation. Carotid artery sections were obtained for histopathological examination and immunohistochemical study for MMP-9 at three months. Distal embolism was determined by the presence of atheroemboli in the ipsilateral rete mirabile. Atherosclerotic changes were classified by AHA/Stary stage (type I to VI). The association of distal embolism in the rete mirabile with vulnerable carotid plaque was analyzed. The association of MMP-9 expression in the plaque with the vulnerable plaque and intraplaque hemorrhage was further analyzed. Results: One hundred ninety-one carotid segments from ten carotid artery models were assessed. Among 139 segments with atherosclerotic changes, 102 segments had vulnerable plaque (Stary IV to VI). Vulnerable atherosclerotic plaques were found more frequently in the vessel wall proximal to the partial ligation than distal ( P <0.0001). Distal embolism was found in all 10 rete mirabilis, and deemed to be from the ipsilateral vulnerable carotid plaques. Areas positive for MMP-9 tended to be greater in the vulnerable plaque than in the stable plaque (8.69 ± 0.73% vs. 7.04 ± 0.94%, p=0.35). Areas positive for MMP-9 were significantly greater in the plaque with intraplaque hemorrhage than in the plaque without intraplaque hemorrhage (11.84 ± 1.22% vs. 6.63 ± 0.59%, p<0.001). On multivariate analysis, positive expression of MMP-9 was an independent predictor of intraplaque hemorrhage (p=0.007). Conclusion: Vulnerable carotid plaques with distal embolism were created in a Swine model of carotid atherosclerosis. Increased expression of MMP-9 may be associated with vulnerable carotid plaques, especially having the feature of intraplaque hemorrhage.

BLIND MEXICAN CAVE FISH (ASTYANAX HUBBSI) RESPOND TO MOVING VISUAL STIMULI

1994 ◽  
Vol 188 (1) ◽  
pp. 89-101 ◽  
Author(s):  
T Teyke ◽  
S Schaerer
Keyword(s):  
Visual Stimulus ◽  
Swimming Velocity ◽  
Environmental Cues ◽  
Cave Fish ◽  
Optomotor Response ◽  
Aquarium Fish ◽  
Modified Theory ◽  
Test Aquarium ◽  
Optomotor Behaviour

In apparatus for measuring optomotor behaviour, blind Mexican cave fish, Astyanax hubbsi, increase their swimming velocity upon rotation of a striped cylinder, i.e. in response to a solely visual stimulus. The fish follow the movements of the stripes at (i) rotation velocities between 60 degrees s-1 and 80 degrees s-1, (ii) light intensities of less than 20 lx and, (iii) stimulus widths subtending an angle of less than 1 &deg;. Extirpation of the vestigial eye structures does not affect the response to the moving visual stimulus, which indicates that the response is mediated by extra-ocular photoreceptors. An optomotor response can be reliably evoked in a round test aquarium. Fish do not respond when the test aquarium contains environmental cues, such as bars on the wall or when a section of the round aquarium is divided off. This indicates that the fish obtain information about their environment from different sensory sources and that the visual stimulus is effective only when no other means of orientation are available. We suggest a modified theory of the optomotor response, which emphasizes the crucial role of the environment in eliciting the response and which permits behaviours more complex than just following the stimulus.

scholarly journals Predominance of soil vs root effect in rhizosphere microbiota reassembly

2019 ◽  
Vol 95 (10) ◽  
Author(s):  
Mengli Zhao ◽  
Jun Yuan ◽  
Zongzhuan Shen ◽  
Menghui Dong ◽  
Hongjun Liu ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Disease Incidence ◽  
Bulk Soil ◽  
Pathogen Population ◽  
Root Effect ◽  
Rhizosphere Microbiome ◽  
Distinct Disease ◽  
Pathogenic Microbes ◽  
Disease Suppressive Soil ◽  
Rhizosphere Community

ABSTRACT Rhizosphere community assembly is simultaneously affected by both plants and bulk soils and is vital for plant health. However, it is still unclear how and to what extent disease-suppressive rhizosphere microbiota can be constructed from bulk soil, and the underlying agents involved in the process that render the rhizosphere suppressive against pathogenic microbes remain elusive. In this study, the evolutionary processes of the rhizosphere microbiome were explored based on transplanting plants previously growing in distinct disease-incidence soils to one disease-suppressive soil. Our results showed that distinct rhizoplane bacterial communities were assembled on account of the original bulk soil communities with different disease incidences. Furthermore, the bacterial communities in the transplanted rhizosphere were noticeably influenced by the second disease-suppressive microbial pool, rather than that of original formed rhizoplane microbiota and homogenous nontransplanted rhizosphere microbiome, contributing to a significant decrease in the pathogen population. In addition, Spearman's correlations between relative abundances of bacterial taxa and the abundance of Ralstonia solanacearum indicated Anoxybacillus, Flavobacterium, Permianibacter and Pseudomonas were predicted to be associated with disease-suppressive function formation. Altogether, our results showed that bulk soil played an important role in the process of assembling and reassembling the rhizosphere microbiome of plants.

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