scholarly journals The role of hydrogen sulphide in the control of breathing in hypoxic zebrafish (Danio rerio)

2014 ◽  
Vol 592 (14) ◽  
pp. 3075-3088 ◽  
Author(s):  
Cosima S. Porteus ◽  
Sara J. Abdallah ◽  
Jacob Pollack ◽  
Yusuke Kumai ◽  
Raymond W. M. Kwong ◽  
...  
Keyword(s):  
Hydrogen Sulphide ◽  
Danio Rerio ◽  
Control Of Breathing

scholarly journals Role of endogenous carbon monoxide in the control of breathing in zebrafish (Danio rerio)

2016 ◽  
Vol 311 (6) ◽  
pp. R1262-R1270 ◽  
Author(s):  
Velislava Tzaneva ◽  
Steve F. Perry
Keyword(s):  
Carbon Monoxide ◽  
Danio Rerio ◽  
Larval Fish ◽  
Protoporphyrin Ix ◽  
Control Of Breathing ◽  
Zinc Protoporphyrin ◽  
Hypoxic Conditions ◽  
First Time

Carbon monoxide (CO) is a gaseous signaling molecule and is produced in vivo from the intracellular breakdown of heme via the heme oxygenase (HO) family of enzymes. In this study we investigated the role of the HO-1/CO system in the control of ventilation in zebrafish, Danio rerio. Immunohistochemistry revealed the presence of HO-1 in the chemoreceptive neuroepithelial cells (NECs) of larvae (4 days postfertilization) and adults, indicating the potential for endogenous CO production in the NECs. Hypoxia (20 min, water Po2 of 30 mmHg) caused a significant increase in HO-1 activity in whole larvae and in the gills of adult fish. Zebrafish with reduced HO-1 activity (via HO-1 knockdown in larvae or zinc protoporphyrin IX treatment in adults) exhibited increased ventilation frequency ( Vf) under normoxic but not hypoxic conditions. The addition of exogenous CO restored resting Vf in fish with diminished CO production, and in some cases (e.g., hypoxic sham larvae) CO modestly reduced Vf below resting levels. Larval fish were treated with phenylhydrazine (PHZ) to eliminate the potential confounding effects of CO-hemoglobin interactions that might influence ventilation. PHZ treatment did not cause changes in Vf of normoxic larvae, and the addition of CO to PHZ-exposed larvae resulted in a significant decrease in sham and HO-1-deficient fish under normoxic conditions. This study demonstrates for the first time that CO plays an inhibitory role in the control of breathing in larval and adult zebrafish.

scholarly journals Learning by Doing: The Use of Distance, Corners and Length in Rewarded Geometric Tasks by Zebrafish (Danio rerio)

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2001
Author(s):  
Greta Baratti ◽  
Angelo Rizzo ◽  
Maria Elena Miletto Petrazzini ◽  
Valeria Anna Sovrano
Keyword(s):  
Danio Rerio ◽  
Three Dimensional ◽  
Reference Memory ◽  
Spatial Abilities ◽  
Learning By Doing ◽  
Surface Distance ◽  
Extended Surfaces ◽  
Unequal Length ◽  
Over Time

Zebrafish spontaneously use distance and directional relationships among three-dimensional extended surfaces to reorient within a rectangular arena. However, they fail to take advantage of either an array of freestanding corners or an array of unequal-length surfaces to search for a no-longer-present goal under a spontaneous cued memory procedure, being unable to use the information supplied by corners and length without some kind of rewarded training. The present study aimed to tease apart the geometric components characterizing a rectangular enclosure under a procedure recruiting the reference memory, thus training zebrafish in fragmented layouts that provided differences in surface distance, corners, and length. Results showed that fish, besides the distance, easily learned to use both corners and length if subjected to a rewarded exit task over time, suggesting that they can represent all the geometrically informative parts of a rectangular arena when consistently exposed to them. Altogether, these findings highlight crucially important issues apropos the employment of different behavioral protocols (spontaneous choice versus training over time) to assess spatial abilities of zebrafish, further paving the way to deepen the role of visual and nonvisual encodings of isolated geometric components in relation to macrostructural boundaries.

Loss of M2 muscarinic receptor function inhibits development of hypoxic bradycardia and alters cardiac β-adrenergic sensitivity in larval zebrafish (Danio rerio)

2009 ◽  
Vol 297 (2) ◽  
pp. R412-R420 ◽  
Author(s):  
Shelby L. Steele ◽  
Kwok Hong Andy Lo ◽  
Vincent Wai Tsun Li ◽  
Shuk Han Cheng ◽  
Marc Ekker ◽  
...  
Keyword(s):  
Heart Rate ◽  
Muscarinic Receptor ◽  
Danio Rerio ◽  
Antisense Oligonucleotides ◽  
Adrenergic Receptor ◽  
Larval Zebrafish ◽  
M2 Muscarinic Receptor ◽  
Β Adrenergic Receptors ◽  
Relative Mrna Expression

Fish exposed to hypoxia develop decreased heart rate, or bradycardia, the physiological significance of which remains unknown. The general muscarinic receptor antagonist atropine abolishes the development of this hypoxic bradycardia, suggesting the involvement of muscarinic receptors. In this study, we tested the hypothesis that the hypoxic bradycardia is mediated specifically by stimulation of the M2 muscarinic receptor, the most abundant subtype in the vertebrate heart. Zebrafish ( Danio rerio) were reared at two levels of hypoxia (30 and 40 Torr Po2) from the point of fertilization. In hypoxic fish, the heart rate was significantly lower than in normoxic controls from 2 to 10 days postfertilization (dpf). At the more severe level of hypoxia (30 Torr Po2), there were significant increases in the relative mRNA expression of M 2 and the cardiac type β-adrenergic receptors ( β1AR, β2aAR, and β2bAR) at 4 dpf. The hypoxic bradycardia was abolished (at 40 Torr Po2) or significantly attenuated (at 30 Torr Po2) in larvae experiencing M2 receptor knockdown (using morpholino antisense oligonucleotides). Sham-injected larvae exhibited typical hypoxic bradycardia in both hypoxic regimens. The expression of β1AR, β2aAR, β2bAR, and M 2 mRNA was altered at various stages between 1 and 4 dpf in larvae experiencing M2 receptor knockdown. Interestingly, M2 receptor knockdown revealed a cardioinhibitory role for the β2-adrenergic receptor. This is the first study to demonstrate a specific role of the M2 muscarinic receptor in the initiation of hypoxic bradycardia in fish.

scholarly journals Morpholino-Mediated Knockdown of ERα, ERβa, and ERβb mRNAs in Zebrafish (Danio rerio) Embryos Reveals Differential Regulation of Estrogen-Inducible Genes

Endocrinology ◽  
2013 ◽  
Vol 154 (11) ◽  
pp. 4158-4169 ◽  
Author(s):  
Lucinda B. Griffin ◽  
Kathleen E. January ◽  
Karen W. Ho ◽  
Kellie A. Cotter ◽  
Gloria V. Callard
Keyword(s):  
Danio Rerio ◽  
Specific Gene ◽  
Estrogen Action ◽  
Cytochrome P450 Aromatase ◽  
Retained Intron ◽  
Inducible Genes ◽  
Hepatic Genes ◽  
Danio Rerio Embryos

Genetically distinct estrogen receptor (ER) subtypes (ERα and ERβ) play a major role in mediating estrogen actions in vertebrates, but their unique and overlapping functions are not entirely clear. Although mammals have 1 gene of each subtype (ESR1 and ESR2), teleost fish have a single esr1 (ERα) and 2 esr2 (ERβa and ERβb) genes. To determine the in vivo role of different ER isoforms in regulating estrogen-inducible transcription targets, zebrafish (Danio rerio) embryos were microinjected with esr-specific morpholino (MO) oligonucleotides to disrupt splicing of the exon III/intron III junction in the DNA-binding domain. Each MO knocked down its respective normal transcript and increased production of variants with a retained intron III (esr1 MO) or a deleted or mis-spliced exon III (esr2a and esr2b MOs). Both esr1 and esr2b MOs blocked estradiol induction of vitellogenin and ERα mRNAs, predominant hepatic genes, but esr2b was the only MO that blocked induction of cytochrome P450 aromatase B mRNA, a predominant brain gene. Knockdown of ERβa with the esr2a MO had no effect on estrogen induction of the 3 mRNAs but, when coinjected with esr1 MO, attenuated the effect of ERα knockdown. Results indicate that ERα and ERβb, acting separately or cooperatively on specific gene targets, are positive transcriptional regulators of estrogen action, but the role of ERβa, if any, is unclear. We conclude that MO technology in zebrafish embryos is an advantageous approach for investigating the interplay of ER subtypes in a true physiological context.

The role of hydrogen sulphide in environmental transport of mercury

Nature ◽  
1978 ◽  
Vol 275 (5681) ◽  
pp. 635-637 ◽  
Author(s):  
P. J. CRAIG ◽  
P. D. BARTLETT
Keyword(s):  
Hydrogen Sulphide ◽  
Environmental Transport

scholarly journals Role of midbrain in the control of breathing in anuran amphibians

2007 ◽  
Vol 293 (1) ◽  
pp. R447-R457 ◽  
Author(s):  
Luciane H. Gargaglioni ◽  
Janice T. Meier ◽  
Luiz G. S. Branco ◽  
William K. Milsom
Keyword(s):  
Lung Ventilation ◽  
Control Of Breathing ◽  
Breathing Frequency ◽  
Attentional State ◽  
Anuran Amphibians ◽  
Auditory Integration ◽  
Stimulation Experiments ◽  
Mandibular Branch ◽  
Central Rhythm Generator

The present study was designed to explore systematically the midbrain of unanesthetized, decerebrate anuran amphibians (bullfrogs), using chemical and electrical stimulation and midbrain transections to identify sites capable of exciting and inhibiting breathing. Ventilation was measured as fictive motor output from the mandibular branch of the trigeminal nerve and the laryngeal branch of the vagus nerve. The results of our transection studies suggest that, under resting conditions, the net effect of inputs from sites within the rostral half of the midbrain is to increase fictive breathing frequency, whereas inputs from sites within the caudal half of the midbrain have no net effect on fictive breathing frequency but appear to act on the medullary central rhythm generator to produce episodic breathing. The results of our stimulation experiments indicate that the principal sites in the midbrain that are capable of exciting or inhibiting the fictive frequency of lung ventilation, and potentially clustering breaths into episodes, appear to be those primarily involved in visual and auditory integration, motor functions, and attentional state.

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