GABA Receptor Inhibition and Severe Hypoxia Induce a Paroxysmal Depolarization Shift in Goldfish Neurons

Journal of Neurophysiology ◽

10.1152/jn.00149.2020 ◽

2020 ◽

Author(s):

Leslie Thomas Buck ◽

Nariman Hossein-Javaheri

Keyword(s):

Gaba Receptor ◽

Carassius Auratus ◽

Threshold Current ◽

Protective Mechanisms ◽

Gabaergic Neurotransmission ◽

Goldfish Carassius Auratus ◽

Receptor Inhibition ◽

Paroxysmal Depolarization Shift ◽

Excitotoxic Cell Death ◽

First Time

Mammalian neurons undergo rapid excitotoxic cell death when deprived of oxygen; however, the common goldfish (Carassius auratus) has the unique ability of surviving in oxygen-free waters. This organism utilizes γ-amino butyric acid (GABA) signaling to suppress excitatory glutamatergic activity during anoxic periods. Although GABAA receptor antagonists are not detrimental to the cell, co-inhibition of GABAA and GABAB receptors is detrimental by abolishing anoxia-induced neuro-protective mechanisms. In this article we show that blocking anoxic GABAergic neurotransmission induces seizure-like activity (SLA) analogous to a paroxysmal depolarization shift (PDS), with an elevation in action potential (AP) threshold and threshold current. The observed PDS was attributed to an increase in excitatory post-synaptic potential (EPSP) currents that are normally attenuated with decreasing oxygen levels. Furthermore, for the first time, we show that in addition to PDS, some neurons undergo depolarization block and do not generate AP despite a supra threshold membrane potential. In conclusion, our results indicate that with anoxia and absence of GABA receptor activity, telencephalic neurons of Carassius auratus manifest a paroxysmal depolarization shift, a key feature of epileptic discharge.

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The Nacteous (Mottled) Group of the Goldfish (Carassius auratus L.), with an Analysis of the Colours Seen in these Fish

Marine and Freshwater Research ◽

10.1071/mf9520126 ◽

1952 ◽

Vol 3 (2) ◽

pp. 126 ◽

Cited By ~ 1

Author(s):

RJ Affleck

Keyword(s):

Carassius Auratus ◽

Yellow Pigment ◽

The Body ◽

Red Pigment ◽

Orange Pigment ◽

Black Smoke ◽

Goldfish Carassius Auratus ◽

Orange Yellow ◽

Yellow Pigments ◽

First Time

The colours of nacreous (mottled) fish are usually mottled but specimens do occur in which only one kind of the black, orange, or yellow chromatophores is present, while some lack pigments over most of the body. The colours appear metallic, pearl, or matt depending on the presence or absence of reflecting tissue in two definite layers. The hues seen in these fish are black, smoke, blue, orange, yellow, blood-red, and silver, which occur singly or in combinations. These hues are produced by black, orange, and yellow pigments in chromatophores, silver reflectillg tissue, and haemoglobin in the blood. The presence of a yellow pigment — a carotenoid — is reported for the first time. Although the colour red has been reported no red pigment has ever been described. An intense orange pigment will produce a red effect on a pale blood-red background. The nacreous (mottled) group of the goldfish is intermediate between the metallic (scaled) and matt (transparent) groups with regard to the amount of reflecting tissue. The colours of these fish may not be used as criteria of the groups.

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Light and scanning electron microscopic studies of Myxobolus indica n. sp. and a report of three Myxozoan (Myxosporea: Bivalvulida) parasites of cultured ornamental goldfish, Carassius auratus L. for the first time in India

Aquaculture Reports ◽

10.1016/j.aqrep.2017.05.006 ◽

2017 ◽

Vol 7 ◽

pp. 66-76 ◽

Cited By ~ 4

Author(s):

Mandira Saha ◽

P.K. Bandyopadhyay

Keyword(s):

Carassius Auratus ◽

Electron Microscopic ◽

Goldfish Carassius Auratus ◽

Scanning Electron Microscopic ◽

Microscopic Studies ◽

First Time ◽

Scanning Electron

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SEM of Hepatocytes and Biliary Passages in Goldfish Liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080213 ◽

1977 ◽

Vol 35 ◽

pp. 556-557

Author(s):

Waykin Nopanitaya ◽

Joe W. Grisham ◽

Johnny L. Carson

Keyword(s):

Carassius Auratus ◽

Cell Layer ◽

Three Dimensional ◽

Cell Types ◽

Biliary System ◽

Fish Food ◽

Commercial Fish ◽

Goldfish Carassius Auratus ◽

Commercial Fish Food

An interesting feature of the goldfish liver is the morphology of the hepatic plate, which is always formed by a two-cell layer of hepatocytes. Hepatic plates of the goldfish liver contain an infrequently seen second type of cell, in the centers of plates between two hepatocytes. A TEH study by Yamamoto (1) demonstrated ultrastructural differences between hepatocytes and centrally located cells in hepatic plates; the latter were classified as ductule cells of the biliary system. None of the previous studies clearly showed a three-dimensional organization of the two cell types described. In the present investigation we utilize SEM to elucidate the arrangement of hepatocytes and bile ductular cells in intralobular plates of goldfish liver.Livers from young goldfish (Carassius auratus), about 6-10 cm, fed commercial fish food were used for this study. Hepatic samples were fixed in 4% buffered paraformaldehyde, cut into pieces, fractured, osmicated, CPD, mounted Au-Pd coated, and viewed by SEM at 17-20 kV. Our observations were confined to the ultrastructure of biliary passages within intralobular plates, ductule cells, and hepatocytes.

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