The fish reproductive axis is regulated by many neuroendocrine factors. However, factors involved in the suppression of this axis are largely uncharacterized. In this study, we describe a novel neuropeptide derived from the spexin precursor acting as a negative factor to suppress the reproductive axis in teleost. The cDNA sequences of the spexin precursors have been cloned from both zebrafish a...

Otophysine fishes are characterized by Weberian ossicles connecting the swimbladder to the ear acoustically. In order to determine the degree to which these ossicles contribute to auditory sensitivity, the tripus was unilaterally or bilaterally extirpated in goldfish and hearing thresholds determined. The auditory evoked potential (AEP) recording technique was used to measure auditory sensitivi...

Potassium channel activity is important for modulating mammalian macrophage antimicrobial functions. The involvement of potassium channels in mediation of immune cell function in lower vertebrates, such as teleost, has not been explored. Since relatively little is known about the types of potassium channels present in fish macrophages, pharmacological blockers with broad ranges of activity were...

We examined the expression of metabotropic glutamate (mGlu) receptors in species of fish that differ for their vulnerability to anoxic brain damage. Although expression of mGlu1a and mGlu5 receptors was similar in the brain of all species examined, expression of mGlu2/3 receptors was substantially higher in the brain of anoxia-tolerant species (i.e., the carp Carassius carassius and the goldfis...

Goldfish and rat optic nerves were cut and crushed, respectively, and the expression of the transcription factor proteins c-JUN, JUN B, JUN D, c-FOS, FOS B, KROX-24, and CREB was investigated in retinal ganglion cells (RGCs) by immunocytochemistry. Immunoreactivities (IRs) were followed up to 350 days in the goldfish and up to 22 days in the rat. In RGCs of untreated goldfish and rats, all JUN,...

MAX 350 WORDS) Melatonin is currently proposed to be synthesized in non-photosensitive organs of vertebrates, besides its well-known sites of synthesis, the pineal gland and the retina. However, very few studies have demonstrated gene expression of MEL synthesizing enzymes in extrapineal and extraretinal locations. In the present study, present study focuses on the circadian expression of the t...

In nature, the caudal fins of fish species are frequently lost to some extent by aggressive behaviour, predation and diseases. To test whether the swimming performance of fish with different swimming capacities would be differentially affected due to caudal fin loss and regeneration, we investigated the critical swimming speed (Ucrit), swimming metabolic rate (M(O2)), tail beat frequency (f(TB)...

The present study was conducted to investigate the effect of the diet containing Laurencia caspica (red algae) on blood parameters and digestive enzymes activity of goldfish after 90-day period. Goldfish (weight 6.10±0.1 gr) were divided to four experimental groups (30 individuals in each replication) including experimental treatment of the control group (without using red algae) and three trea...

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