Ribbon synapses of the vertebrate retina are specialized synapses that release neurotransmitter by synaptic vesicle exocytosis in a manner that is proportional to the level of depolarization of the cell. This release property is different from conventional neurons, in which the release of neurotransmitter occurs as a short-lived burst triggered by an action potential. Synaptic vesicle exocytosi...

Unlike mammals, bony fish have two type II interferons, IFNgamma and IFNgammarel, whose pro-inflammatory functions have not been fully characterized. To elucidate the distinct roles of these type II interferons of bony fish, we examined the effects of recombinant goldfish (rg) IFNgamma and IFNgammarel on the macrophage antimicrobial responses, immune gene expression, and their signaling pathway...

PURPOSE Insulin is a peptide growth factor that is active in most tissues, both during development and in adulthood. The action of insulin is through its specific membrane receptor. Previously retinal progenitors in the adult goldfish were shown to proliferate vigorously when exposed to insulin in vitro.(1) The present study was undertaken to clone and characterize partial cDNAs that encode the...

In goldfish, growth hormone (GH) transiently rises 30 min after meals, returning to baseline at 1 h postmeal. Somatostatin (SRIF) is the major inhibitor of GH release. Three cDNAs encoding pre-pro-SRIF (PSS) have been previously cloned from goldfish brain: PSS-I, which encodes SRIF-14; PSS-II, which is potentially processed into gSRIF-28 that has [Glu(1),Tyr(7)(,)Gly(10)]SRIF-14 at the COOH ter...

Encounters of regenerating goldfish retinal axons with oligodendrocytes and CNS myelin of mammals and fish were monitored in in vitro assays. Upon contact with highly branched rat oligodendrocytes, goldfish axons collapsed or grew around but never crossed these cells. However, in the presence of the antibody IN-1 against the oligodendrocyte-associated growth-inhibitory proteins, axons did grow ...

Encounters of regenerating goldfish retinal axons with oligodendrocytes and CNS myelin of mammals and fish were monitored in in vitro assays. Upon contact with highly branched rat oligodendrocytes, goldfish axons collapsed or grew around but never crossed these cells. However, in the presence of the antibody IN-1 against the oligodendrocyteassociated growth-inhibitory proteins, axons did grow o...

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...