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The purpose of the present study was to elucidate the possible role of neuropeptide Y (NPY) in the feeding regulation in fish. We examined the effects of intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) neuropeptide Y administration on food intake in satiated goldfish, at different time intervals postinjection (0-2, 2-8 and 0-8 h). Food intake was(More)
It has been suggested that melatonin is synthesized in nonphotosensitive organs of vertebrates in addition to the well-known sites of the pineal gland and retina. However, very few studies have demonstrated the gene expression of melatonin-synthesizing enzymes in extrapineal and extraretinal locations. This study focuses on the circadian expression of the(More)
Little is known about the feeding time dependence of clock gene expression in fish. The aim of the present study was to investigate whether a scheduled feeding time can entrain the rhythmic expression of several clock genes (period and cryptocrome) in the brain and liver of a teleost, the goldfish. Fish maintained under continuous light (LL) conditions were(More)
This work investigated the ability of melatonin to prevent cell damage in the cerebellar cortex of chick embryo caused by glutamate administration. Cell injury was evaluated estimating, at ultrastructural level, the phenomenon of cell death and the synaptogenesis of the Purkinje cells and the cerebellar glomerular synaptic complex. Administration of(More)
The aim of this study was to characterize 2-[125I]iodomelatonin binding sites in the neural retina and central nervous system (telencephalon, diencephalon, and optic tectum) of the anuran amphibian Rana perezi. Saturation and kinetic studies and pharmacological characterization revealed the existence of a unique melatonin-binding site that belongs to the(More)
Leptin is a hormone involved in feeding and body weight regulation in vertebrates, but the relationship between energy status and leptin has not been clearly established in fish. The aim of this study was to investigate in a teleost, the goldfish (Carassius auratus), the tissue expression pattern of two leptins (gLep-aI and gLep-aII) and leptin receptor(More)
The arylalkylamine N-acetyltransferase (AANAT) is a key enzyme in the rhythmic production of melatonin. Two Aanats are expressed in teleost fish, one retinal specific, Aanat1, and the other one pineal specific, Aanat2, being the latter the main enzyme responsible of the plasma nocturnal melatonin increase in fish. In anurans melatonin has been involved in(More)
The present study focused on the effects of a subchronic melatonin treatment on locomotor activity and cortisol plasma levels in goldfish. We compared two different administration routes: peripheral (10 microg/g body weight) versus central (1 microg/microl) injections of melatonin for 7 or 4 days, respectively. Daily locomotor activity, including both(More)
The present study investigates the possible circadian dependence of leptin effects on food intake, locomotor activity, glycemia and plasma cortisol levels in goldfish (Carassius auratus). Fish were maintained under 12L:12D photoperiod and subjected to two different feeding schedules, one group fed during photophase (10:00) and the other one during(More)
The aim of the present study was to investigate how photocycle and feeding-time cues regulate the daily expression of Per1a, Per2a, Per3, and Cry3 in the goldfish hindgut. For this purpose, we studied the daily rhythmicity of these genes in fish maintained under different lighting conditions and under different feeding regimes (scheduled or not). We also(More)