Morphological differences in adipose tissue and changes in BDNF/Trkb expression in brain and gut of a diet induced obese zebrafish model.

Obesity is a multifactorial disease generated by an alteration in balance between energy intake and expenditure, also dependent on genetic and non-genetic factors. Moreover, various nuclei of the hypothalamus receive and process peripheral stimuli from the gastrointestinal tract, controlling food intake and therefore energy balance. Among anorexigenic molecules, brain-derived neurotrophic factor (BDNF) acts through the tyrosine-kinase receptor TrkB.

Topographical and drug specific sensitivity of hair cells of the zebrafish larvae to aminoglycoside-induced toxicity.

The hair cells of the lateral line system of fishes are morphologically and physiologically similar to the hair cells of the mammalian inner ear, also sharing its molecular characteristics. For this reason, it has been used as a powerful animal model to analyze in vivo ototoxicity. In this work, we examined the dose-dependent effects of two potent ototoxic aminoglycosides, neomycin and gentamicin, on the hair cells of two selected neuromasts (L1 and T1, the first of the trunk and the terminal located in the fin, respectively) of the lateral line in the ET4 transgenic zebrafish line.

Rodlet cells development in the intestine of sea bass (Dicentrarchus labrax).

The enigmatic rodlet cells (RCs) are characterized by conspicuous inclusions named "rodlets". They were discovered over 100 years ago and were considered as parasites but shortly afterward interpreted as endogenous cells. The RCs have been described in different tissues of marine and freshwater teleosts, but their origin and function remain unknown.

Morphology of the European sea bass (Dicentrarchus labrax) tongue.

The European sea bass, a member of the Moronidae family, is a food fish, considered one of the first models for the intensive breeding in salt water. It has nowadays an important and increasing presence in the international fishing markets. Sea basses are carnivorous, feeding on little fishes and invertebrates.

Rhodopsin expression in the zebrafish pineal gland from larval to adult stage.

The zebrafish pineal gland plays an important role in different physiological functions including the regulation of the circadian clock. In the fish pineal gland the pinealocytes are made up of different segments: outer segment, inner segment and basal pole. Particularly, in the outer segment the rhodopsin participates in the external environment light reception that represents the first biochemical step in the melatonin production.

The photoreceptive cells of the pineal gland in adult zebrafish (Danio rerio).

The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail.

Aquaporin 4 in the sensory organs of adult zebrafish (Danio rerio).

The aquaporins (AQPs) are a family (AQP-AQP10) of transmembrane channel proteins that mediate the transport of water, ions, gases, and small molecules across the cell membrane, thus regulating cell homeostasis. AQP4 has the highest water permeability and it is involved in hearing and vision in mammals. Here, we used immunohistochemistry to map the presence of AQP4 in the sensory organs of adult zebrafish.

Developmental changes in the expression of Sox2 in the zebrafish brain.

The family of B1 Sox transcription factors plays critical roles in the early stages of development, including the central nervous system. It was demonstrated that Sox2 is expressed in repressed neural stem cells. Therefore, we decided to investigate the expression of Sox2 in the brain of zebrafish at different ages to identify potential neurogenic areas, and to establish the developmental changes they undergo.

Age-dependent changes in the pigeon bursa of Fabricius vasculature: a comparative study using light microscopy and scanning electron microscopy of vessel casts.

The present study was carried out to analyse the vascularization of the pigeon bursa cloacalis of Fabricius and to determine whether it undergoes age-dependent changes during its functionally most important growth period after hatching of the pigeon. Morphological assessment of vascular corrosion casts, studied qualitatively and quantitatively, was applied for the first time to investigate the vascularization of the pigeon pigeon bursa of Fabricius. This also allowed us to analyse the microvasculature and morphological aspects of the vessel interrelationships as occurring in the natural state.

Age-related changes in the avian primary lymphoid organs (thymus and bursa of Fabricius).

The avian primary lymphoid organs, the thymus and the bursa of Fabricius, undergo age-dependent changes leading in some cases to the complete atrophy of the organ. Nevertheless, the timetable of the involutive process as well as the consequences in the structure and functionality of the organs vary largely in the time frame and structural changes among species. On the other hand, and in contrast with the large body of literature reporting the structural and functional changes in mammalian primary lymphoid organs, the age-dependent changes in avian thymus and bursa of Fabricius are scarce, fragmentary, and heterogeneous.