Identification of neural progenitor cells and their progeny reveals long distance migration in the developing octopus brain.

Cephalopods have evolved nervous systems that parallel the complexity of mammalian brains in terms of neuronal numbers and richness in behavioral output. How the cephalopod brain develops has only been described at the morphological level, and it remains unclear where the progenitor cells are located and what molecular factors drive neurogenesis. Using histological techniques, we located dividing cells, neural progenitors and postmitotic neurons in Octopus vulgaris embryos. Our results indicate that an important pool of progenitors, expressing the conserved bHLH transcription factors achaete-scute or neurogenin, is located outside the central brain cords in the lateral lips adjacent to the eyes, suggesting that newly formed neurons migrate into the cords. Lineage-tracing experiments then showed that progenitors, depending on their location in the lateral lips, generate neurons for the different lobes, similar to the squid Doryteuthis pealeii. The finding that octopus newborn neurons migrate over long distances is reminiscent of vertebrate neurogenesis and suggests it might be a fundamental strategy for large brain development.

Octopuses have evolved incredibly large and complex nervous systems that allow them to perform impressive behaviors, like plan ahead, navigate and solve puzzles. The nervous system of the common octopus (also known as Octopus vulgaris) contains over half a billion nerves cells called neurons, similar to the number found in small primates. Two thirds of these cells reside in the octopuses' arms, while the rest make-up a central brain that sits between their eyes. Very little is known about how this central brain forms in the embryo, including where the cells originate and which molecular factors drive their maturation in to adult cells. To help answer these questions, Deryckere et al. studied the brain of Octopus vulgaris at different stages of early development using various cell staining and imaging techniques. The experiments identified an important pool of dividing cells which sit in an area outside the central brain called the 'lateral lips'. In these cells, genes known to play a role in neural development in other animals are active, indicating that the cells had not reached their final, mature state. In contrast, the central brain did not seem to contain any of these immature cells at the point when it was growing the most. To investigate this further, Deryckere et al. used fluorescent markers to track the progeny of the dividing cells during development. This revealed that cells in the lateral lips take on a specific neuronal fate before migrating to their target region in the central brain. Newly matured neurons have also been shown to travel large distances in the embryos of vertebrates, suggesting that this mechanism may be a common strategy for building large, complex brains. Although the nervous system of the common octopus is comparable to mammals, they evolved from a very distant branch of the tree of life; indeed, their last common ancestor was a worm-like animal that lived about 600 million years ago. Studying the brain of the common octopus, as done here, could therefore provide new insights into how complex nervous systems, including our own, evolved over time.

Effects of a Red Orange and Lemon Extract in Obese Diabetic Zucker Rats: Role of Nicotinamide Adenine Dinucleotide Phosphate Oxidase.

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease, worldwide, and oxidative stress has been recognized as a key factor in the pathogenesis and progression of DN. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase has the most important contribution to reactive oxygen species generation during the development of DN. Bioactive compound use has emerged as a potential approach to reduce chronic renal failure. Therefore, a red orange and lemon extract (RLE) rich in anthocyanins was chosen in our study, to reduce the toxic renal effects during the development of DN in Zucker diabetic fatty rat (ZDF). RLE effects were examined daily for 24 weeks, through gavage, in ZDF rats treated with RLE (90 mg/kg). At the end of the experiment, ZDF rats treated with RLE showed a reduction of the diabetes-associated up-regulation of both NOX4 and the p47-phox and p22-phox subunits, and restored the BAX/BCL-2 ratio respect to ZDF rats. Furthermore, RLE was able to reduce the oxidative DNA damage measured in urine samples in ZDF rats. This study showed that RLE could prevent the renal damage induced by DN through its capacity to inhibit NOX4 and apoptosis mechanisms.

Determination of tetrodotoxin (TTX) levels in various tissues of the silver cheeked puffer fish (Lagocephalus sceleratus (Gmelin, 1789)) in Northern Cyprus Sea (Eastern Mediterranean).

Lagocephalus sceleratus from the family Tetraodontidae, which is originated from the Red Sea, started to migrate to Mediterranean waters after the opening of the Suez Channel in 1869. Since they do not have any predators in the Mediterranean Sea, their population increased in number very fast. Different tissues of L. sceleratus have tetrodotoxin (TTX). TTX is a non-protein, heat resistant molecule which binds to voltage-gated sodium channels of musculatory and nervous system. Ingestion of the fish can cause a wide variety of effects from mild toxications to death. This study is the first toxicity report of L. sceleratus for Cyprus. Due to the lack of data on toxicity levels of L. sceleratus, and some cases of poising after the ingestion of the fish were the reasons for the start of this work. 24 L. sceleratus were sampled from 3 different areas to represent Northern Cyprus, during one year period. 16 fish samples selected and grouped into 4 fishes per season for toxicity assay. TTX levels from liver, gonad, intestine, muscle and skin tissue homogenate were analyzed with TTX ELISA. Totally 80 tissues were analyzed, 40% of them were above the toxic limit (2.2 µg/g). Most toxic tissue, according to the seasonal average, was found in the summer season and was determined as; Liver = 13.48 µg/g. Most toxic three fishes were found to be female with a length of 45-60 cm. TTX distribution among tissues have similarities with previously published studies from different regions.