Brain Of Cichlid Fish Research Articles

Induction of reactive oxygen species in brain of Etroplus maculatus after exposure to bisphenol A

The present study was aimed to investigate that bisphenol A, an environmental estrogen, exposed at 648 ?g/ L concentration for 96 h could induce reactive oxygen species in brain of cichlid fish, Etroplus maculatus. Evaluation of antioxidant enzymes as superoxide dismutase, catalase and glutathione reductase showed a reductionin the activities at 5% level of significance with concomitant increase in the level of hydrogen peroxide generation (from 1.546 ± 0.426 (control), 1.506 ± 0.217 (DMSO) to 1.888 ± 0.368 (24 h), 5.332 ± 0.589 (72 h), 2.392 ± 0.341 (96 h)) and lipid peroxidation (from 2.805 ± 0.33 (control), 2.401 ± 0.309 (DMSO) to 3.596 ±0.373 (24 h), 5.65 ± 0.306 (72 h), 3.834 ± 0.236 (96 h)). The brain marker enzyme, acetylcholinesterase decreased at 24, 72 and 96 h in time-dependent manner than that of control groups. The present findings summarize that the increased production of oxygen free radicals due to the exposure of an environmental estrogen, bisphenol A at sub lethal concentration (648 ?g/ L) for 96 h inhibited the activities of antioxidant enzymes thereby induced oxidative stress in brain of fish. The decreased activity of brain marker enzyme, acetylcholinesterase reflect the neurotoxicity of bisphenol A in brain of fish, Etroplus maculatus and this could be one of the possible mechanisms of bisphenol A-induced neurodevelopmental disorders in fish.

Nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase activity in the brain of a cichlid fish, with remarkable findings in the entopeduncular nucleus: a histochemical study

In the entire brain of the African cichlid fish, Haplochromis burtoni, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity was visualized histochemically in fewer nuclei compared to other teleost fish. Intensively labeled perikarya were found in the ventral hypothalamic area, the nucleus of the medial longitudinal fascicle, the nucleus of the midbrain tegmentum, the nucleus of the lateral longitudinal fascicle, the trigeminal motor nucleus and the octavolateral area. Compared to other NADPH-d labeled nuclei in the brain, we saw an unusual localization of NADPH-d activity in the rostral, dorsal, ventral and caudal part of the entopeduncular nucleus. Additionally, some isolated perikarya of different morphological appearance were found at the levels of the preglomerular nucleus, the diffuse nucleus of the lateral torus and the lateral longitudinal fascicle. A widespread distribution of labeled fibers was identified throughout the brain. The remarkable NADPH-d activity, particularly in the entopeduncular nucleus, differs significantly from the existing data on other teleosts. Taking into account the sensory functions of the entopeduncular nucleus described in other vertebrates, the massive NADPH-d activity in this nucleus may indicate an important role of NADPH-d in the modulation of sensory functions.

Brain creatine kinase activity during ontogeny of the cichlid fish oreochromis mossambicus and the clawed toad xenopus laevis, influence of gravity?

The development of creatine kinase (CK) activity was studied in the brain of cichlid fish and clawed toads. The activity of CK in the whole brain of the fish decreases immediately after hatching (stage 6) from values of about 135 nmol substrate cleaved/mg protein/min to a value of about 105 at stage 8 (5 days post hatch at 20°C). With the exception of a significant peak (125 nmol) between stages 9 and 10 (7 and 9 days respectively, post hatch at 20°C) and a small intermediate peak at stages 12 and 13 (about 10 days post hatch at 20°C) a constant level of about 100 nmol cleaved substrate is maintained until maturity. In contrast, CK activity was determined to be 3-fold higher in the whole brain of the clawed toad. With the exception of two significant peaks at stages 47 and 49 (5 and 12 days respectively, post fertilization at 23°C) a value of about 360 nmol was found during larval development and metamorphosis, as well as in the adult brain. In investigating the possible influence of gravity on CK activity during early ontogeny of the brain both animal species were exposed to hyper-gravity (3±1 g) for 7 days. A significant decrease of total CK activity of 20% was found in the fish brain and of about 5% in the toad. Changes in total CK activity during brain development, as well as after the influence of altered gravitational forces, suggests that this enzyme is well adapted to critical phases of brain development and reacts very sensitively during this period to changes in environmental conditions.