Part of the book: Neurochemistry
The fish brain has a unique feature of vertebrates—it grows with the growth of body over a lifetime. In this regard, fishes are a convenient model for the study of embryonic and postembryonic development of the central nervous system and of the influence of different factors on these processes. Currently, the mechanisms of adult brain morphogenesis of fish, which retain larval stage for a long time, are poorly understood. This is particularly true for participation of radial glia during morphogenesis of the brain, as well as the presence and distribution of the proliferative zone in the adult fish brain. Another interesting and little known aspect is the posttraumatic ability of fish to form active neurogenic niches. Investigation of the structural organizations of neurogenic niches and special conditions of the extracellular environment, as well as the interactions between neighboring cells in a neurogenic niche, is interesting and relevant direction in the study of the neuronal stem cells biology. Injury of fish brain creates special conditions for the implementation of genetic programs aimed at strengthening the proliferation of progenitor cells, as well as the activation and proliferation activity in the neuronal stem cells.
Part of the book: Peripheral Nerve Regeneration
The H2S-producing systems were studied in trout telencephalon, tectum, and cerebellum at 1 week after eye injury. The results of ELISA analysis have shown a 1.7-fold increase in the CBS expression at 1 week post-injury, as compared to the intact trout. In the ventricular and subventricular regions of trout telencephalon, CBS+ cells, as well as neuroepithelial and glial types, were detected. As a result of injury, the number of CBS+ neuroepithelial cells in the pallial and subpallial periventricular regions of the telencephalon increases. In the tectum, a traumatic damage leads to an increase in the CBS expression in radial glia with a simultaneous decrease in the number of CBS immunopositive neuroepithelial cells detected in intact animals. In the cerebellum, we revealed neuroglial interrelations, in which H2S is probably released from the astrocyte-like cells with subsequent activation of the neuronal NMDA receptors. The organization of the H2S-producing cell complexes suggests that the amount of glutamate produced in the trout cerebellum and its reuptake is controlled with the involvement of astrocyte-like cells, reducing its excitotoxicity. We believe that the increase in the number of H2S-producing cells constitutes a response to oxidative stress, and the overproduction of H2S neutralizes the reactive oxygen species.
Part of the book: Neuroprotection - New Approaches and Prospects