Migration, of neurons

A hereditary disease common in Japan results from a defect in migration of neurons and is associated with brain malfonnation as well as muscular dystrophy. In nemaline myopathy a defect in nebulin leads to progressive weakness and often to death in infancy. 

Jin K, Sun Y, Xie L, Peel A, Mao XO, Batteur S, Greenberg DA (2003) Directed migration of neuronal precursors into the ischemic cerebral cortex and striatum. Mol Cell Neurosci 24 171-189... 

Lois, C., Garcia-Verdugo, J. M., and Alvarez-Buylla, A. (1996). Chain migration of neuronal precursors. Science 271, 978-981. 

Nowakowski RS, Rakic P (1981) The site of origin and route and rate of migration of neurons to the hippocampal region of the rhesus monkey. J Comp Neurol 196 129—154. 

As already pointed out, cells in the late phases of proliferation are born in radial columns of which the Muller cells form the core. The columnar organization is also found in other areas in the brain such as cortex (Rakic, 1972 Luskin et al., 1988), spinal cord (Leber et al., 1990), and optic tectum (Gray and Sanes, 1991) where the radial glia act as a scaffold for the migration of neurons (Hatten, 1990, 1993 Rakic et al., 1994 Rakic, 1995). Muller cells probably play an important role in guiding the clonal cells in columns. 

Experiments that reveal the effects of alcohol on nerve cells of the prenatal developing brain in humans are not feasible, but animal experiments show that exposure of the fetus to a relatively low level of ethyl alcohol in maternal and fetal blood promotes significant changes in the migration of neurons to... 

Numerous behavioral measures have been evaluated for their usefulness in providing a sensitive index of exposure to ionizing radiation. Radiation-related mental retardation is the most likely type of behavioral abnormality in humans sensitivity peaked between 8 and 15 weeks of conception and doses >0.4 Gy. No specific mechanism for the production of mental retardation has been established, although proposed mechanisms include the loss of cells, migration of neurons, and failure of synapto-genesis. In studies with rats, operant responses decreased (maintained by positive reinforcement such as food or water) at sublethal radiation doses (3.0-6.75 Gy) under various schedules of reinforcement. Dismpted operant responses under shock avoidance at >LD100 levels are reported in pigs and rhesus monkeys. 

Removal of polysialic acid by treatment with endosialidase has demonstrated the involvement of polysialic acid in dynamic cellular processes as varied as migration of neuronal precursor cells, axonal outgrowth, synaptogenesis, physiological and morphological synaptic plasticity, and control of circadian rhythm [63, 75, 153, 164-174]. One example on the application of endosialidase in cell culture studies is... 

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