Inducing efÞ cient catecholaminergic differentiation of GFAP, SOX2-positive neural progenitors (NHA) by means of kinetic factors

Extensive research has been performed to control differentiation of neural stem cells. For last three years we have strived to obtain stabilized protocol of catecholaminergic differentiation of GFAP, SOX2- positive neural progenitors (NHA) In 2007 we published fi rst results presenting differentiation of GFAP positive neural progenitors (NHA) in accordance to model of discordant phenotypes suppression (Rieske 2007, Eur J Neurosci). Since the beginning of 2008 we are able to differentiate uncommitted GFAP and SOX2 positive neural progenitors (NHA) in different environmental conditions to: only neural cells consisted of neuronal and glial cells, or fi broblast-like cells, or mixture of neural and fi broblast-like cells (Witusik 2007, Brain Res; Witusik 2008 BMC Biotechnol). In spite of successful blockade of fi broblast-like differentiation by means of environmental changes, we were able to barely increase the percentage of neuronal (GABA-ergic and catecholaminergic) over glial cells under several different cell culture testing conditions. It was so far also impossible to alter radically ratio catecholaminergic /GABA-ergic cells by means of changing environmental factors (SHH, GDNF, bFGF, EGF, BMPs). It strongly suggested infl uence of stochastic events or so called continuum processes during neuronal versus glial, and catecholaminergic versus GABA-ergic differentiation of described neural progenitors. Nevertheless including kinetic factors to our differentiation protocols allowed to increase percentage of catecholaminergic cells from 10 to 45% of neuronal cells.