INFLUENCE OF GROWTH-FACTORS ON NEURONAL DIFFERENTIATION

With so many neurotrophins and receptors now known, how is our picture of neurotrophism changing? Recent studies on knockout mice have confi rmed our expectations of neurotrophin action in neuronal development. A notable exception is the activation of TrkB, on motor neurons, by an unknown ligand. It is also clear that some neurotrophins have diverse activities and influence early developmental stages. There are intere sting new data concerning the role of p75, the low affinity neurotroph in receptor, as a modulator of neurotrophin activity. Even more exciti ng are new studies on glia-derived neurotrophic factor (GDNF) which de monstrate that this growth factor acts as a potential protector of mot or neurons and striatal dopaminergic neurons.