Nerve Growth Factor in CNS Repair and Regeneration

Abstract

Increasing recognition is given by neuroscientists to the fact that considerable plasticity is retained even in the adult mammalian central nervous system (CNS), i.e. that maintenance and function of adult CNS neurons continue to depend on and be regulated by agents presented to them by their humoral, extracellular matrix and cellular micro-environments. One major class of macro-molecular regulatory agents is that of special proteins controlling the performance of selected target neurons named neuronotrophic factors (NTFs), of which Nerve Growth Factor (NGF) is the first discovered and best characterized representative (Levi-Montalcini, 1987). NGF and other newly recognized NTFs have been traditionally investigated in the context of lesions in the peripheral nervous system (PNS) and in the course of their early development, both in vivo and in vitro. A recently articulated CNS neuronotrophic hypothesis (Varon et al., 1984) has proposed that i) adult CNS neurons also require support from their own NTFs, and ii) relative deficits of endogenous NTF may underlie neuronal damages in experimental and pathologic situations, and iii) exogenous NTF administration may reduce or prevent neuronal damage in such situations.