Polypeptide growth factors in mammalian development: some issues for neurotoxicology and behavioral teratology.

Protein molecules known as Growth Factors (GFs) appear to play an important regulatory role in a number of CNS functions. In particular Nerve Growth Factor (NGF), the best characterized among about 30 GF molecules, is endowed with specific activities on cholinergic and peptidergic CNS neurons. Indexes of neurobehavioral maturation are accelerated in the mouse by neonatal NGF exposure, while a similar treatment with EGF exerts both growth-promoting and growth-inhibiting effects on somatic and behavioral development. Scopolamine hyperactivity is enhanced around weaning by NGF pretreatment. Data are discussed along with (a) NGF prevention of cholinergic system damage and (b) the molecular mechanism of endogenously-triggered CNS repair processes.