The invention relates to the novel identification of inhibitors of phosphodiesterase type 4 ("PDE4") as agents which can reverse inhibition of neural regeneration in the mammalian central and peripheral nervous system. The invention provides compositions and methods using agents that can reverse the inhibitory effects on neural regeneration by regulating PDE4 expression. A composition comprising at least one PDE4 inhibitor in an amount effective to inhibit PDE4 activity in a neuron when administered to an animal is provided. Methods for regulating (e.g., promoting) neural growth or regeneration in the nervous system, methods for treating injuries or damage to nervous tissue or neurons, and methods for treating neural degeneration associated with disorders or diseases, comprising the step of administering to an animal a composition comprising a therapeutically effective amount of an agent which inhibits phosphodiesterase IV activity in a neuron are provided.