Modulators of signal transduction pathways can promote axonal regeneration in entorhino-hippocampal slice cultures.

Axonal regeneration after lesions is usually not possible in the adult central nervous system but can occur in the embryonic and young postnatal nervous system. In this study we used the model system of mouse entorhino-hippocampal slice cultures to assess the potential of pharmacological treatments with compounds targeting signal transduction pathways to promote growth of entorhinal fibers after mechanical lesions across the lesion site to their target region in the dentate gyrus. Compounds acting on the cyclic AMP-system, protein kinase C and G-proteins have been shown before to be able to promote regeneration. In this study we have confirmed the potential of drugs affecting these systems to promote axonal regeneration in the central nervous system. In addition we have found that inhibition of the phosphoinositide 3-kinase pathway and of the inositol triphosphate receptor also promoted axonal growth across the lesion site and are thus potential novel drug targets for promoting axonal regeneration after central nervous system lesions. Our findings demonstrate that slice culture models can be used to evaluate compounds for their potential to promote axonal regeneration and that the pharmacological modulation of signal transduction pathways is a promising approach for promoting axonal repair.