9550699 Maleque Meharry Medical College seeks funding for research that would investigate the influences of the ODC/polyamine system on the process of neuronal differentiation by examining the interactions between the ODC/polyamine system and GAP-43. Furthermore, the signal transduction pathways that may modulate these crucial elements of neuronal differentiation will also be investigated. The three specific aims of this work are: (1) Determine the developmental profiles of ODC, GAP-43 (activity, protein and m-RNA) and the polyamine in the postnatal cerebellum and neo-cortex; (2) compare the relationship between the ODC/polyamine system and GAP- 43 and to test their interdependence through inhibition of ODC activity by DFMO; (3) study common signal transduction mechanisms that may modulate both the ODC/polyamine system and GAP-43. This would be accomplished through examination of PKC activity and the expression of isoforms and PI turnover. Three graduate students will participate in the proposed work. ***