Several recent experiments on developing chick spinal cord have established a time window when the developing spinal cord changes from a permissive to a restrictive environment for regeneration. This time window occurs during embryonic days 13-14 (E13-E14) of chick development. Recent experiments in adult rat, have found two proteins that actively inhibit axonal regeneration. This study has sought possible inhibitory proteins, in chicks, correlating to this temporal change. Proteins continuously present after this change (E14-E20) but not before (E11) were identified. Two-dimensional gel electrophoresis was used for separatation of the proteins. Seven protein spots of interest demonstrated this correlative late-expressing neural protein (LNP) profile. Although the functions of these proteins could not be ascertained in this study, further investigation is warranted. / Science, Faculty of / Zoology, Department of / Graduate