Abstract: The ploysialic acid (PSA) modification of neural cell adhesion molecules (NCAMs) not onlymodulates cell interaction of neural development but also plays an important role in learning andmemory. The endoneuraminidase NE (endo-N) which specifically removes a-2, 8 linked polysialic acidfrom NCAM was used to assay the functional role of PSA in the chicks memory retention. Thememory retention of day-old chicks was significantly impaired after a localized injection of endo-N intoIMHV. The dose lower than 4μg had no significant effect. The improvement effect of prenatalcorticosterone on memory retention of dark hatched chicks was retarded with endo-N administrationintraplacentally on the embryonic day 20. All these suggested that PSA of NCAM might be involved inmemory retention of chicks and synaptic plasticity during brain development.

Key words: chicks, polysialic acid, embryonic period, memory retention