Changes in the Content of Glial Fibrillary Acidic Protein in the Frontal Cortex of Rats during Conditioned Active Avoidance Training

We studied the dynamics of expression of glial fibrillary acidic protein (GFAP) in the frontal neocortex of rats during training for conditioned active avoidance reaction (CAAR). The GFAP content in a cytoskeletal fraction of the frontal cortex tissue was quantitatively estimated with the use of solid-phase immunoenzyme analysis, 2 h and 1, 3, 7, 14, 21, and 30 days after the beginning of training of the animals. It was found that the changes in expression of the filamentous form of GFAP in the neocortex are clearly pronounced and possess a three-phase pattern: the level of GFAP significantly increased within the first hours after the beginning of CAAR training, within 7-14 days this index decreased and became smaller than that in the initial state, and then again rose (with a maximum after 21 days). The obtained data indicate that the neurospecific protein under study is involved in the processes of learning and formation of conditioned memory engrams.