Stimuli that evoke seizure are capable of inducing structural changes in the hippocampus. However, late‐acting genes related to these changes have not been described. Administration of pentylenetetrazole (PTZ; 50 mg/kg) to rats of various ages evoked tonic‐clonic seizures. Using RNA gel blot analysis we found that the level of the mRNA for microtubule‐associated protein 1B (MAP1B) was robustly increased in the hippocampus of 3‐month‐old rats. The levels of MAP1B mRNA in hippocampus peaked at 40 h and began to decline by 72 h following PTZ treatment. Immunoblotting with anti‐MAP1B antibody demonstrates the increase in content of immunoreactive proteins 40–72 h after seizure onset in the hippocampus of PTZ‐treated rats. These results indicate that MAP1B is a sensitive indicator of hippocampal structural changes occurring in response to PTZ‐induced seizure activity.