cDNAs related to pentylenetetrazol-induced bursting activity in neurons were screened by a differential hybridization method using normal and pentylenetetrazol-treated primary cultured neurons from the cerebral cortex of mice. Twenty clones of candidate cDNA with expression increased or decreased by treatment with pentylenetetrazol were obtained. One of them, PTZ-17, was sequenced. Injection of PTZ-17 derived RNA into Xenopus oocytes showed a large calcium inward current with extracellular application of pentylenetetrazol.