3.2.3. The 6 hertz (6 Hz) Psychomotor Seizure Test

In the 6 Hz test, psychomotor seizures were induced via corneal stimulation (6 Hz, 32 mA, 0.2 ms rectangular pulse width, 3 s duration) using a constant-current device (ECT Unit 57800, Ugo Basile, Italy). A drop of 1% solution of lidocaine hydrochloride (Polfa Warszawa, Warsaw, Poland) was applied to the mouse corneas before stimulation to provide local anesthesia and ensure optimal current conductivity. After the electrical stimulation, mice were gently released and observed for the presence or absence of seizure activity, being characterized by immobility associated with rearing, forelimb clonus, twitching of the vibrissae, stun, and Straub-tail (Brown et al. 1953, Barton et al. 2001). Mice resuming normal behavior within 10 s from the stimulation were considered as protected [27,28].