Example 37
In MES test, the ability of different doses of the test compound in preventing seizure induced by an electrical stimulus of 0.2 s in duration (50 mA at 60 Hz), delivered through the corneal electrodes primed with a drop of anesthetic/electrolyte solution (0.5% tetracaine hydrochloride in 0.9% saline) is tested. Mice are restrained by hand and released immediately following corneal stimulation that allows for the observation of the entire seizure episode. A maximal seizure in a test animal includes four distinct phases that includes, hind leg flexor component tonic phase (Phase I), hind leg extensor component of the tonic phase (Phase II), intermittent, whole-body clonus (Phase III), and muscular relaxation (Phase IV) followed by seizure termination (Woodbury & Davenport, 1952; Racine et al., 1972). Test compounds are tested for their ability to abolish hind limb tonic extensor component that indicates the compound's ability to inhibit MES-induced seizure spread. Compounds are pre-administered (i.p) and tested at 0.25, 0.5, 1 and 4 h time points for the abolishment of hind limb tonic extensor component after electrical stimulus.
