To check this effect, (As per I have read somewhere in one journal), The animal of Control group is placed in one closed chamber and measure the time required to produce the convulsion. After that put another animal - Test group (Which has been treated with L-thyronine) and measure the time for convulsion. Compare these readings.
As L-thyronine increases respiratory rate, the time required to produce convulsion in test group will be lesser compared to control group (animal).
Unfortunately currently I don't have the reference for this method, but soon provide it for conduction of such practical...