cult us sitcoms like the big bang theory and how i met your mother will be taken off air for 12 hours .
the specially-produced advert will be played , featuring ` darren ' -- the man fictionally in charge of keeping e4 on air , sitting in the channel 's control room .
e4 's regular schedule will be suspended from 7 am , when polls open , to 7 pm , three hours before polling closes .