"I'd appreciate it if you'd try and keep us in the _____ on this."

And the correct answer is loop. According to the Google Dictionary, the American English idiom "to be in or out of the loop means "to be part of a group of people that is dealing with something important, or to not be part of this group." The expression has become very popular in recent years, and today "in the loop" is replacing  "on the inside track", an older British idiom. EXAMPLE: "Just to keep you in the loop, I heard she had a two-hour meeting with management yesterday and it didn't go very well."

Because information is power, being in the loop or out of the loop can be of enormous importance in today's workplace. But how does one get into it? Well, if you share information with people, there's a good chance they'll remember that fact and they'll then keep you "up-to-date" about what's going on. As a result, when something interesting happens, you won't have to say, "Oh, I was out of the loop on that."

In the Loop was the name of a 2009 film in which the US President and UK Prime Minister think that a war might help solve their problems. Trans-Atlantic differences in language, however, lead to conflict and comedy.