....club Harrogate Town on a month`s loan from National League side Lincoln City to act as cover for the injured Luke Shiels and Dave McGurk.
Brown brings a wealth of experience and presence and will be available for selection on Saturday.
He has had three separate spells with Lincoln, with his current stint starting following his arrival from Macclesfield Town in the summer of 2013.
He first joined the Imps from Huddersfield Town in 2005, having worked his way through the youth system at the Yorkshire side.
He played in a number of positions, before settling in a central defensive role, and went on to make over eighty appearances for the Terriers, including over fifty starts in the Football League.
He was a regular in the City side until a wrist injury sustained towards the end of the 2005/06 season and required surgery during the summer break, forced him to miss the first thirteen matches of the following campaign.
His final League outing in an Imps' shirt came at Peterborough United in March 2008 and following his departure from Sincil Bank with over 100 appearances to his name he had a brief spell at Wrexham before linking up with Keith Alexander and Gary Simpson at Macclesfield Town.
He returned to the club on loan from Macclesfield in March 2013 and following his release by the Silkmen, came back to Sincil Bank on a permanent deal.
Meanwhile, Andy Gascoigne has signed for Matlock Town in a month loan deal which sees him get much-needed match minutes and game time.
The move is part of Gascoigne's return to form and match fitness, which will see the player return ready to play once again in the first-team.
Manager Simon Weaver has said on both Gascoigne going out on loan and Nat Brown joining: "Gazza is going out now to gain some much-needed minutes on the pitch. We want him to come back ready for action. We are excited about including him on his return.
“Nat has a wealth of experience and offers size and no-nonsense defending. We are very pleased that he has joined us."