A third consecutive defeat was perhaps undeserved for Sam Allardyce's team, but apart from one golden opportunity for out of touch Nicolas Anelka, Wanderers did little to trouble keeper Chris Kirkland.
McCulloch at 27th minute substitute for ex-England International Emile Heskey, certainly showed the Frenchman how to finish.
The £8 million marksman was put clean through on Kirkland by the outstanding El Hadji Diouf's slide-rule ball. But with only one goal to his name since moving to the Reebok - a Carling Cup strike at Walsall - the ex-Liverpool, Arsenal and Real Madrid frontman is struggling for confidence. Anelka's left foot shot from 20 yards flew into the barracking Wigan supporters instead of nestling in the back of the net.
Had they got in front Bolton may have prospered from it, instead, Wigan matched their host's industry and work rate.
And they did so having to make two substitutions before the interval.
Heskey limped off after an earlier clash with Ivan Campo and then Gary Teale pulled up with a hamstring problem to be replaced by David Cotterill.
Bolton, after their four-nil mawling by Manchester United the previous week, made one change from that game. With skipper Kevin Nolan still suspended, Henrik Pedersen came in at left back for his first Premiership start of the season, allowing Tal Ben-Haim to take Nicky Hunt 's place at right back to counter the threat of Kevin Kilbane.
Bolton should definitely have been ahead when Diouf seized upon Andy Webster's error to give Anelka his chance.
A disjointed first half was held up after 20 minutes when Kevin Davies caught Kirkland in the face with a flying arm. The Bolton striker escaped a booking but the goalie needed several minutes of treatment before being able to continue.
Diouf looked the most likely to break the deadlock. A strong run past three defenders, including a static Webster, finished with a shot that flew over the bar.
Wigan hadn't created a worthwhile chance until McCulloch's arrival. But he headed over on the half hour from Emmerson Boyce's centre though Kilbane looked better placed behind him to reach the ball.
Just before the break Davies was yellow-carded for sarcastically applauding a foul in his favour by referee Mark Clattenburg and Bolton had the ball in the net through Stelios Giannakopoulos only to have his effort ruled out for offside. TV replays suggested the Greek midfielder was onside but Bolton's luck was out.
In the second half there were even fewer worthwhile chances at either end so Davies, who hadn't scored since the first day of the season, glanced a Gary Speed corner fractionally wide.
Davies eventually gave way to Ricardo Vaz Te with 17 minutes left but it was McCulloch who settled the game with his fiercely struck drive beyond Jussi Jaaskelainen.
The Finland keeper, who recently saved two penalties at Blackburn, moved smartly to beat away a Cotterill shot as Wigan looked to double their advantage in the closing stages.