Glenn Howerton, best known for his work on “It’s Always Sunny in Philadelphia,” is channeling one of his 10th grade teachers to play a disgraced Harvard philosophy scholar who must take a job as a high school Advanced Placement biology teacher in the new NBC comedy “A.P. Bio," airing at 9:30 p.m. Thursdays. 

“I had a really good theater teacher that year. In many ways there are a lot of parallels between him and this role,” Howerton says. “He was a slightly disgruntled actor. There was a little bit of bitterness there.

“The main thing was that he didn’t treat us like we were kids but treated us like we were adults, and I respected that. I’ve never liked being talked to like I am a kid, and I try not to talk to my kids like they are kids. I am their dad and they have to do what I say, but I never treat them like they’re dumber than me.”

The high school memory was one of the reasons Howerton was excited about the prospect of taking on the NBC comedy. He knows his character of Jack Griffin is a bit of a jerk (Howerton uses a more colorful phrase to describe him) when he takes over the class at Whitlock High School and doesn’t treat the students with kid gloves.

What he also doesn’t do is teach any biology, much to the frustration of the school principal (Patton Oswalt). Griffin is upset he’s lost a big job to a rival and decides to use the students to get revenge. The way Howerton sees it, the character may not be doing what a traditional high school biology teacher would be doing — like teaching — but he’s doing something more important in mentoring the students to think on their own.

Howerton describes his years at Jefferson Davis High School in Montgomery, Ala., as being a time when he was both thinking on his own and still not certain of what to do.

“There was a part of me that was questioning authority, questioning everything. At the same time, I was not comfortable being a person of authority myself,” Howerton says. “In some ways I was oddly too mature, but in other ways I was immature.”

He became mature enough to graduate from Juilliard School’s Drama Division. From there he began his acting career, including “That ’80s Show,” “ER,” “The Mindy Project” and “Fargo.” As for taking on the starring role in “A.P. Bio” while “It’s Always Sunny in Philadelphia” is still in production for at least two more seasons, Howerton explains the way the cable series works is they all get together when they can and make new episodes.

Working on “Sunny” is a dream job for Howerton because the cable series isn’t under the kind of network pressure of having to produce a certain amount of episodes in a limited amount of time. The “Sunny” team is willing to take as long as is necessary to make sure each script is the best it can be.

Howerton is quick to stress he’s still officially part of the “It’s Always Sunny in Philadelphia” cast but, he was looking for a project that would let him show other aspects of his comic skills.

“One of the tough things about doing a show for 12 years is people might have a hard time seeing you as anything else, and I realize that that could be a little bit of a struggle for me as an actor,” Howerton says. “But that’s why it was important for me to get to do something with someone who has a distinctive voice Mike (O’Brien). I wasn’t even planning on jumping into anything else. But when I read the script and saw it was Lorne Michaels and Seth Meyers, I couldn’t pass it up. But mostly, I just loved the script and the character.”

Going from such a free working environment to the more set ways of network television worried Howerton a bit. After he read the script for the first episode, Howerton wasn’t convinced the network would let them make the show as written because it was so different from a standard sitcom. It wasn’t until he sat down with writers and executive producers — O’Brien, Michaels and Meyers — that Howerton knew there was nothing to fear.

“They told me that the network wanted them to do something different,” Howerton says. “They wanted something that felt a little bit more like a cable show and a little more edgy. So, the best of my knowledge, the network never made us take out anything that was too mean or goes too far.

“I was the one who thought that maybe my character was a bit too mean.

Howerton would love to have the kind of real world problem of juggling two series for a long time because he likes his “A.P. Bio” character so much.

“I can relate to him because I have taught classes and been a camp counselor,” Howerton says. “I always liked doing different things as a teacher because if you have their respect, have their attention, they will actually listen to you.”

That’s a philosophy that also can be applied to TV viewers as Howerton proved with “Sunny” and wants to match with “A.P. Bio.”