(CNN) -

Actor Seth Rogen spoke at a Senate hearing on Capitol Hill Wednesday, addressing Alzheimer's disease and how it has affected his wife's family.

Known for his roles in comedies such as "Knocked Up," "Pineapple Express" and "Freaks and Geeks," the actor brought some of his trademark humor to his speech but didn't mince words when it came to discussing what he called "the ugly truth" of the disease.

The hearing, called "Taking a Toll on Families and the Economy: The Rising Cost of Alzheimer's in America," gave Rogen a chance to speak about his own experience with the disease, which afflicts his mother-in-law. While Rogen said he initially thought of symptoms as being little things like forgetting where you left your keys, he soon saw what damage it could really do.

"My mother-in-law, a teacher for 35 years, forgot how to speak, feed herself, dress herself, and go to the bathroom herself, all by the age of 60," Rogen told the audience.

Rogen started a charity fund, Hilarity for Charity, in 2012 to raise money to help families battling Alzheimer's and for research. The first event, held in Los Angeles in 2012, raised more than $300,000 and brought big names such as Bruno Mars, Tenacious D and Patton Oswalt to perform.

Rogen mentioned in his speech that Hilarity for Charity recently started a college program called HFC U to inspire students to hold their own events and told the Senate that 18 schools have signed up to hold events so far.

While Rogen stayed witty and on-point during the hearing, he took to his Twitter account to point out that only a few senators were present for his speech.

"@Sethrogen Not sure why only two senators were at the hearing. Very symbolic of how the Government views Alzheimer's. Seems to be a low priority."

Rogen also snapped a photo of the audience he gave his speech to, calling out all the absent senators as part of the problem.

"@Sethrogen All those empty seats are senators who are not prioritizing Alzheimer's. Unless more noise is made, it won't change."

One of the senators in question, Sen. Mark Kirk, R-Illinois, tweeted about Rogen's speech but was not actually present for it. Rogen was quick on the draw for that one.

Mark Kirk ? @SenatorKirk

"Thanks to @Sethrogen for speaking out about efforts to #ENDALZ. RT if you know someone affected by #Alzheimers. pic.twitter.com/KTDIxPaMXU"

Seth Rogen ? @Sethrogen

".@SenatorKirk pleasure meeting you. Why did you leave before my speech? Just curious."

In the end, Rogen said that he wanted to use his voice to reach out to others.

"I'm here simply to show people that they're not alone," Rogen said. "So few people share their personal stories. So few people have something to relate to. I know that if me and my wife saw somebody like me talking about this, we would feel less alone."