Actor Seth Rogen has lambasted the American politicians who failed to turn out to hear him speak about Alzheimer's disease at a committee hearing in Washington, D.C. on Wednesday.

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Rogen visited Congress to testify before a group of senators about research, treatment and prevention of the condition, which his mother-in-law suffers from.

However, the "Knocked Up" star later took to Twitter to express his disappointed by the lack of support shown for the cause, writing, "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."

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He added a picture of the almost empty room, writing, "All those empty seats are senators who are not prioritizing Alzheimer's. Unless more noise is made, it won't change."

Rogen even addressed one of the senators directly on the micro-blogging site, asking Illinois' Mark Kirk, "Why did you leave before my speech? Just curious."

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Kirk later replied to the actor and revealed he had a meeting to attend.

Rogen is a longtime supporter of Alzheimer's research and even co-founded a charity with his wife to help raise awareness and funding.