Why did Professor Donghai abandon his brother?

Hate my brother. According to the questioning film Bear in Xiong Xin, Professor Donghai's younger brother was loved by his parents since childhood. Professor Donghai felt that his younger brother had taken away his parents' love and abandoned his younger brother when there was a fire in the laboratory. Professor Donghai is the villain in the bear haunted series "Bear haunted my bear core". In the first half of the film, he ran around with the leading group and acted honestly. With the development of the movie plot, Donghai finally showed his truly evil face.