He particularly studied neurofibrils, and was known for improving microscopic techniques for dealing with tissue samples.
[1] Apáthy was born in Budapest where his father was a professor of international law.
After high school he went to study medicine and worked at the institute of pathology.
He took a special interest in neurohistology and conducted studies on marine Hirudines, making use of techniques such as the injection of gold chloride to visualize the neural network.
After World War I he became more politically active and the Hungarian Republic appointed him to Romania as commissioner of Transylvanian affairs but his outspoken views led to his imprisonment in Sibiu.