Complex sentence: The growing importance of molecular biology led Brown & Colquhoun to apply to the Wellcome Trust in 1990 and they funded the establishment of the Wellcome Lab for Molecular Pharmacology which Colquhoun directed until his retirement in 2004.
Split into simpler sentences: The growing importance of molecular biology led Brown & Colquhoun to apply to the Wellcome Trust in 1990. They funded the building of the Lab for Molecular Pharmacology which Colquhoun directed until his retirement in 2004.