Serotonergic and dopaminergic characterization of human mixed brain culture. a Cells at DIV24 were fixed and ICC with 5-HT antibody revealed presence of serotonergic cells in the culture. The arrows indicate representative cells positive for 5-HT staining. The inset is an area magnified to better visualize 5-HT positive staining. b Western immunoblotting of the cell lysates indicates presence of GABAergic neurons (detected by glutamate decarboxylase antibody) in the culture. Number of GABAergic neurons gradually increase as the culture progresses. In contrast, dopaminergic neurons (detected by tyrosine hydroxylase antibody) are abundant in the initial time points of the culture and gradually decrease as the culture progresses.