when the acute effects of the n- , o2- and o4-isopropyl derivatives of barbital ( nib , o2ib ) , o4ib on the concentrations of brain biogenic amines were determined , it was found that nib and o4ib increased the serotonin concentrations in several brain regions examined without markedly changing the 5-hydroxy-indole acetic acid ( 5-hiaa ) concentrations ;
C0006104
brain
C0086045
concentrations