In experiments on male albino rats it was established that the aporphine alkaloid 7-hydroxyglaucine injected i.p. at a dose of 1/10 of the LD50 induced many changes in the brain level of biogenic amines. Serotonin content was significantly increased in all brain structures studied (whole brain. cortex, striatum, and hypothalamus) Dopamine level was increased in the whole brain and cortex and was decreased in the hypothalamus; noradrenaline level was increased in the cortex and was decreased in the whole brain and hypothalamus. These effects are thought to be due to the 7-hydroxyglaucine-facilitated transport of amino acids, precursors of biogenic amines, and to neurotransmitter interactions in the different brain structures.